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Messages - jai mitchell

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Science / Re: Radiative forcing and CO2eq
« on: Today at 06:38:31 AM »
Well, nobody really needs the concept of CO2e -- one can just sum up the forcings and leave it at that, in W m-2, rather than fake CO2 ppmv. 

Understanding effective radiative forcing is a good idea as expressed in the linked reference that provides a summary of the latest IPCC thinking on anthropogenic aerosols & their impact on global climate.  The reference states: "From 1850 to 2010, anthropogenic aerosols brought about a decrease of ∼2.53 K and ∼0.20 mm day−1 in global annual mean surface temperature and precipitation, respectively."  Therefore, as we are already over a +1C value of GMSTA, if we dropped back to 1850 levels of aerosols we might increase GMSTA to over +3.5C, even if we dropped to zero emissions of CO2 by switching 100% to solar & wind power today:

Hua Zhang, Shuyun Zhao, Zhili Wang, Xiaoye Zhang & Lianchun Song (25 January 2016), "The updated effective radiative forcing of major anthropogenic aerosols and their effects on global climate at present and in the future", International Journal of Climatology, DOI: 10.1002/joc.4613

Abstract: "The effective radiative forcing (ERF), as newly defined in the Intergovernmental Panel on Climate Change's Fifth Assessment Report (IPCC AR5), of three anthropogenic aerosols [sulphate (SF), black carbon (BC), and organic carbon (OC)] and their comprehensive climatic effects were simulated and discussed, using the updated aerosol-climate online model of BCC_AGCM2.0.1_CUACE/Aero. From 1850 to 2010, the total ERF of these anthropogenic aerosols was −2.49 W m−2, of which the aerosol–radiation interactive ERF (ERFari) and aerosol–cloud interactive ERF (ERFaci) were ∼ −0.30 and −2.19 W m−2, respectively. SF was the largest contributor to the total ERF, with an ERF of −2.37 W m−2. The ERF of BC and OC were 0.12 and −0.31 W m−2, respectively. From 1850 to 2010, anthropogenic aerosols brought about a decrease of ∼2.53 K and ∼0.20 mm day−1 in global annual mean surface temperature and precipitation, respectively. Surface cooling was most obvious over mid- and high latitudes in the northern hemisphere (NH). Precipitation change was most pronounced near the equator, with decreased and increased rainfall to the north and south of the equator, respectively; this might be largely related to the enhanced Hadley Cell in the NH. Relative humidity near surface was increased, especially over land, due to surface cooling induced by anthropogenic aerosols. Cloud cover and water path were increased, especially in or near the source regions of anthropogenic aerosols. Experiments based on the Representative Concentration Pathway (RCP) 4.5 given in IPCC AR5 shows the dramatic decrease in three anthropogenic aerosols in 2100 will lead to an increase of ∼2.06 K and 0.16 mm day−1 in global annual mean surface temperature and precipitation, respectively, compared with those in 2010."

My god, I forgot about that.  Wasn't that paper somewhat challenged by the climate scientific body, I mean ascribing a 2C increase SOLELY to the removal of SO2 from our emission profile and adding that to the current warming ~1.1C AND locked-in warming from current GHG forcing ~0.6C AND future warming from carbon cycle feedbacks ~1.3C by 2100 (this is a very low estimate) would mean that we have already locked in a +5.0C world at today's GHG levels!

Talk me down ASLR!!!! IMA bout 2 jump. . .

Science / Re: Radiative forcing and CO2eq
« on: Today at 06:32:41 AM »
There is a lot of uncertainty in these estimates.  Faster reduction in aerosols would increase the rate of warming, while faster reduction in ozone would decrease warming.

Those are great graphics. 

There is a lot of uncertainty in the emissions rates going forward but there is even MORE uncertainty in the total forcing impact of SO2, including impacts on cloud physics and on the ENSO and AMO. 

Policy and solutions / Re: Solar Roadways
« on: Today at 06:24:18 AM »
Dave, most excellent and enthusiastic video blogger, trustworthy source on all things electronic:

more than a little disingenuous to compare metered values from the Netherlands when looking at potential installation in Arizona (Arizona gets more than twice as much annual sunshine)

Consequences / Re: Hurricane season 2017
« on: Today at 06:17:11 AM »
what the HELL is Jose doing?  Waiting in the wings for Maria to come up so that they can do the Fujiwhara shuffle???,33.15,1879/loc=-73.047,25.250

I am at a total loss at this, it just doesn't feel right. 

