Conservative Scientists & its Consequences

[AbruptSLR]

The linked (open access) reference calibrates a dynamic soil feedback scheme to both mid-Holocene & Last Glacial Maximum conditions, and finds that soil represents a substantial positive feedback with a significant amplification in the mid-to-high northern latitudes:

Stärz, M., Lohmann, G., and Knorr, G.: The effect of a dynamic soil scheme on the climate of the mid-Holocene and the Last Glacial Maximum, Clim. Past, 12, 151-170, doi:10.5194/cp-12-151-2016, 2016.

http://www.clim-past.net/12/151/2016/

Abstract: "In order to account for coupled climate–soil processes, we have developed a soil scheme which is asynchronously coupled to a comprehensive climate model with dynamic vegetation. This scheme considers vegetation as the primary control of changes in physical soil characteristics. We test the scheme for a warmer (mid-Holocene) and colder (Last Glacial Maximum) climate relative to the preindustrial climate. We find that the computed changes in physical soil characteristics lead to significant amplification of global climate anomalies, representing a positive feedback. The inclusion of the soil feedback yields an extra surface warming of 0.24 °C for the mid-Holocene and an additional global cooling of 1.07 °C for the Last Glacial Maximum. Transition zones such as desert–savannah and taiga–tundra exhibit a pronounced response in the model version with dynamic soil properties. Energy balance model analyses reveal that our soil scheme amplifies the temperature anomalies in the mid-to-high northern latitudes via changes in the planetary albedo and the effective longwave emissivity. As a result of the modified soil treatment and the positive feedback to climate, part of the underestimated mid-Holocene temperature response to orbital forcing can be reconciled in the model."

[AbruptSLR]

The linked (open access) reference illustrates how consensus (ESLD) science addresses climate change uncertainty using CMIP5 data.  The article acknowledges that this uncertainty is a major stumbling block to effective policy action to address climate risk; however, the article estimates that science will know 20 +/- 10 years in advance of when we are committed to crossing the 2C limit (or from 2025 to 2045 if we are already committed but do not yet know it)


H. Shiogama, D. Stone, S. Emori, K. Takahashi, S. Mori, A. Maeda, Y. Ishizaki & M. R. Allen (2016), "Predicting future uncertainty constraints on global warming projections", Scientific Reports 6, Article number: 18903, doi:10.1038/srep18903

http://www.nature.com/articles/srep18903?trendmd-shared=0

Abstract: "Projections of global mean temperature changes (ΔT) in the future are associated with intrinsic uncertainties. Much climate policy discourse has been guided by “current knowledge” of the ΔTs uncertainty, ignoring the likely future reductions of the uncertainty, because a mechanism for predicting these reductions is lacking. By using simulations of Global Climate Models from the Coupled Model Intercomparison Project Phase 5 ensemble as pseudo past and future observations, we estimate how fast and in what way the uncertainties of ΔT can decline when the current observation network of surface air temperature is maintained. At least in the world of pseudo observations under the Representative Concentration Pathways (RCPs), we can drastically reduce more than 50% of the ΔTs uncertainty in the 2040 s by 2029, and more than 60% of the ΔTs uncertainty in the 2090 s by 2049. Under the highest forcing scenario of RCPs, we can predict the true timing of passing the 2 °C (3 °C) warming threshold 20 (30) years in advance with errors less than 10 years. These results demonstrate potential for sequential decision-making strategies to take advantage of future progress in understanding of anthropogenic climate change."

Edit: The January GISS value was +0.89C, and assuming an adjustment of -0.256 (this is the difference between the GISS baseline and the 1880-1909 preindustrial baseline) this gives a GISTEMP GMST rise of +1.146C.  Now compare this to the uncertainty range in the attached image from Figure 1a of the reference and you will see that we are currently near the upper range of risk per the CMIP5 analysis.

[AbruptSLR]

The linked article indicates that to date climate models have not considered the influence of soot on clouds and how their shapes effect the amount of sunlight energy that makes it to Earth's surface:

http://www.pnl.gov/science/highlights/highlight.asp?groupid=749&id=4192

Extract: "Researchers at Pacific Northwest National Laboratory found that highly irregular and chemically complex soot particles transform into compacted shapes under different atmospheric conditions, affecting their ability to absorb and scatter sunlight.
…
Why It Matters: From camp fires to coal-burning power plants, soot particles are ubiquitous. Their influence on clouds has been largely unexplored, hampering our understanding of their effects on the climate. This study shows that the morphological (shape) properties of soot particles should be included in future climate model simulations. The shape of soot particles, changed by their incorporation into cloud particles, affects how they absorb or reflect and scatter sunlight. This new information is important for climate models to correctly estimate the amount of sunlight energy that makes it to Earth's surface. This information will help the models correctly calculate Earth's energy in/energy out balance—important for understanding the climate—by taking into account the sway soot has over clouds."

See also:
http://www.pnl.gov/science/highlights/highlights.asp?division=749

[AbruptSLR]

The linked reference indicates that CESM projects an increased frequency of atmospheric river (AR) events over Western North America, with continued anthropogenic global warming.  As such AR events are typically associated with major El Nino event, this research likely indicates a increased frequency of major El Nino events (like our current event) in the future:

Samson M. Hagos, L. Ruby Leung, Jin-Ho Yoon, Jian Lu & Yang Gao (6 February 2016), "A projection of changes in landfalling atmospheric river frequency and extreme precipitation over western North America from the Large Ensemble CESM simulations", Geophysical Research Letters, DOI: 10.1002/2015GL067392

http://onlinelibrary.wiley.com/doi/10.1002/2015GL067392/full

Abstract: Simulations from the Community Earth System Model (CESM) Large Ensemble project are analyzed to investigate the impact of global warming on atmospheric rivers (ARs) making landfall in western North America. The model has notable biases in simulating the subtropical jet position and the relationship between extreme precipitation and moisture transport. After accounting for these biases, the model projects an ensemble mean increase of 35% in the number of landfalling AR days between the last 20 years of the twentieth and 21st centuries under Representative concentration pathway 8.5 (RCP8.5). However, the associated extreme precipitation days increase only by 28% because the moisture transport required to produce extreme precipitation also increases with warming. Internal variability introduces an uncertainty of ±8% and ±7% in the changes in AR days and associated extreme precipitation days compared to only about 1% difference from accountings for model biases. The significantly larger mean changes compared to internal variability, and effects of model biases highlight the robust AR responses to global warming."

See also:

http://ww2.kqed.org/science/2016/02/09/california-is-likely-to-be-stormier-with-climate-change/

Extract: "“What we noticed is that the entire West Coast of North America will experience increased atmospheric river frequency,” said Samson Hagos, a Pacific Northwest National Laboratory earth system scientist who led the new study.

That’s largely because a warmer atmosphere can hold more moisture. Which would mean worse floods, more often.

“The strongest atmospheric river events along the West Coast during the 20th century are strongly linked to flood events of historical significance,” said Daniel Swain, a PhD candidate at Stanford who researches extreme weather.

“A reasonable inference to draw from these studies is that the risk of severe flood events along the West Coast will likely increase,” Swain said.

...

Recent research has suggested that higher temperatures linked to global warming exacerbated the intensity of California’s ongoing drought, by drying out the state. It’s far less clear what effect climate change had on the likelihood that such a drought would occur.

“The role of anthropogenic influences on the lack of precipitation is still an open question,” said Kevin Anchukaitis, a paleoclimatologist and earth systems geographer at the University of Arizona. “Different research groups have come to different conclusions.”

Rising temperatures are expected to accelerate evaporation and lead to drier conditions across the West — producing what scientists call hot droughts.

Anchukaitis said atmospheric rivers don’t necessarily affect the conditions that produce hot droughts.

But the “severity and duration” of droughts, Anchukaitis said, “will depend on a complex interplay between temperature increases, uncertain long-term precipitation trends and the punctuated role of drought-busting atmospheric rivers.”"

[AbruptSLR]

The linked article indicates that large-scale atmospheric warming in the winter (including that associated with the NAO, SB and ENSO) are contributing to accelerate Arctic Sea Ice retreat, faster than projected by AR5 (which did not fully count for the described behavior):

Srdjan Dobricic, Elisabetta Vignati and Simone Russo (2016), "Large scale atmospheric warming in winter and the Arctic sea ice retreat", Journal of Climate, doi: http://dx.doi.org/10.1175/JCLI-D-15-0417.1

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0417.1

Abstract: "The ongoing shrinkage of the Arctic sea ice cover is likely linked to the global temperature rise, the pronounced warming in the Arctic, and possibly weather anomalies in the middle latitudes. By evaluating independent components of global atmospheric energy anomalies in winters from 1980 to 2015, the study finds the link between the sea ice melting in the Arctic and the combination of only three well known atmospheric oscillation patterns approximating observed spatial variations of near-surface temperature trends in winter. The three patterns are North Atlantic Oscillation (NAO), Scandinavian Blocking (SB) and El Nino - Southern Oscillation (ENSO). The first two are directly related to the ongoing sea ice cover shrinkage in the Barents Sea and the hemispheric increase of near-surface temperature. By independent dynamical processes they connect the sea ice melting and related atmospheric perturbations in the Arctic either with the negative phase of the NAO oscillation or the negative trend of atmospheric temperatures over the tropical Pacific. The study further shows that the ongoing sea ice melting may often imply the formation of large scale circulation patterns bringing the recent trend of colder winters in densely populated areas like Europe and North America."

[AbruptSLR]

The linked Earth Changes article includes discussion of how climate change is accelerating polar wander.  I am sure that almost all climate models ignore this behavior, but it is actually happening relatively quickly (i.e. significant changes in less than 100-years & see images):

http://planet-earth-2017.com/wandering-poles/

Extract: "Looking at the two satellite pictures taken back in 1979 and in 2003 for the Arctic, we find a considerable erosion of the Ice Cap. However, upon closer inspection it seems that the melting of the Ice Cap is uneven along its perimeter. In fact, when you look deeper at the area encircled in red, it is clear that the ice is building towards Siberia and is moving away from Canada. At the same time, the strength of the Earth’s magnetic shield has decreased 15% on average over the years from 1850 to 2012. During the same period, the south magnetic pole, in the northern hemisphere, has wandered about 1,100 km (685 miles) into the Arctic Circle. “The rate of the magnetic pole’s movement has increased in the last century compared with fairly steady movement in the previous four centuries”, said Joseph Stoner and the Oregon researchers.
…
The rate of shift of the magnetic pole is on the increase and it seemed that in the past decade it had moved a distance close to the distance it moved in the past century. Comparing the two phenomena, there seems to be a relation between the location of the magnetic pole and the location of ice build up; are they both moving towards Siberia in tandem? Recent increase of global warming rate seems to cause the entire ice in the North Pole to melt in the coming few years. Older ice cap will melt while at the same time new ice cap will form over new location."

[AbruptSLR]

As a follow-up to my last post, Reply #1356, about polar wander The following internet summary is related to the new article in Nature entitled:
Rapid ice melting drives Earth’s rotational pole to the east, by Chen et al 2013:

http://www.csr.utexas.edu/personal/chen/publication.html

and here is a link directly to the preprint pdf:

ftp://ftp.csr.utexas.edu/pub/ggfc/papers/2013GL056164_preprint.pdf


Extract: "The North Pole has shifted east because of ice sheet loss caused by rising temperatures, a new study published in Geophysical Research Letters has found, according to the scientific journal Nature.
The pole drifted southeast toward northern Labrador, Canada, at a rate of about 6 centimeters per year between 1982 and 2005. But since 2005, the direction and speed of the pole's journey changed. It started moving rapidly east towards Greenland at a rate of more than 21 centimeters per year.
There has been huge ice sheet loss in the polar regions due to global warming.
The study was carried out by scientists from the University of Texas, Austin, using data collected by NASA's Gravity Recovery and Climate Experiment (GRACE).
Earth's two geographic poles do not have a fixed location. As the distribution of snow, rain and humidity changes every year, the poles too wobble around, usually in a circular manner. Besides this seasonal drift, there is a long range movement which scientists believe is driven by continental drift - the movement of land plates relative to each other.
GRACE's twin probes measure changes in the Earth's gravity field, which can be used to track shifts in the distribution of water and ice, Nature said. The researchers led by Jianli Chen, a geophysicist, used GRACE data to model how melting icecaps affect Earth's mass distribution. They found that more than 90% of the post-2005 polar shift was because of increasing ice loss and sea-level rise.
The explanation for this is that when mass is lost in one part of a spinning sphere, its spin axis will tilt directly toward the position of the loss, according to Erik Ivins, a geophysicist at NASA's Jet Propulsion Laboratory in Pasadena, California quoted by Nature. This is exactly what was observed in the case of the North Pole.
These findings have opened the way to estimate long term ice loss by studying polar drift. Scientists can locate the north and south poles to within about 0.9 millimeters by using Global Positioning System measurements to determine the angle of the Earth's spin. Since polar shifts have been recorded for almost a century, Nature says, it is possible to study ice losses for that period. Direct records of ice loss in Polar regions do not go back that much in time."


In the attached images from the article, 1 mas = ~3 cm of polar motion.

[AbruptSLR]

As a follow-on to my last two posts, the linked websites provide information on the acceleration of the migration of the magnetic poles (the image shows the recent migration of the south magnetic pole, see caption.  Note the pole is located in the Southern Ocean):

http://www.ngdc.noaa.gov/geomag/GeomagneticPoles.shtml

http://maps.ngdc.noaa.gov/viewers/historical_declination/

Caption: "Observed south dip poles during 1903 – 2000 are yellow squares. Modeled pole locations from 1590 to 2020 are circles progressing from blue to yellow"

Extract: "It has been long understood that dip poles migrate over time. In 1831, James Clark Ross located the north dip pole position in northern Canada. Natural Resources Canada (NRCan) tracked the North Magnetic Pole, which is slowly drifting across the Canadian Arctic, by periodically carrying out magnetic surveys to reestablish the Pole's location from 1948 to 1994. An international collaboration, led by a French fundraising association, Poly-Arctique, and involving NRCan, Institut de Physique du Globe de Paris and Bureau de Recherche Geologique et Miniere, added two locations of the North Magnetic Pole in 2001 and 2007. The most recent survey determined that the Pole is moving approximately north-northwest at 55 km per year.
…
The magnetic poles or dip pole are computed from all the Gauss coefficients using an iterative method. Magnetic poles derived in this fashion are geographically closer to the experimentally observed poles. Based on the current WMM model, the 2015 location of the north magnetic pole is 86.27°N and 159.18°W and the south magnetic pole is 64.26°S and 136.59°E."

[AbruptSLR]

The linked reference states that: “We find ecologically sensitive regions with amplified responses to climate variability in the Arctic tundra, parts of the boreal forest belt, the tropical rainforest, alpine regions worldwide, steppe and prairie regions of central Asia and North and South America, the Caatinga deciduous forest in eastern South America, and eastern areas of Australia,” (see also the associated image of sensitivity areas).  This study indicates that the key cited vegetation is more sensitivity to climate change (and its associated increasing climate variabilities such as our current Super El Nino) than was previously realized.  Furthermore, the study period from 2000 through 2013, occurred during the faux hiatus and thus may likely have experienced less climate variability than our current phase of postive PDO.  Furthermore, the study underestimated sensitivity due to biological interactions (like bark beetles in coniferous forests and bleaching events in corals):

Alistair W. R. Seddon, Marc Macias-Fauria, Peter R. Long, David Benz & Kathy J. Willis (2016), "Sensitivity of global terrestrial ecosystems to climate variability", Nature, doi:10.1038/nature16986


http://www.nature.com/nature/journal/vaop/ncurrent/full/nature16986.html

Abstract: "The identification of properties that contribute to the persistence and resilience of ecosystems despite climate change constitutes a research priority of global relevance. Here we present a novel, empirical approach to assess the relative sensitivity of ecosystems to climate variability, one property of resilience that builds on theoretical modelling work recognizing that systems closer to critical thresholds respond more sensitively to external perturbations. We develop a new metric, the vegetation sensitivity index, that identifies areas sensitive to climate variability over the past 14 years. The metric uses time series data derived from the moderate-resolution imaging spectroradiometer (MODIS) enhanced vegetation index, and three climatic variables that drive vegetation productivity (air temperature, water availability and cloud cover). Underlying the analysis is an autoregressive modelling approach used to identify climate drivers of vegetation productivity on monthly timescales, in addition to regions with memory effects and reduced response rates to external forcing. We find ecologically sensitive regions with amplified responses to climate variability in the Arctic tundra, parts of the boreal forest belt, the tropical rainforest, alpine regions worldwide, steppe and prairie regions of central Asia and North and South America, the Caatinga deciduous forest in eastern South America, and eastern areas of Australia. Our study provides a quantitative methodology for assessing the relative response rate of ecosystems—be they natural or with a strong anthropogenic signature—to environmental variability, which is the first step towards addressing why some regions appear to be more sensitive than others, and what impact this has on the resilience of ecosystem service provision and human well-being."