I guess the biggest issue is, how accurate can the models be now that we have hurricanes jumping 2 categories above model projections in only 24 hours and a stationary hurricane off of the New England coastline???

Seriously, long range forecasts show Jose doing ANOTHER loop and possibly moving west with a major hurricane Maria moving into the U.S. south. . . it baffles the mind. . .

Science / Re: Radiative forcing and CO2eq
« on: September 17, 2017, 11:06:10 PM »
It should also be noted that the NOAA AGGI value that matches yours also does not include increased water vapor or other feedbacks in their estimation of comparative total forcing. 

Did you include these values in your total anthropogenic CO2eq?
Those are feedbacks, not forcings.  Forcings are used as inputs to the models, while feedbacks are represented by processes within the models.

To be clear, the models used to develop NOAA AGGI CO2eq forcing values do NOT include feedbacks that result from GCM model outputs.  However, we do have good satellite records of recent atmospheric water vapor increases and their additional forcing values can be extracted (with high uncertainty in comparison to 1750 values).

Science / Re: Radiative forcing and CO2eq
« on: September 17, 2017, 03:49:24 PM »
It should also be noted that the NOAA AGGI value that matches yours also does not include increased water vapor or other feedbacks in their estimation of comparative total forcing. 

Did you include these values in your total anthropogenic CO2eq?

Science / Re: Radiative forcing and CO2eq
« on: September 17, 2017, 03:19:22 PM »
Isaksen also followed up the above 2011 paper with a 2014 paper that looked specifically at the impacts of increased emissions of CH4 from transportation and the Arctic in future years, as well as the climate feedbacks of increased Ozone production in a warming world.  see paper here:

The chemistry balance shifts of Stratospheric water vapor and Ozone, and their increased forcing potentials are shown in table 2 and below.

Most concerning to me is the translation of the increased radiative forcing of Methane, and the resultant increase in tropopause heights as an additional warming feedback on the evaluation of Global Warming Potential of these short-lived climate pollutants.  If applied as an equal adjustment for both the GWP-100 and the GWP-20 then the adjusted multiplier of CO2e for methane under GWP-100 (35) and GWP-20 (105) increase to (37.4) and (112.1) respectively, and if emissions rates of CH4 are held constant over time.

However, since CH4 only exists in the upper atmosphere for 10-12 years, the relative impacts from this gas are front-loaded and since this front-loading results in a ~7% increased RF on the 100-year GWP then it stands to reason that under a shift to GWP-20 this effect would increase at a much higher rate than the GWP-100 value.

This very complex atmospheric chemistry issue, under varying climate conditions, requires updated inputs into complex chemistry transport models and GCMs to winnow out the total warming impacts.

note: an excellent reference describing these chemistry interactions from Daniel Jacobs' Introduction to Atmospheric Chemistry - 1999 Can be found here:

full online book here:

Science / Re: Radiative forcing and CO2eq
« on: September 17, 2017, 05:56:59 AM »
Using all anthropogenic forcings (from here) the CO2eq values are approximately 422 ppmv (old) and 432 ppmv (new).

Thanks for your response and your work this looks very interesting, The NOAA AGGI CO2eq for 2016 is calculated to be (see: ) 489 ppm. 

From their methodology paper here:

See table 2, the values you have come up to theirs quite well 2016 CO2e

Science / Re: Radiative forcing and CO2eq
« on: September 16, 2017, 06:08:11 PM »
Since Etminan 2016 states the 2011 differential value of forcing for CH4 to be +0.13, and you have previously stated that this value is too high, please post your "previous" and "new" values for CH4 for the year 2011.  If it is less (or more!) than 0.13 Watts per meter squared then your calculation is off.

Note that the relative values is not important here, only the differential, since you are using a different baseline than he does (1750).