See also:
https://www.washingtonpost.com/news/energy-environment/wp/2016/02/17/scientists-just-found-out-where-the-earth-is-most-sensitive-to-climate-swings-and-the-news-isnt-good/

Extract: "“But it  is by definition an underestimate of sensitivity because biological interactions (like bark beetles in coniferous forests and bleaching events in corals) show major ecosystem impacts can occur on top of and as part of vegetation or ecosystem impacts,” Lovejoy said. “All the more reason to limit climate change to 1.5 degrees.”
The research is particularly relevant given the expectation that on top of an overall warming trend, variability in key parts of the climate system could also grow in the future. “It is widely projected that as the planet warms, climate and weather variability will increase. Changes in the frequency and severity of extreme climate events and in the variability of weather patterns will have significant consequences for human and natural systems,” "

[Sigmetnow]

Has Contemporary Academia Outgrown the Carl Sagan Effect?

Sagan’s biographers have argued that the [National Academy of Science's] rejection of Sagan, and Harvard’s prior denial of his tenure, were the direct consequence of the phenomenon that has become known as the “Sagan Effect”: the perception that popular, visible scientists are worse academics than those scientists who do not engage in public discourse.

http://sci-hub.io/downloads/b6af/10.1523@JNEUROSCI.0086-16.2016.pdf

[AbruptSLR]

The linked reference confirms that microbial accelerated permafrost ecosystem respiration exceeds gross primary productivity, resulting in a net positive emission of carbon from the associated soil; which is a positive feedback for global warming that was not included in the AR5 projections:

Kai Xue, Mengting M. Yuan, Zhou J. Shi, Yujia Qin, Ye Deng, Lei Cheng, Liyou Wu, Zhili He, Joy D. Van Nostrand, Rosvel Bracho, Susan Natali, Edward. A. G. Schuur, Chengwei Luo, Konstantinos T. Konstantinidis, Qiong Wang, James R. Cole, James M. Tiedje, Yiqi Luo & Jizhong Zhou (2016), "Tundra soil carbon is vulnerable to rapid microbial decomposition under climate warming", Nature Climate Change, doi:10.1038/nclimate2940


http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2940.html


Abstract: "Microbial decomposition of soil carbon in high-latitude tundra underlain with permafrost is one of the most important, but poorly understood, potential positive feedbacks of greenhouse gas emissions from terrestrial ecosystems into the atmosphere in a warmer world. Using integrated metagenomic technologies, we showed that the microbial functional community structure in the active layer of tundra soil was significantly altered after only 1.5 years of warming, a rapid response demonstrating the high sensitivity of this ecosystem to warming. The abundances of microbial functional genes involved in both aerobic and anaerobic carbon decomposition were also markedly increased by this short-term warming. Consistent with this, ecosystem respiration (Reco) increased up to 38%. In addition, warming enhanced genes involved in nutrient cycling, which very likely contributed to an observed increase (30%) in gross primary productivity (GPP). However, the GPP increase did not offset the extra Reco, resulting in significantly more net carbon loss in warmed plots compared with control plots. Altogether, our results demonstrate the vulnerability of active-layer soil carbon in this permafrost-based tundra ecosystem to climate warming and the importance of microbial communities in mediating such vulnerability."

See also:
https://www.washingtonpost.com/news/energy-environment/wp/2016/02/22/scientists-just-found-yet-another-reason-to-worry-about-arctic-permafrost/

[AbruptSLR]

While I personally have a high regard for scientists in general, including those that contributed to AR5, I find that those who read reports like AR5 have a nasty habit of ignoring almost all of the caveats and hedges contained in such reports, and consequently they communicate rather Pollyannaish views of our current climate change risk profiles.  The linked reference presents one example of this phenomena in that many of the authors of the reference contributed directly to the AR5 carbon budget, and now they issue a report (conveniently published after CoP21) stating that their high end estimates of the post-2015 carbon budget is seriously lower than the AR5 estimates, and that a large share of this reduced margin is associated with meteorological contributions as compared to human activities.  This means that the CoP21 chances of success are lower than publically stated, and that AR6 should adopt tougher carbon budget goals. 

Furthermore, this new updated work also errs on the side of least drama and ignores many nonlinear feedback mechanisms that could accelerate beyond current estimates within the next few decades:

Joeri Rogelj, Michiel Schaeffer, Pierre Friedlingstein, Nathan P. Gillett, Detlef P. van Vuuren, Keywan Riahi, Myles Allen & Reto Knutti (2016), "Differences between carbon budget estimates unraveled", Nature Climate Change, Volume: 6, Pages: 245–252, DOI: 10.1038/NCLIMATE2868

http://www.nature.com/nclimate/journal/v6/n3/full/nclimate2868.html

Abstract: "Several methods exist to estimate the cumulative carbon emissions that would keep global warming to below a given temperature limit. Here we review estimates reported by the IPCC and the recent literature, and discuss the reasons underlying their differences. The most scientifically robust number — the carbon budget for CO2-induced warming only — is also the least relevant for real-world policy. Including all greenhouse gases and using methods based on scenarios that avoid instead of exceed a given temperature limit results in lower carbon budgets. For a >66% chance of limiting warming below the internationally agreed temperature limit of 2 °C relative to pre-industrial levels, the most appropriate carbon budget estimate is 590–1,240 GtCO2 from 2015 onwards. Variations within this range depend on the probability of staying below 2 °C and on end-of-century non-CO2 warming. Current CO2 emissions are about 40 GtCO2 yr−1, and global CO2 emissions thus have to be reduced urgently to keep within a 2 °C-compatible budget."

http://phys.org/news/2016-02-limit-future-climate-emissions.html

Extract: "In a comprehensive new study published in the journal Nature Climate Change, researchers propose a limit to future greenhouse gas emissions—or carbon budget—of 590-1240 billion tons of carbon dioxide from 2015 onwards, as the most appropriate estimate for keeping warming to below 2°C, a temperature target which aims to avoid the most dangerous impacts of climate change.

The study finds that the available budget is on the low end of the spectrum compared to previous estimates—which ranged from 590 to 2390 billion tons of carbon dioxide for the same time period—lending further urgency to the need to address climate change.

"In order to have a reasonable chance of keeping global warming below 2°C, we can only emit a certain amount of carbon dioxide, ever. That's our carbon budget," says IIASA researcher Joeri Rogelj, who led the study. "This has been known for about a decade and the physics behind this concept are well-understood, but many different factors can lead to carbon budgets that are either slightly smaller or slightly larger. We wanted to understand these differences, and provide clarity on the issue for policymakers and the public."

"This study shows that in some cases we have been overestimating the available budget by 50 to more than 200%. At the high end, this is a difference of more than 1000 billion tons of carbon dioxide," says Rogelj.

Estimates for a carbon budget consistent with the 2°C target have varied widely. The new study provides a comprehensive analysis of these differences. The researchers identified that the variation in carbon budgets stemmed from differences in scenarios and methods, and the inclusion of other human activities that can affect the climate, for example the release of other greenhouse gases like methane. Previous research suggested that the varying contribution of other human activities would be the main reason for carbon budget variations, but surprisingly, the study now finds that methodological differences contribute at least as much."

[AbruptSLR]

The linked Robert Scribbler article discusses evidence that Arctic & tropical sources of methane emissions (see attached image) are supplementing the high anthropogenic methane emissions (particularly from China, Russia, the Middle East, Europe, the USA, & India) are contributing to the Earth approaching the 2C limit much faster than the IPCC is forecasting:

http://robertscribbler.com/2016/02/26/2-c-coming-on-faster-than-we-feared-atmospheric-methane-spikes-to-record-3000-parts-per-billion/

Extract: "Here we can see the range of surface methane readings according to Copernicus. A higher resolution image that may provide us with a better idea of the point-source location for daily global methane spikes. Here we see that the major methane sources are predominantly China, Russia, the Middle East, Europe, the United States, India, Indonesia, Fires in Africa and the Amazon, and, finally, the Arctic.
Though the Copernicus measure doesn’t show the same level of Arctic overburden as what has tended to show up in the METOP measure, it’s a confirmation that something in the near Arctic environment is generating local spikes in above 1940 parts per billion for large regions of this sensitive zone.
The Copernicus measure, as noted above, also shows that the human spikes are quite intense, remaining the dominant source of methane emissions globally despite a continued disturbing overburden in the Arctic. Spikes in Africa, the Amazon, and Indonesia also indicate that declining rain forests and related fires in these tropical zones are also probably providing an amplifying feedback to the overall human emission."

[Theta]

http://www.nature.com/ncomms/2016/160209/ncomms10627/full/ncomms10627.html

The linked article talks about how carbon dioxide alone could lead to earth becoming Venus.

[wili]

Maybe even warmer than Venus...perhaps...Venus in Furs??? '-)

Really, we have got to be the most masochistic species ever to have evolved. Of course, sadistic, too.

[Theta]

Maybe even warmer than Venus...perhaps...Venus in Furs??? '-)

Really, we have got to be the most masochistic species ever to have evolved. Of course, sadistic, too.

It's too bad that it's too late for us to change our behaviour

[wili]

It would take an act of imagination that is, perhaps, beyond us at this point--we would have to imagine ourselves back into our actual reality. And that reality is not very pretty, so we will continue to live in the fantasy of an infinite planet even as we continue to trash our all-too-finite, fragile one.

[AbruptSLR]

The linked (open access) reference notes that many AR5 vintage projections did not correctly account for the behavior of permafrost in their soil models. The reference discusses the importance of many of the complex behaviors and interactions (including with precipitation) of permafrost, both with regard to feedback magnitudes (and signs) and seasonal and regional considerations, and how the AR6 generation of climate models need to be improved:

Hagemann, S., Blome, T., Ekici, A., and Beer, C.: Soil frost-induced soil moisture precipitation feedback over high northern latitudes, Earth Syst. Dynam. Discuss., doi:10.5194/esd-2016-5, in review, 2016.

http://www.earth-syst-dynam-discuss.net/esd-2016-5/
http://www.earth-syst-dynam-discuss.net/esd-2016-5/esd-2016-5.pdf

Abstract. Permafrost or perennially frozen ground is an important part of the terrestrial cryosphere; roughly one quarter of Earth's land surface is underlain by permafrost. The impact of the currently observed warming, which is projected to persist during the coming decades due to anthropogenic CO2 input, certainly has effects for the vast permafrost areas of the high northern latitudes. The quantification of these effects, however, is scientifically still an open question. This is partly due to the complexity of the system, where several feedbacks are interacting between land and atmosphere, sometimes counterbalancing each other. Moreover, until recently, many global circulation models (GCMs) and Earth system models (ESMs) lacked the sufficient representation of cold region physical soil processes in their land surface schemes, especially of the effects of freezing and thawing of soil water for both energy and water cycles. Therefore, it will be analysed in the present study how these processes impact large-scale hydrology and climate over northern hemisphere high latitude land areas. For this analysis, the atmosphere-land part of MPI-ESM, ECHAM6-JSBACH, is driven by prescribed observed SST and sea ice in an AMIP2-type setup with and without newly implemented cold region soil processes. Results show a large improvement in the simulated discharge. On one hand this is related to an improved snowmelt peak of runoff due to frozen soil in spring. On the other hand a subsequent reduction of soil moisture leads to a positive land atmosphere feedback to precipitation over the high latitudes, which reduces the model’s wet biases in precipitation and evapotranspiration during the summer. This is noteworthy as soil moisture – atmosphere feedbacks have previously not been in the research focus over the high latitudes. These results point out the importance of high latitude physical processes at the land surface for the regional climate.

[AbruptSLR]

The linked reference identifies a previously unexplored avenue for quantifying the risks and increasing occurrences of extratropical cyclones related to the memory generated by the climate system related to such changes in system states as ocean circulation and sea ice extent (think North Atlantic):

Raible, C. C., D. Stephenson, and G. Leoncini (2016), Predicting the risks and occurrence of extratropical cyclones, Eos, 97, doi:10.1029/2016EO046775.

https://eos.org/meeting-reports/predicting-the-risks-and-occurrence-of-extratropical-cyclones

Extract: "Finally, workshop participants examined the predictability of storms over seasonal and longer time scales. New results suggest a small, yet noticeable, increase in the ability to forecast cyclone-related losses for the North Atlantic European region. Other results discussed showed that the serial clustering of storms within a season is due to the memory generated by the climate system, possibly related to phenomena including ocean circulation and sea ice, although the physical processes have not been firmly established. This serial clustering suggests an unexplored source of predictability."

[wili]

Another Kevin Anderson interview, from when he was in Paris. "The Unforgiving Math for Staying Under 2 Degrees"

[AbruptSLR]

The linked reference both draws attention to a frequently deemphasized source of GHG emissions that result in the terrestrial biosphere acting as a net source of GHG to the atmosphere; while at the same time ESLD with regards to the probable implications of this situation:

Hanqin Tian, Chaoqun Lu, Philippe Ciais, Anna M. Michalak, Josep G. Canadell, Eri Saikawa, Deborah N. Huntzinger, Kevin R. Gurney, Stephen Sitch, Bowen Zhang, Jia Yang, Philippe Bousquet, Lori Bruhwiler, Guangsheng Chen, Edward Dlugokencky, Pierre Friedlingstein, Jerry Melillo, Shufen Pan, Benjamin Poulter, Ronald Prinn, Marielle Saunois, Christopher R. Schwalm & Steven C. Wofsy (10 March 2016), "The terrestrial biosphere as a net source of greenhouse gases to the atmosphere", Nature, Volume: 531, Pages: 225–228, doi:10.1038/nature16946

http://www.nature.com/nature/journal/v531/n7593/full/nature16946.html

Abstract: "The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate1. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change."

[AbruptSLR]

The linked reference indicates that the cloud feedback from tropical land is robustly positive.  As AR5 did not know whether this contribution to climate sensitivity was positive or negative, this clearly indicates that AR5 errs on the side of least drama with regard to both TCR & ECS:

Youichi Kamae, Tomoo Ogura, Masahiro Watanabe, Shang-Ping Xie and Hiroaki Ueda (8 March 2016), "Robust cloud feedback over tropical land in a warming climate", Atmospheres, DOI: 10.1002/2015JD024525

http://onlinelibrary.wiley.com/doi/10.1002/2015JD024525/abstract

Abstract: "Cloud-related radiative perturbations over land in a warming climate are of importance for human health, ecosystem, agriculture and industry via solar radiation availability and local warming amplification. However, robustness and physical mechanisms responsible for the land cloud feedback were not examined sufficiently because of the limited contribution to uncertainty in global climate sensitivity. Here we show that cloud feedback in general circulation models over tropical land is robust, positive, and is relevant to atmospheric circulation change and thermodynamic constraint associated with water vapor availability. In a warming climate, spatial variations in tropospheric warming associated with climatological circulation pattern result in a general weakening of tropical circulation and a dynamic reduction of land cloud during summer monsoon season. Limited increase in availability of water vapor also reduces the land cloud. The reduction of land cloud depends on global-scale oceanic warming and is not sensitive to regional warming patterns. The robust positive feedback can contribute to the warming amplification and drying over tropical land in the future."

[AbruptSLR]

According to the IPCC AR5 report: "The transient climate response is likely in the range of 1.0°C to 2.5°C (high confidence) and extremely unlikely greater than 3°C"; however, the linked reference uses only observed data to indicate that TCR is 2.0 +/- 0.8C.  Thus AR5 has once again erred on the side of least drama.


T. Storelvmo, T. Leirvik, U. Lohmann, P. C. B. Phillips & M. Wild (2016), "Disentangling greenhouse warming and aerosol cooling to reveal Earth’s climate sensitivity", Nature Geoscience, doi:10.1038/ngeo2670


http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2670.html

Abstract: "Earth’s climate sensitivity has long been subject to heated debate and has spurred renewed interest after the latest IPCC assessment report suggested a downward adjustment of its most likely range. Recent observational studies have produced estimates of transient climate sensitivity, that is, the global mean surface temperature increase at the time of CO2 doubling, as low as 1.3 K, well below the best estimate produced by global climate models (1.8 K). Here, we present an observation-based study of the time period 1964 to 2010, which does not rely on climate models. The method incorporates observations of greenhouse gas concentrations, temperature and radiation from approximately 1,300 surface sites into an energy balance framework. Statistical methods commonly applied to economic time series are then used to decompose observed temperature trends into components attributable to changes in greenhouse gas concentrations and surface radiation. We find that surface radiation trends, which have been largely explained by changes in atmospheric aerosol loading, caused a cooling that masked approximately one-third of the continental warming due to increasing greenhouse gas concentrations over the past half-century. In consequence, the method yields a higher transient climate sensitivity (2.0  ±  0.8 K) than other observational studies."


However, I note that Shindell (2014) indicates that it is very unlikely that TCR is less than 1.3C
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140011847.pdf

[Sigmetnow]

I don't know where this is from (other than being from NOAA) -- but it certainly seems worth a share.  Methane growth rate, by latitude and year.

[wili]

So I keep reading reports about how climate scientists are responding to this February peak with words like ‘shocking,’ ‘stunning,’ and just ‘wow.’