I understand you are only looking at the "big three" (CO2, CH4 and NO2) so when you post your CO2eq values you need to note that you are excluding the additional forcing from O3 (0.4 W/m^2) and trace GHGs (0.339 W/m^2).  This additional forcing (using the pre-Etminan values produces a real CO2eq value of 526.6 ppmv The additional forcing of Etminan increases this value somewhat.

Consequences / Re: Hurricane season 2017
« on: September 16, 2017, 12:26:00 AM »
Disturbance 1 looks very significant in the Caribbean (and on toward Florida) on the long-range models, Hurricane Jose looks to be more than insignificant with wind-speed and storm surge damage to New England.,27.91,818/loc=-162.147,14.467

Consequences / Re: Hurricane season 2017
« on: September 16, 2017, 12:22:51 AM »
. . . and then it will be too late anyway.

Talk about not helping.   It is a simple fact of human nature that we are basically herd animals who need to see concrete physical action or threat to get behind something.  In the absence of a rational, moral and representational government who has effectively denied climate change and its threats for the last 30 years, It will likely take continued impacts, coupled with local-scale movements eventually catalyzing into a national-scale movement, like occupy wall street, before our government actually does the hard work of saying 'NO' to their wealthy fossil-fuel interest donors and lobbyists.

Science / Re: Carbon Cycle
« on: September 14, 2017, 05:18:44 PM »
The linked reference shows that CO2 emissions from boreal lakes has been severely underestimated, this study doubles the rate of CO2 from boreal lakes.  The increase of surface area of boreal lakes is a primary feature of arctic amplification vis-a-vis permafrost melt.

CO2 evasion from boreal lakes: revised estimate, drivers of spatial variability, and future projections


Lakes (including reservoirs) are an important component of the global carbon (C) cycle, as acknowledged by the 5th assessment report of the IPCC. In the context of lakes, the boreal region is disproportionately important contributing to 27% of the worldwide lake area, despite representing just 14% of global land surface area. In this study, we used a statistical approach to derive a prediction equation for the partial pressure of CO2 (pCO2) in lakes as a function of lake area, terrestrial net primary productivity (NPP) and precipitation (r2 = 0.56), and to create the first high resolution, circumboreal map (0.5) of lake pCO2. The map of pCO2 was combined with lake area from the recently published GLOWABO database and three different estimates of the gas transfer velocity k to produce a resulting map of CO2 evasion (FCO2). For the boreal region we estimate an average, lake area weighted,pCO2 of 966 (678- 1325) μatm and a total FCO2 of 189 (74-347) Tg C yr−1, and evaluate the corresponding uncertainties based on Monte Carlo simulation. Our estimate of FCO2 is approximately twofold greater than previous estimates, as a result of methodological and data source differences. We use our results along with published estimates of the other C fluxes through inland waters to derive a C budget for the boreal region, and find that FCO2 from lakes is the most significant flux of the land-ocean aquatic continuum, and of a similar magnitude as emissions from forest fires. Using the model and applying it to spatially resolved projections of terrestrial NPP and precipitation while keeping everything else constant, we predict a 107% increase in boreal lake FCO2 under emission scenario RCP8.5 by 2100. Our projections are largely driven by increases in terrestrial NPP over the same period, showing the very close connection between the terrestrial and aquatic C cycle.

Consequences / Re: Hurricane season 2017
« on: September 06, 2017, 10:02:14 PM »
St. Martin video of storm from remotely operated camera. . .what planet is this???

Consequences / Re: Hurricane season 2017
« on: September 06, 2017, 09:43:49 PM »
modeled track for Katia is South and East

Consequences / Re: Hurricane season 2017
« on: September 06, 2017, 08:50:19 PM »
article published 30 minutes ago.

Hurricane Irma UPDATE: Barbuda diplomat says ALL CONTACT has been lost with island

HURRICANE IRMA has interrupted all communications between the Caribbean island of Barbuda with nearby islands after concerning reports recorded devastating consequences on local buildings.

Karen-Mae Hill, Antigua and Barbuda's High Commissioner,  told Sky News all contact with the island was lost shortly after midnight.

She said: "We have not been able to make any contact with Barbuda since about midnight UK time.

"The last report we had from our sister island was the police station was destroyed, the roof came off completely. Houses all around Codrington, the main settlement on Barbuda, have lost their roofs.