I agree, and I know they expected _some_ increases in an El Nino year. But now I want to know what the science didn’t anticipate that has made this monthly peak so high (and I realized that, just as it is difficult to predict the exact effects of GW on a particular place, it is hard to predict what global heat levels will be over just a month’s period).

1) Was it just that the El Nino disgorged even more heat than expected? If so, the timing seems a bit off, since the peak of this El Nino was back in November, iirc. Does it just take that long for the heat to propagate through the system?

2) Was there an additional push from carbon feedbacks starting to kick in? Specifically, there have been recent reports that terrestrial soils, plants and other biological activity are actually a net source of GHGs, rather than a net sink. “when you include the other two main greenhouse gases – methane and nitrous oxide – this completely changes the role of the land in that instead of having a cooling effect on the climate, it has a net warming effect” http://www.azocleantech.com/news.aspx?newsID=23234

It’s not clear to me whether this finding represents mostly a shift in our understanding, or if it also suggests that this shift from sink to source is also a recent development.

3) Are we starting to see the effects of economic slowdown, cleaning up of coal plants, and a general move away from coal on the ‘aerosol umbrella’? Is there some place where they monitor atmospheric aerosols? Has there been a statistically significant change?

4) Is there some other potential cause that I (or possibly even the whole scientific community) have not considered?--miscalculated sensitivity?--bigger than expected albedo shift?...

Of course, it could be some combination of the above, but if so, it would be nice to know how much each contributed, since if 2 and 3 are major factors, we may not see this ‘peak’ drop down quite back to the old linear upward trend (bad as that already was), but rather start on a new, steeper upward trajectory, or it could exhibit a ‘step change.’

Sorry for the multiple questions, but I feel a bit like someone who, somehow conscious during his own brain surgery on what he thought was a serious but minor brain tumor, suddenly hears the surgeon say ‘Wow!’

One rather wants to know something about what is behind that ‘wow,’ and about what it means for the longer term prospects and prognoses.

[Martin Gisser]

So I keep reading reports about how climate scientists are responding to this February peak with words like ‘shocking,’ ‘stunning,’ and just ‘wow.’

According to Tamino (Grant Foster) it is a "Surprise, but not Shock". When correcting for ENSO, solar, volcanic aerosol then what remains is just a rare (ca. decadal for my eyeballs) but unsurprising fluctuation.
https://tamino.wordpress.com/2016/03/13/surprise-but-not-shock/
https://tamino.wordpress.com/2016/03/18/noaa-record-heat-for-february/
https://tamino.wordpress.com/2016/01/29/correcting-for-more-than-just-el-nino/

[AbruptSLR]

wili,
See my responses in bold below:

So I keep reading reports about how climate scientists are responding to this February peak with words like ‘shocking,’ ‘stunning,’ and just ‘wow.’

I agree, and I know they expected _some_ increases in an El Nino year. But now I want to know what the science didn’t anticipate that has made this monthly peak so high (and I realized that, just as it is difficult to predict the exact effects of GW on a particular place, it is hard to predict what global heat levels will be over just a month’s period). Response: Evidently, the "Wow" came from Gavin Schmidt, who likes to err on the side of least drama, and by "Wow" he is expressing sympathy with his boss who is taking political flax because for one (or more likely Feb & March) month(s) we are over the 1.5C "ambitious target" set in December in Paris.  It is always hard to project the future when one insists on erring on the side of least drama because one is always erring.

1) Was it just that the El Nino disgorged even more heat than expected? If so, the timing seems a bit off, since the peak of this El Nino was back in November, iirc. Does it just take that long for the heat to propagate through the system? Response: First, it does take that long for the heat to propagate through the system; but second, 2014-15 was an almost El Nino year so the 2015-16 event was built on-top of an already record high year.

2) Was there an additional push from carbon feedbacks starting to kick in? Specifically, there have been recent reports that terrestrial soils, plants and other biological activity are actually a net source of GHGs, rather than a net sink. “when you include the other two main greenhouse gases – methane and nitrous oxide – this completely changes the role of the land in that instead of having a cooling effect on the climate, it has a net warming effect” Response: the El Nino induced increase in short-term CO2 emission has almost no impact on the current GMST increase; the increased methane and nitrous oxide is probably more anthropogenic forcing (increased meat production for a rich China, fracking, and coal to syngas production) than feedback, and on a 10-year time span methane has a 130 times higher GWP than CO2.  So again must of the surprise is associate with a near El Nino year followed by a Super El Nino year, which might be followed by a near El Nino year [note that global warming increases the frequency of El Nino years and decreases the frequency of La Nina years].
http://www.azocleantech.com/news.aspx?newsID=23234

It’s not clear to me whether this finding represents mostly a shift in our understanding, or if it also suggests that this shift from sink to source is also a recent development.  Response: This mostly represents ESDL behavior where conservative scientists insist on merely straight-lining their projections from the mid-1970's when the US clean air act unmasked the impact of previously accumulated GHG; and now it is possible that the aerosol clean-up in China is unmasking their decades of accumulated GHG (plus methane from their rice & farm animals) which may result in another kink in the trend line that occurred in the mid-1970s (see the attached Tamino-adjusted NOAA curve issued March 18 2016 (hat tip to Martin Gisser).

3) Are we starting to see the effects of economic slowdown, cleaning up of coal plants, and a general move away from coal on the ‘aerosol umbrella’? Is there some place where they monitor atmospheric aerosols? Has there been a statistically significant change?  Response: Yes, the unmasking of the aerosol umbrella is significant, just read my recent posts in the "Aerosol" thread in the Science folder.

4) Is there some other potential cause that I (or possibly even the whole scientific community) have not considered?--miscalculated sensitivity?--bigger than expected albedo shift?...  Response: As I have repeatedly stated (in several hundred posts) climate sensitivity (ECS) is currently one value (not a range) and it is almost certainly significantly higher than AR5 assumes for their 50%CL values; but this is not the cause of the February fluctuation in GMST which is mostly related to the Super El Nino on the back of a near El Nino.

Of course, it could be some combination of the above, but if so, it would be nice to know how much each contributed, since if 2 and 3 are major factors, we may not see this ‘peak’ drop down quite back to the old linear upward trend (bad as that already was), but rather start on a new, steeper upward trajectory, or it could exhibit a ‘step change.’ Response: I believe that: (a) the back to back El Ninos is most important, (b) the reduction in Chinese aerosols is second most important; (c) the recent pulse in atmospheric methane is third most important; and (d) the likely high (but previously masked) ECS is fourth most important.

Sorry for the multiple questions, but I feel a bit like someone who, somehow conscious during his own brain surgery on what he thought was a serious but minor brain tumor, suddenly hears the surgeon say ‘Wow!’  Response: If  scientists like Gavin Schmidt engaged in less ESLD then the "Wow" would not shock you as much [Let the buyer beware].

One rather wants to know something about what is behind that ‘wow,’ and about what it means for the longer term prospects and prognoses.

[Laurent]

linearly exponential...(may be)

[wili]

To paraphrase Gavin, wow!! 

Thanks to Martin and Laurent, and especially to ASLR. More and clearer responses than I deserve!

[AbruptSLR]

To paraphrase Gavin, wow!! 

Thanks to Martin and Laurent, and especially to ASLR. More and clearer responses than I deserve!

wili,

It is a pleasure to respond to your thoughtful questions, but I would like to add that as climate change is a "wicked problem" it is difficult to detangle all of the different contributing factors.  For example, I said that a near El Nino back to back with a Super El Nino was the largest source of the "Wow", but I also believe that the major reason for the increased frequency of El Ninos is that the ECS is relatively high, but its impact has been muted by anthropogenic aerosols, natural aerosols, the recent negative PDO phase; which have all contributed to explain the ESLD AR5 projections.  With a positive PDO, tropical wildfires, reduced anthropogenic aerosol emissions, we see a sharp response that is only the beginning of a gradually building non-linear trend.

Best,
ASLR

[jai mitchell]

To paraphrase Gavin, wow!! 

Thanks to Martin and Laurent, and especially to ASLR. More and clearer responses than I deserve!

wili,

It is a pleasure to respond to your thoughtful questions, but I would like to add that as climate change is a "wicked problem" it is difficult to detangle all of the different contributing factors.  For example, I said that a near El Nino back to back with a Super El Nino was the largest source of the "Wow", but I also believe that the major reason for the increased frequency of El Ninos is that the ECS is relatively high, but its impact has been muted by anthropogenic aerosols, natural aerosols, the recent negative PDO phase; which have all contributed to explain the ESLD AR5 projections.  With a positive PDO, tropical wildfires, reduced anthropogenic aerosol emissions, we see a sharp response that is only the beginning of a gradually building non-linear trend.

Best,
ASLR

in addition to your excellent answers ASLR I wanted to also state that the strong el nino will likely produce significant water vapor feedbacks which is a lagging effect of GHG emissions and aerosol production.  So even the aerosol umbrella removal doesn't produce 100% of total effect until about year 8 after removal, but the El Nino will likely produce lasting warming effect that will be compounded by GHG production and aerosol reduction - as well as likely albedo changes if this year's sea ice melt response is closer to 2007 than 2015.

[AbruptSLR]

Anyone who wants a brief summary on climate change feedback mechanisms they can review the linked information:

https://en.wikipedia.org/wiki/Climate_change_feedback

[AbruptSLR]

The linked (open access) reference indicates that AR5 used inconsistent methodology for calculating the GWP and GTP for methane, and presents consistent methodology:

Ivan Muñoz & Jannick H. Schmidt (22 March 2016), "Methane oxidation, biogenic carbon, and the IPCC’s emission metrics. Proposal for a consistent greenhouse-gas accounting", The International Journal of Life Cycle Assessment, pp 1-7, DOI: 10.1007/s11367-016-1091-z


http://link.springer.com/article/10.1007%2Fs11367-016-1091-z

http://download.springer.com/static/pdf/678/art%253A10.1007%252Fs11367-016-1091-z.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs11367-016-1091-z&token2=exp=1458749264~acl=%2Fstatic%2Fpdf%2F678%2Fart%25253A10.1007%25252Fs11367-016-1091-z.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs11367-016-1091-z*~hmac=3e8b48f8d5b46d57857179a27d3100d64eeb7f0f0e81c3be6a9203734ca9acdf



Abstract: "Purpose
The fifth assessment report by the IPCC includes methane oxidation as an additional indirect effect in the global warming potential (GWP) and global temperature potential (GTP) values for methane. An analysis of the figures provided by the IPCC reveals they lead to different outcomes measured in CO2-eq., depending on whether or not biogenic CO2 emissions are considered neutral. In this article, we discuss this inconsistency and propose a correction.
Methods
We propose a simple framework to account for methane oxidation in GWP and GTP in a way that is independent on the accounting rules for biogenic carbon. An equation with three components is provided to calculate metric values, and its application is tested, together with the original IPCC figures, in a hypothetical example focusing on GWP100.
Results and discussion
The hypothetical example shows that the only set of GWP100 values consistently leading to the same outcome, regardless of how we account for biogenic carbon, is the one proposed in this article. Using the methane GWP100 values from the IPCC report results in conflicting net GHG emissions, thus pointing to an inconsistency.
Conclusions
In order to consistently discriminate between biogenic and fossil methane sources, a difference of 2.75 kg CO2-eq. is needed, which corresponds to the ratio of the molecular weights of CO2 and methane (44/16). We propose to correct the GWP and GTP values for methane accordingly."

[Lennart van der Linde]

New comment by Jim Hansen on dangerous scientific reticence:
http://csas.ei.columbia.edu/2016/03/24/dangerous-scientific-reticence/

'It seems to me that scientific reticence is now greater than when I first wrote on the topic. Do the public, policymakers, and courts understand that scientists use the word “dangerous” with a different meaning than that in the dictionary? Did the Framework Convention not mean the common dictionary definition of the word?'

[Sigmetnow]

How to Talk Global Warming in Plain English
Scientists struggle to convey the risks of climate change simply

In New Orleans, the city’s planners would love to see block-by-block estimates of how sea-level rise might affect neighborhoods and critical infrastructure. In Seattle, they want to know how to shape their municipal culture so that even basic budgeting decisions factor in evolving climate patterns, and not just the past weather patterns that planners have relied on for decades.

Everyone is looking for something different from the next National Climate Assessment, including the scientists and decisionmakers who put together the current guiding document for climate policy in this country. And as they discuss how to put together the next blueprint, they worry about how to best get their message to the people who need most to hear and heed it.

Is anyone reading the assessment? Will anyone read the next one? And how can they make sure that people do?

“If we want to tell the nation the risk, we need to [do it] in plain English,” Alice Hill, the National Security Council’s senior director for resilience policy, told scientists at a gathering in Washington, D.C., last week. As her boss, Susan Rice, often notes, Hill said, “climate change is a dire threat to the prosperity and safety of the American people.”
...
It’s time, many of its past authors say, to consider shifting the assessment away from being a document that tells people what scientists do and do not know about climate change and its risks, and toward something more interactive. Something, many scientists said last week, that explicitly lays out how much time people have to plan, prepare and even pay for the inevitable adaptation.

“We could make the goal that it should change the public discourse,” said Susanne Moser, a California-based scientist who worked on the coastal chapter of the last assessment and who studies ways of helping people understand the challenges and risks of climate change. “Do not tell me just how high the sea-level rise is going to get. Tell me how much time I have to solve a very tough problem.”

http://www.scientificamerican.com/article/how-to-talk-global-warming-in-plain-english/

[AbruptSLR]

Secondary organic aerosols (SOAs) contribute negative radiative forcing to climate change; yet they are almost need accounted for in: (a) paleo-investigations; (b) estimates of climate sensitivity; or (c) climate models.  This implies that if these SOAs were to decrease in the future (say due to deforestation, etc.) the effective climate sensitivity would increase proportionately.  SOAs are formed by chemical reactions in the atmosphere associated with biogenic volatile compounds (BVOCs) including sesquiterpenes.  While sesquiterpenes amount to about 9–29% of the atmospheric concentrations of the better studied monoterpenes, they have not yet received much research.
The linked (open access) reference quantifies the SOA production from sesquiterpenes emissions; and I note that if anthropogenic deforestation and climate change impacts on plants, reduce these and other BVOC emissions, then the effective ECS will increase:

Zhao, Y., Wingen, L. M., Perraud, V., and Finlayson-Pitts, B. J.: Phase, composition, and growth mechanism for secondary organic aerosol from the ozonolysis of α-cedrene, Atmos. Chem. Phys., 16, 3245-3264, doi:10.5194/acp-16-3245-2016, 2016.

http://www.atmos-chem-phys.net/16/3245/2016/

Abstract: "Sesquiterpenes are an important class of biogenic volatile organic compounds (BVOCs) and have a high secondary organic aerosol (SOA) forming potential. However, SOA formation from sesquiterpene oxidation has received less attention compared to other BVOCs such as monoterpenes, and the underlying mechanisms remain poorly understood. In this work, we present a comprehensive experimental investigation of the ozonolysis of α-cedrene both in a glass flow reactor (27–44 s reaction times) and in static Teflon chambers (30–60 min reaction times). The SOA was collected by impaction or filters, followed by analysis using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and electrospray ionization mass spectrometry (ESI-MS), or measured online using direct analysis in real-time mass spectrometry (DART-MS) and aerosol mass spectrometry (AMS). The slow evaporation of 2-ethylhexyl nitrate that was incorporated into the SOA during its formation and growth gives an estimated diffusion coefficient of 3  ×  10−15 cm2 s−1 and shows that SOA is a highly viscous semisolid. Possible structures of four newly observed low molecular weight (MW  ≤  300 Da) reaction products with higher oxygen content than those previously reported were identified. High molecular weight (HMW) products formed in the early stages of the oxidation have structures consistent with aldol condensation products, peroxyhemiacetals, and esters. The size-dependent distributions of HMW products in the SOA, as well as the effects of stabilized Criegee intermediate (SCI) scavengers on HMW products and particle formation, confirm that HMW products and reactions of SCI play a crucial role in early stages of particle formation. Our studies provide new insights into mechanisms of SOA formation and growth in α-cedrene ozonolysis and the important role of sesquiterpenes in new particle formation as suggested by field measurements."