Consequences / Re: Hurricane season 2017
« on: September 06, 2017, 08:02:35 PM »
CNN reports that 6 hours after a direct hit to the tiny island of Barbuda no one has yet heard from them. . .

Arctic sea ice / Re: Latest PIOMAS update (September update)
« on: September 06, 2017, 05:53:57 PM »
PIOMAS updated, both the official volume numbers and the gridded data.

I updated my volume graphics, can be seen in the top post

what a shocking turnaround from April!!!

Consequences / Re: Conservative Scientists & its Consequences
« on: September 06, 2017, 05:52:30 PM »
with no climate mitigation, boreal CH4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH4 feedbacks to maintain average global warming below 2 °C."

Those Boreal estimates seem low by about 10X (by 2099) under RCP 8.5  The wetlands CH4 seems high, as changes in precipitation regimes in current peat and rainforest locations should lead to significant drying and fire, not increased CH4 production. 

Consequences / Re: Hurricane season 2017
« on: September 06, 2017, 03:38:25 AM »

Pressure down to 916...which should correspond to sustained winds at around 225 mph! But official wind speed is still 185. Thoughts?

Hurricane is passing through a very favorable region of pressure gradient in the upper atmosphere, this somewhat inflates the difference in the central pressure drop.  At least that is what some guy on the internet said. . . but I expect it to continue to intensify.  Models had central pressure going below 900 mb.

Consequences / Re: Hurricane season 2017
« on: September 06, 2017, 12:56:13 AM »
null school is showing a worst-case miami scenario with cat 4 wind speeds for a few hours


9.6 meter wave height (not including storm surge estimated to be 7-12 feet),27.58,3000/loc=-79.943,26.220

Edit: not sure now, this looks to be much bigger than current wave heights so maybe it does include storm surge of up to 3 meters.

Consequences / Re: Hurricane season 2017
« on: September 05, 2017, 08:00:55 PM »
Central Pressure 926 sustained maximum wind speeds 185 mph

from the weather channel twitter:

Consequences / Re: Hurricane season 2017
« on: September 05, 2017, 06:44:37 PM »
Central Pressure Irma measured at 927mb

Consequences / Re: Hurricane season 2017
« on: September 04, 2017, 01:52:33 AM »
Or is this already one of Hansen's "storms of my grandchildren"?

too soon.

Consequences / Re: Conservative Scientists & its Consequences
« on: September 03, 2017, 07:30:47 PM »
this one will be very useful

Combining observations and models to reduce uncertainty in the cloud response to global warming (258995)
Joel R Norris, University of California San Diego, La Jolla, CA, United States, Timothy Myers, University of California Los Angeles, Los Angeles, CA, United States and Seethala Chellappan, Scripps Institution of Oceanography, La Jolla, CA, United States

Consequences / Re: Hurricane season 2017
« on: September 03, 2017, 07:22:15 PM »
this video has a good description of the high pressure steering ridge.

Consequences / Re: Hurricane season 2017
« on: September 03, 2017, 06:43:08 PM »
 :-[  Very Unfortunately, the most recent long-range models show a westward movement of the North Atlantic high pressure system (Bermuda High) which determines if tropical hurricanes continue their westward path or turn north and east (fish storm). 

This westward movement of the high pressure steering system has locked in a U.S. landfall for Irma.

While the long range models may change significantly and there is a (slight) possibility that large changes may happen going forward, the amount of change that has to happen between now and next Tuesday to allow a miss of the U.S. is so great that it is very unlikely to happen now.

This storm will be a monster in dimension and will likely be a Cat 5 hurricane between now and landfall.  Current models show impact between Florida and Virginia with significant windspeeds (> 100 mph) as far inland as Pittsburgh. 

The water vapor column associated with this storm (and projected central low pressure) are extreme and hourly rainfall totals will likely be unprecedented, though this storm will be a fast moving one, unlike Harvey.,27.78,521/loc=-47.198,41.746

Consequences / Re: Hurricane season 2017
« on: September 01, 2017, 07:26:06 PM »
Very long Range GFS shows Irma as a major hurricane landfall in New England.

Caveat: extremely low reliability at such a long range forecast, could be very different in a few days.

Consequences / Re: Hurricane season 2017
« on: September 01, 2017, 05:10:41 PM »
Again it's just one operational run and one solution of many to come over the next 10 days from multiple models, but the 0z GFS would strike a crippling blow on the US.  It takes a cat 4 with circa 140 mph winds and a giant surge up the Chesapeake Bay.  The Navy base in Norfolk would be wrecked (although the fleet would be sent to sea), and there would be significant damage and disruption in DC, Baltimore, Philly and NY, and points inland with a likely large wind field and battering waves and surge along the coast.  Thankfully this solution is unlikely to verify.

If Harvey doesn't become the straw that breaks the camels back, I would put my money on that one. Holy cow. As you say, its unlikely. But wherever this thing ends up theres going to be trouble.

much too early to say, I am hoping that a large low pressure moving currently through the north east U.S. will shift the dominant high pressure over the Atlantic further east and draw Irma up north prior to hitting Cuba.  That would be the best case scenario and is the reason for the current deviation between GFS and EURO models (EURO holding Irma further south).

Consequences / Re: Conservative Scientists & its Consequences
« on: August 31, 2017, 09:41:02 PM »
I personally think "2 billion" is an absurdly high estimate, but it's OK to disagree.

In this regards, the first attached image should a SkS plot of GMSTA for RCP 8.5 with an ECS of 4.5C; which indicates that GMSTA will reach 2.7C circa 2035 to 2040 assuming these conditions.

If we suddenly stopped all emissions of anthropogenic SO2 we would reach +2.0C within 10 years.

I think you meant to say +1.5C.

+2.0C is still several decades off, if we do not act.

to clarify, along with the +IPO, the total reduction of SO2 emissions will cause an additional +0.5C warming globally.

Arctic sea ice / Re: The 2017 melting season
« on: August 31, 2017, 06:47:20 AM »
Between the cyclone train that is being generated from EPAC toward the pole and the amount of upwelling that was done by Harvey (and more storms this season at this rate), I'm starting to wonder if the levee on our convection budget just breached. Maybe this is the wording we should be using to explain to people how climate change and a runway greenhouse effect work?

Upwelling from Harvey:
Cyclone train from equator toward pole:


the thread you are looking for to post this is here:,2148.msg127394/topicseen.html#msg127394

Consequences / Re: Hurricane season 2017
« on: August 31, 2017, 06:23:43 AM »
Don't know how valid this is but apparently early GFS model projections are a Cat 5 Hurricane Irma headed close to or into the Carolinas.

Consequences / Re: Global Surface Air Temperatures
« on: August 31, 2017, 12:32:35 AM »
with regard to the calculation of CO2e and Global Warming Potential

Standard ratios are used to convert the various gases into equivalent amounts of CO2. These ratios are based on the so-called global warming potential (GWP) of each gas, which describes its total warming impact relative to CO2 over a set period – usually a hundred years. Over this time frame, according to the standard data, methane scores 25 (meaning that one tonne of methane will cause the same amount of warming as 25 tonnes of CO2), nitrous oxide comes in at 298 and some of the super-potent F-gases score more than 10,000.

The only wrinkle with all this is that 100 years is a fairly arbitrary time frame, and the ratios change significantly if a shorter or longer period is chosen. That's because some gases last much longer in the atmosphere than others. For instance, a tonne of CO2 emissions may warm the planet gently but over many centuries. A tonne of methane emissions, by contrast, creates a strong burst of warming over a much shorter period.

Relatively speaking, therefore, the impact of methane – and the strategic importance of tackling its sources, such as agriculture and landfill sites – depends on whether you're more interested in the next few decades or the next few centuries. Over a period of 20 years, methane's GWP rises to 72; over a period of 500 years, it falls to just 7.6.

Consequences / Re: Hurricane season 2017
« on: August 30, 2017, 07:22:59 PM »

Why Harvey Is Stuck Near Texas
Hurricanes gain strength from warmer oceans, but climate change might be causing another problem higher in the sky.

In March, Mann and several colleagues published a study in the journal Scientific Reports that demonstrates a relationship between extreme events, such as the 2011 Texas drought and 2010 Pakistan flooding, and a rare stationary phase that upper atmospheric currents sometimes go through in the mid-latitudes.