[AbruptSLR]

The following abstract discusses recent efforts in Norway to better understand the implications of BVOC-SOA-cloud-climate feedbacks.  Such studies focus on recent measurements, and as in recent times both global warming and increased atmospheric CO₂ concentrations have stimulated BVOC emissions; such studies tend to downplay the risks of future reductions in SOA concentrations.  Nevertheless, the risks are real, but the magnitude of such risks is still being debated:

Kari Alterskjær, Jon Egill Kristjansson, Alf Grini, Trond Iversen, Alf Kirkevåg, Dirk Olivié, Michael Schulz, and Øyvind Seland (2016), "Investigations of BVOC-SOA-cloud-climate feedbacks via interactive biogenic emissions using NorESM", Geophysical Research Abstracts, Vol. 18, EGU2016-12547-1

http://meetingorganizer.copernicus.org/EGU2016/EGU2016-12547-1.pdf

Abstract: "Climate feedbacks represent a large source of uncertainty in future climate projections. One such feedback involves a change in emissions of biogenic volatile organic compounds (BVOCs) under global warming and a subsequent change in cloud radiative effects. Parts of the atmospheric BVOCs will oxidize in the atmosphere, which may reduce their volatility enough to form secondary organic aerosols (SOA). A changed SOA load will affect cloud radiative properties through aerosol-cloud interactions (ACI) and therefore act to reduce or enhance the temperature change resulting from greenhouse gases alone. In order to study this effect, a development version of the Norwegian Earth System Model (NorESM) has been extended to include explicit atmospheric particle nucleation and a treatment of SOA based on work by Risto Makkonen and collaborators. Biogenic sources of monoterpene and isoprene are interactively calculated by the Model of Emissions of Gases and Aerosols from Nature (MEGAN), version 2.1, incorporated into the Community Land Model, version 4.5. Monoterpene and isoprene are oxidized by O3, OH and NO3 to form SOA with a yield of 15 % and 5 % respectively. It is assumed that 50 % of the product from monoterpene ozonolysis is of low enough volatility to nucleate new particles. The remaining oxidized BVOCs condensate onto preexisting particles. The model improvements include three new tracers to account for both SOA and the BVOCs. This allows for transport of both SOA and precursor gases, making it possible for SOA to form above the surface layer of the model. The new SOA treatment also changes the size distribution of most model aerosols due to condensation.  Preliminary results from 6-year simulations with prescribed sea surface temperatures show that the present day emissions of both isoprene (435.9 Tg/yr) and monoterpenes (121.4 Tg/yr) are within the range found in other studies. The resulting SOA production is on the order of 77 Tg/yr, also within the range found by others, but on the high side. The global annual atmospheric burden of SOA is on the order of 1.0 Tg. A fraction of 4.5% of the produced SOA is nucleated into particles, while the remainder forms condensate. In the current set-up, emissions of both monoterpene and isoprene are slightly higher pre-industrially than in present day, which seems to be due to large land use changes. In regions of small land use changes, the change in 2 m air temperature dominates, with high air temperatures corresponding to high BVOC emissions. An estimate will be made of the change in cloud radiative properties from pre-industrial times to present caused by the change in BVOC emissions and resulting change in SOA burden."

[Richard Rathbone]

New comment by Jim Hansen on dangerous scientific reticence:
http://csas.ei.columbia.edu/2016/03/24/dangerous-scientific-reticence/

'It seems to me that scientific reticence is now greater than when I first wrote on the topic. Do the public, policymakers, and courts understand that scientists use the word “dangerous” with a different meaning than that in the dictionary? Did the Framework Convention not mean the common dictionary definition of the word?'

Hansen's talking bollocks* here, and he really ought to know it. Dangerous has a whole slew of meanings which are easily confused in the public mind. (They are easily confused in the minds of professionals too, which is why risk assessment requires formal processes.) Specifically it relates to both the severity and probability of outcomes and the manner in which Hansen was trying to use it is confusing an undeniably severe outcome with a dubiously probably one.

*a term which the general public might be expected to understand but probably should not be used in the title of a scientific paper, because while everybody has an idea of what talking bollocks is, these ideas are unlikely to be congruent across the general spectrum of opinion.

[AbruptSLR]

New comment by Jim Hansen on dangerous scientific reticence:
http://csas.ei.columbia.edu/2016/03/24/dangerous-scientific-reticence/

'It seems to me that scientific reticence is now greater than when I first wrote on the topic. Do the public, policymakers, and courts understand that scientists use the word “dangerous” with a different meaning than that in the dictionary? Did the Framework Convention not mean the common dictionary definition of the word?'

Hansen's talking bollocks* here, and he really ought to know it. Dangerous has a whole slew of meanings which are easily confused in the public mind. (They are easily confused in the minds of professionals too, which is why risk assessment requires formal processes.) Specifically it relates to both the severity and probability of outcomes and the manner in which Hansen was trying to use it is confusing an undeniably severe outcome with a dubiously probably one.

*a term which the general public might be expected to understand but probably should not be used in the title of a scientific paper, because while everybody has an idea of what talking bollocks is, these ideas are unlikely to be congruent across the general spectrum of opinion.

The title of Hansen et al (2016) is: "Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 C global
warming could be dangerous". 

The very clear use of the phrase "could be dangerous" in the title means that the public understands that there is uncertainty involved.

[Sigmetnow]

Time Magazine Got Global Warming Right In 2006: ‘Be Worried. Be Very Worried’
By Joe Romm

Let’s be very clear that 10 years ago, anyone who spent a lot of time talking to leading climate scientists would have become “very worried” about what was likely to happen on the business-as-usual path of CO2 emissions. I did. That’s why I titled the book I wrote in 2006 “Hell and High Water” — and that’s why I launched this blog that same year.

The main differences in climate science between now and 10 years ago are:

- Until the last year or two, emissions were tracking at the very highest end of what scientists had projected they would
- Many of the most worrisome impacts have happened at a faster pace than climate scientists had expected
- Most of the worst fears of climate scientists in 2006 are now part of the published peer-reviewed literature — and the worst fears of climate scientists today are beyond alarming

So people should be even more worried today — and they are! That’s why more and more leading climate scientists have become uncharacteristically blunt and why dozens of them told the world’s governments last year that we have to stay as far below 2°C as possible — preferably 1.5°C. And it’s why the world’s leading governments unanimously pledged to do just that in Paris in December.

Unfortunately, the amount of worry-generated climate action today — while vastly greater than the amount 10 years ago — is still lagging far behind the science. Beating 2°C requires a World War II-scale effort sustained for decades.

http://thinkprogress.org/climate/2016/03/29/3764068/time-global-warming-worried/

[AbruptSLR]

The linked article discusses some of the risks of climate change to the world's microbiomes:

http://e360.yale.edu/feature/is_climate_change_putting_world_microbiomes_at_risk/2977/

Extract: "Most urgent, though, is the fact that the earth has locked up a great deal of carbon and should it come unlocked as C02 it could dramatically speed up climate change. "The big question is whether soil will be a sink or source of greenhouse gases in the future," said Jansson.

One of the major areas of study is a feedback loop — the impact of climate change on microbes, and the role of microbes in climate change. Soil microbes are key players in how much greenhouse gas permafrost releases into the atmosphere, and it’s probably the most critical area of study. The frozen vegetation, rich in microorganisms, is thawing as the Arctic warms rapidly and microbes consume the newly available plant matter and release both C02 and methane, potent greenhouse gases.

…

It's not just permafrost. All soil contains large stores of CO2, and scientists are trying to understand how climate change will impact those stores, and how they could be released by land management practices. Much of this information will help create more accurate models of global climate change. And it will also provide insight into ways to alter land management practices to minimize the amount of CO2 released from soil. Tillage and desertification, for example, unlock greenhouse gases in the soil and allow them into the atmosphere. "There are certain soils that just dragging a plow through it displaces huge, huge quantities of carbon," said Bailey. No-till farming, which leaves residue from past crops on the soil and minimizes plowing, is far more beneficial because it gives the microbes food and shelter."

[jai mitchell]

A 2015 howarth paper http://www.eeb.cornell.edu/howarth/publications/f_EECT-61539-perspectives-on-air-emissions-of-methane-and-climatic-warmin_100815_27470.pdf showed that methane fugitive leakage from conventional sources was 3.6% and from shale sources (natural gas + tight oil) was 12%.  Since shale sources are 47% of total u.s. production this means that in 2015 the total U.S. annual fugitive leakage rate was 7.6%

This recent study by Zhang et. al. http://www.sciencedirect.com/science/article/pii/S030626191501243X shows that the most efficient natural gas power plant with a 4% leak rate is equivalent to a coal-fired power plant on a 90-year timeline with some extra warming between years 50-90.

In the supplemental data other leak rates were shown, the highest being 6%.  From the graphic below, it can be inferred that U.S. natural gas combined cycle electric power generation is worse than coal until year 60, with a period of year 0-45 where it is much worse than coal.

[Laurent]

Climate Models May Overstate Clouds’ Cooling Power, Research Says
http://www.nytimes.com/2016/04/08/science/climate-models-may-overstate-clouds-cooling-power-research-says.html?smid=fb-share&_r=0

The computer models that predict climate change may be overestimating the cooling power of clouds, new research suggests. If the findings are borne out by further research, it suggests that making progress against global warming will be even harder.

[AbruptSLR]

Climate Models May Overstate Clouds’ Cooling Power, Research Says
http://www.nytimes.com/2016/04/08/science/climate-models-may-overstate-clouds-cooling-power-research-says.html?smid=fb-share&_r=0

The computer models that predict climate change may be overestimating the cooling power of clouds, new research suggests. If the findings are borne out by further research, it suggests that making progress against global warming will be even harder.