Stefan Rahmstorf, a co-author of that paper and head of Earth Systems Analysis at the Potsdam Institute for Climate Impact Research, explained that there may really be several things going on. In general, the jet stream, the high-flying river of air that flows west-to-east, has slowed and gone all wavy in recent summers, with pronounced north-south meanders. That’s one thing that may have helped hold Harvey in place. Researchers have sparred since 2012 over whether Arctic warming, which is occurring at twice the global average, is driving this atmospheric wobble, consequently creating more opportunities for persistent weather farther south.

In a number of extreme cases analyzed by their paper—California drought, Russia’s 2010 heatwave and Pakistan’s related flood—the meandering north-south river of the jet-stream stabilizes for periods of time in some places, creating an insurmountable wavelike band. The researchers looked for some kind of misbehavior in atmospheric circulation after realizing that heat-related effects alone couldn’t explain the extreme nature of some disasters.

James Hansen also discusses this on Democracy Now! today

The Milankovich Cycle's solar input maximized about 7000 years ago

Max 60'N insolation was achieved around 12,000 years ago, it went down after that.

The Earth only needs about 50 to 100 years to fully reverse man-made emissions, because if you actually paid attention to the annual down cycle of the keeling curve, the plant life absorbs around 12ppm per year worth of CO2, but humans currently produce around 14 to 15ppm per year, making a 2ppm or 3ppm excess.

You greatly deceive yourself, kid. Just look at the raw data.

I promise you the next Glacial maximum kills 90% to 95% of all humans on the planet when it happens.

I thought Ghoti was wrong to call you as a denialist troll.

However, you are not doing yourself any good with an attitude of I know it all.

Just because I think Ghoti was wrong does not mean I call him a liar, I think that was an honest mistake.

Just because the biosphere is absorbing 12ppm doesn't mean it will continue to do so until back to preindustrial levels. Baring major new experimentation with carbon cycle, about 25% will remain in the atmosphere declining at only a very slow rate due to rock weathering is the current scientific opinion. That could be wrong but given your know-it-all attitude I would definitely prefer to believe the scientific opinion than what you tell me.

Not nice to wrongly be called a denialist troll, but your response isn't good either. How about a bit more humility?

the biosphere also EMITS about 10 ppm per year in the Northern Hemisphere Fall season.  So the very pretext of the statement about 12 ppm captured per year is not a long-term benefit but rather a seasonal cycle of leaf growth and death in the northern hemisphere (as well as temperature cycles).

Consequences / Re: IPCC possible scenario: 9 C over next century or so
« on: August 30, 2017, 06:10:35 PM »
From the link you posted:

The global warming potential (GWP) represents how much a given mass of a chemical contributes to global warming over a given time period compared to the same mass of carbon dioxide. Carbon dioxide's GWP is defined as 1.0.

Like I said, my heat pump contains 0.7 kg of R-134a refrigerant, times 1300 GWP = 910 kg of CO2.

Okay, I'm less worried now. Thanks for the info, icefest!  :) 8)

This is still off-topic, but just wanted to report that our heat pump was becoming increasingly inefficient. Turns out there isn't enough refrigerant (R134a) in the system, meaning some of it has leaked. There's a plumber pumping out the rest, as I write this, so he can put new refrigerant in.

He put the hose out the window and he was smiling at me while opening the valve. All I could think about was how we added one tonne of CO2e to the atmosphere (6 months of driving with our current CNG-powered car).  :( :'(

Here's to hoping the leak isn't permanent...

sorry for off topic but wanted to follow up.

Typically a charge should last (at least) 7 years.  This refrigerant doesn't have to be vented to atmosphere but can be captured and recycled.  Proper maintenance and operations, especially if R-134 is recycled makes your system much better for the environment.

Consequences / Re: Global Surface Air Temperatures
« on: August 30, 2017, 03:17:47 AM »

Those are warming potentials not forcing,  a much more important value IMO

but by looking only at the 100 year projections we are falsely asserting CH4 power generation is a 'bridge fuel'. 

Have you considered the RF impact of Etminan on the 20 year projection of GWP, knowing that CH4 atmospheric residency is only about 12 years?