Here is a full citation for the reference that Laurent discussed.  If Tan et al (2016) is correct that ECS may well be between 5.0 and 5.3C then "happy talk" people like Gavin Schmidt should be pushed aside from their current jobs and replace by more serious scientists.

Ivy Tan, Trude Storelvmo & Mark D. Zelinka (08 Apr 2016), "Observational constraints on mixed-phase clouds imply higher climate sensitivity", Science, Vol. 352, Issue 6282, pp. 224-227, DOI: 10.1126/science.aad5300


http://science.sciencemag.org/content/352/6282/224

Significance: "How much global average temperature eventually will rise depends on the Equilibrium Climate Sensitivity (ECS), which relates atmospheric CO2 concentration to atmospheric temperature. For decades, ECS has been estimated to be between 2.0° and 4.6°C, with much of that uncertainty owing to the difficulty of establishing the effects of clouds on Earth's energy budget. Tan et al. used satellite observations to constrain the radiative impact of mixed phase clouds. They conclude that ECS could be between 5.0° and 5.3°C—higher than suggested by most global climate models."

Abstract: "Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations. The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate. We point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback."

See also:

http://www.climatecentral.org/news/clouds-play-lesser-role-in-curbing-warming-20221

Extract: "Tan, meanwhile, said it would be a mistake to focus too closely on the exact number. The sensitivity result from the modeling experiments should be taken “with a grain of salt,” she said.

That’s because the study was based on a single model. A main point in conducting the experiments was to show that climate models contain a bias that could be corrected. The group hopes other scientists will conduct similar experiments using different models to help hone in on a more reliable measure of climate sensitivity.

Michael Mann, a meteorology professor at Penn State who was not involved with the study, said it’s “speculative” but “plausible” that global climate models have been underestimating climate sensitivity by assuming too much cloud glaciation."

[AbruptSLR]

The linked article elaborates on Tan et al (2016) and expresses hope that the AR6 climate models correct the AR5 underestimate of positive cloud feedback:

http://news.yale.edu/2016/04/07/climate-models-have-underestimated-earth-s-sensitivity-co2-changes-study-finds


Extract: "“The overestimate of ice in mixed-phase clouds relative to the observations is something that many climate modelers are starting to realize,” Tan said.

The researchers also stressed that correcting the ice-water ratio in global models is critical, leading up to the IPCC’s next assessment report, expected in 2020."

[AbruptSLR]

The linked article provides even more perspective on the Tan et al (2016) paper on cloud feedback; indicating that more work is needed before AR6 models adopt such a strong positive cloud feedback mechanism:


http://www.theguardian.com/environment/2016/apr/07/clouds-climate-change-analysis-liquid-ice-global-warming

Extract: "… Dr Kevin Trenberth, senior scientist at the National Center for Atmospheric Research, said research has already shown “major errors in climate simulations associated with clouds”.
Trenberth said there is “some art” to working out the role of clouds, given their annual cycles and distribution, with uncertainty over whether climate sensitivity is significantly changed.
“I think the paper is fine as a first step but it is not the last step, and much more is needed to establish how clouds change as the climate changes,” Trenberth said of the Yale study."

[AbruptSLR]

The linked article offers more insights on the Tan et al (2016) reference:

http://www.csmonitor.com/Science/2016/0408/Global-warming-Clouds-may-be-less-helpful-than-we-thought

Extract: "The more liquid water a cloud contains, the better it is at reflecting solar radiation back into space, helping to keep the Earth cool by preventing the sun's rays from ever hitting the surface. So, as our atmospheric temperatures rise, and the ice in mixed-phase clouds melts, those clouds become more reflective, in what represents a negative feedback loop for global temperature.
In other words, the more ice the clouds have in them, the stronger the buffer they are against global warming. What this study found was that climate models have overestimated the amount of ice in our clouds, meaning there is less available to melt and offset temperature rises.
"It’s really in the last couple of years that this problem has been identified in the models," says Dr. Storelvmo, "and it's because of the new instruments available on CALIPSO."

...

The actual numbers are up for debate, but there does seem to be fairly broad acceptance in the scientific community as to the fundamentals of the work’s conclusions, as Michael Mann, distinguished professor of atmospheric science at Pennsylvania State University, explains to the Monitor.

"I find the paper reasonably compelling that shortcomings in how certain key cloud processes are treated could well be leading to an overestimation of the ability of cloud feedbacks to ameliorate global warming," says Dr. Mann in an e-mail interview. "There is indeed other recent work that makes a similar case.""

[AbruptSLR]

In the linked article Robert Scribbler discusses the Hansen et al (2016) findings (see extract and the attached nullschool image showing the size of the April 8 2016 cool spot in the North Atlantic):

https://robertscribbler.com/2016/04/08/early-warning-signs-for-james-hansens-superstorms-visible-north-atlantic-cool-pool-as-harbinger-to-all-hell-breaking-loose/

Extract: "What we risk, and what Hansen has warned us about in what he considers to be his most important work of science, is setting off a severe chain of events that includes rapid sea level rise and powerful, powerful storms. In addition, the ocean stratification that is the cause of all this atmospheric and oceanic trouble would set off further consequences not touched on in Hansen’s work — hitting ocean health hard and, likely, liberating more carbon stores from the Earth System to add to the troubles that humans are already rapidly bringing to the fore.
One final point — the Hansen paper has and will continue to generate a huge controversy in the science. But from the point of view of this threat analyst, there is a high potential for dangerous outcomes similar to those the Hansen paper warms of together with a number of additional troubles so long as the human-forced warming continues. And we already see visible evidence of those kinds of dangerous atmospheric and ocean changes starting to happen now."

[AbruptSLR]

Regarding Tan et al (2016), I thought that I would point out that the mixed-phase cloud positive feedback mechanism that they identified increased their model ECS value by about 25%; which indicates that before they applied their newly identified cloud feedback mechanism their model's ECS was between 4C and 4.15C; which is closely inline with the value that Sherwood found; which emphasized that different cloud feedback mechanisms are additive.

[AbruptSLR]

Regarding Tan et al (2016), I thought that I would point out that the mixed-phase cloud positive feedback mechanism that they identified increased their model ECS value by about 25%; which indicates that before they applied their newly identified cloud feedback mechanism their model's ECS was between 4C and 4.15C; which is closely inline with the value that Sherwood found; which emphasized that different cloud feedback mechanisms are additive.

The title of the linked article is "Why Uncertainty About Climate Change is Not Our Friend"; and the following extract illustrates what climate change is a "wicked problem" as there are so many different positive and negative feedback mechanisms it is difficult exactly how much of each different mechanism to put into a non-linear climate model in order to both match the observed record and to reasonably accurately forecast future conditions with radiative forcing many times higher than the Earth has experienced for over a billion years.  That said, it is very simple minded for "happy talk" scientists like Gavin Schmidt to assume the simplest forcing combination with the lowest ECS is the most likely case.  Uncertainty is not our friend and serious climate scientists need to publish upper bound projections; otherwise, policy makers will surely say that they were not adequately warned and "Who Would Have Thought?".

www.washingtonpost.com/news/energy-environment/wp/2016/04/07/why-uncertainty-about-climate-change-is-not-our-friend/

Extract: "The research is “a great example of the use of state-of-the-art satellite retrievals to constrain climate model process simulations, and this emerging constraint points towards a positive rather than a negative cloud brightness feedback and towards a higher climate sensitivity,” said George Tselioudis, a NASA climate expert who studies clouds and climate models, by email.

However, Anthony Del Genio, another NASA expert, was a bit more skeptical, noting that satellites may observe one thing on the outside of clouds, but that doesn’t mean what’s happening on the inside of them is the same. He also said that generally, the key processes involved are just very difficult for scientists to observe. “It is easy to say that climate models should fix this problem. But in practice it’s hard to fix because we don’t have the necessary data,” he said by email.

It is probably premature, then, to say that the new research means that scientists as a whole will now be concluding that thanks to a better understanding of clouds, the Earth is more sensitive to carbon dioxide than we thought — and will likely warm more than expected, or, at the high range of what’s currently expected. It’s rare that one study has such a sweeping impact.

“Headlines that scream ‘Scientists say sensitivity higher than thought!’ will not be justified,” says Gavin Schmidt, who directs NASA’s Goddard Institute for Space Studies. “This is one extra ingredient that needs to go into the hopper.”

Still, the new study clearly underscores that, while we don’t know everything about the climate yet, the things we don’t know could just as well harm us as help us.

“Our study suggests that the climate sensitivity range should be shifted upwards,” says Tan. “By how much, we don’t know exactly.”"