I believe that the carbon cycle feedbacks that Shindell et al (2009) cite may take more than 12 years to be fully realized; so until I know better I am referring to GWP100 when calculating CO2e.

I recommend that you do a 20 year calculation nonetheless to see the difference in warming potentials from their respective components.  If you include the Etminan adjustments of shortwave forcing of CH4 it goes up considerably, leading to an even higher fraction of the total warming potential (I estimate it to be an increase of 35% above the Shindell Schmidt value of 105.

Consequences / Re: Global Surface Air Temperatures
« on: August 29, 2017, 08:02:15 PM »

Those are warming potentials not forcing,  a much more important value IMO

but by looking only at the 100 year projections we are falsely asserting CH4 power generation is a 'bridge fuel'. 

Have you considered the RF impact of Etminan on the 20 year projection of GWP, knowing that CH4 atmospheric residency is only about 12 years?

Consequences / Re: Global Surface Air Temperatures
« on: August 29, 2017, 06:52:03 PM »
ASLR Says (with references)

if the radiative forcing for methane is higher, then if modeler's underestimated the historical/paleo negative forcing from aerosol then climate sensitivity may be higher than AR5 assumes.  This point is well illustrated by Shrivastava et al (2017) which states:

Ned says, (without references)

So it means that something else has to give way:

* There is another forcing that is also in error but in the opposite direction
* ECS is lower than previously expected
* TCR is lower than previously expected and the timescale for ECS will be longer than expected


you are out of your element here and I suggest you do some more listening and less talking if you want to understand climate sensitivity, how global energy balances are measured and what their implications are on current methodologies when a change like Etminan (2016) comes along.

Otherwise you start to appear less than ignorant and more like intentionally deceiving self (and others).

The fact is that if the total GHG forcing is revised higher then the Aerosol forcing component is underestimated, suppressing previous warming.  Previous warming is used to determine TCR and there is no Aerosol component in ECS.  This means that an underestimate of the (negative) forcing of aerosols in the historic and paleo models produces a significant revision UPWARDS of ECS (and TCR).

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 09:55:31 PM »

If you had any kind of reading comprehension you would know that my adjustments were for CH4 only.  If you have a different Ch4 adjustment then yours is off. 

In addition, your projections going forward on likely emissions scenarios contain the same bias inherent in the dataset that you used.  These do not include carbon cycle feedbacks, nor do they contain the potential hazards of CH4 emissions from expansion of fracking and natural gas consumption.

Finally, forcing on a long-term potential must include oxidation products and water vapor feedbacks which, again, your calculation neglects to include.  While the N2O adjustment is negative, a larger than projected increase in methane in future years will easily overcome this.  As will the feedbacks that you neglect to include in your long-term graph, though, of course this is inherent in the RCPs and not your fault.

Congratulations on being able to successfully reproduce someone else's work.  When you come up with something new and valid, I am sure I will see it.  For example, your expression of the combined CH4 N2O and CO2 combination forcing going down in future potential emissions scenarios is completely misguided since you don't include the long-term increase in forcing that the entire adjustment is really all about.

To neglect an equivalent increase in absorbed energy from current methane abundances found in Etminan that is equivalent to 118,000 hiroshima bombs per day being absorbed in the biosphere, ABOVE PREVIOUS PROJECTIONS, is short-sighted at best and this short-sightedness makes it quite obvious why you think 1 billion human deaths from climate catastrophe (and related conflict-induced and migration-induced) mortality is an overestimate.

You are a luke-warmer with a spreadsheet, congrats.

I will remind you that the values in Etminan are clearly stated in the abstract of the paper.

RF is about 25% higher (increasing from 0.48Wm−2 to 0.61Wm−2

Since this is the increase value for CH4 forcing on my graph, they are indeed correct.  It is very telling that you think the values Entminan put in his abstract are wrong (according to YOUR calculations of his methodology).   

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 08:49:37 PM »
Sorry, I meant the Last value (2005) which is the value that is quoted in the Entminan paper abstract.

I meant to post this one.

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 08:42:48 PM »
Yesterday, I wrote:

: Ned W
I did the calculations in a hurry, and need to check them over.  But it seems to be possible that over the next couple of decades, the new methods for calculating radiative forcing could well lead to a result that is actually lower than the old methods. 

I re-checked my work, found a minor error that didn't significantly alter the results. 

And here's RCP 8.5, again looking at the forcings in 2035 and 2100 relative to now:

CO2, 2035:  -0.340%
CH4, 2035:  +22.108%
N2O, 2035:  -2.760%
Total, 2035:  +2.653%

CO2, 2100:  +4.550%
CH4, 2100:  +18.335%
N2O, 2100:  -7.702%
Total, 2100:  +5.304%

So in RCP 8.5, Etimnan increases the future forcing (relative to now) at 2035 by 2.7%, and at 2100 by 5.3%


Quick note:

The RCP 8.5 value difference in 2016 between total GHG forcing and CO2 CH4 & N2O forcing is +.355 W/m^2 due to the contribution of trace gasses.

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 08:21:35 PM »
I think you should check your calculations.  The first value in the graph is the 2005 value that is specifically mentioned in the Etminan paper and the adjustment made there is the exact value that the paper calls for. 

So it is not low.

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 08:17:39 PM »
See Graph of the Actual Forcing Series with Etminan Revision, The same historic forcing values were used for AR4 and AR5 (as far as I remember).

Just curious, Jai -- where did you find that graph?

I'm asking because the "Etminan" lines don't actually seem to be based on the equations given in Etminan (2016).  They appear to be slightly too high. 

I used your graph as background, and plotted my calculated values for RF relative to 1765 on top of it (as dots).  Note that the non-Etminan versions line up fine, but the Etminan ones don't match up.  That seems odd.

Methodological note:
I used as input the concentrations from here.  I have not tried to calculate "total anthropogenic forcing" since I'm only looking at the three forcings included in Etminan 2016; so for the total I used PIK's value for TAF, subtracted the non-Etminan versions of the CO2/CH4/N2O forcings, and added back the Etminan versions. 

I took the historic 20th century data at PIK Potsdam for 2005 and adjusted the CH4 component according to Etminan.  I then added this adjustment to the Anthropogenic total.  I then applied this adjustment as a function of total CH4 abundance to the RCP 8.5 concentration values and again added to the difference to the anthropogenic forcing total values.

Methane is currently 1834 ppbv (actually slightly higher this value is 2016:

RCP 8.5 abundance for 2016 is 1853 ppbv so the values I used for the graph are slightly higher than current totals (several year's worth of growth at current rates).

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 06:37:15 AM »
You can lead a horse to water but you can't make him drink.  Well, I led Jai to the edge of the water, anyway.

Seriously, Jai.  Go back, read my previous post, and try doing the calculations for yourself.  Don't tell me about hiroshima bombs or RCP whatever.  Just calculate dF for CO2 from 1750-2017, and then from 2000-2017.  Then, when you've done the math, you can try to put it into words.

That's the beginning.  There's more later.


You are attempting (poorly) to reproduce work that has already been done by people much more talented (and qualified) than you are.

Do yourself a favor and download the spreadsheets that include EVERY greenhouse gas that is being released through human activity.

When you understand how top-of-atmosphere radiation balances are determined, and their components, then you will understand why the revision upward of CH4 RF is so troubling.  It means that the NEGATIVE forcing values in TOA are stronger than has been previously accounted for and indicates much greater long-term warming potential AT CURRENT GHG abundances, once those negative forcing values are removed through fossil fuel consumption declines. 

Permafrost / Re: Modelling permafrost carbon feedback
« on: August 28, 2017, 06:30:01 AM »

Estimates vary on how much carbon is currently released from thawing permafrost worldwide, but by one calculation emissions over the rest of the century could average about 1.5 billion tons a year, or about the same as current annual emissions from fossil-fuel burning in the United States.

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 02:34:32 AM »
Instead of your attempts to calculate the total anthropogenic forcing, I recommend you use the free data that is provided by PIK Potsdam and used by the IPCC.  The value of total CH4 forcing quoted in the Etminan (2016) of 0.48036474 W/m^s can be found there.  That is the value he used and the value that you can then easily adjust to see what the effect is on the Total Anthropogenic forcing value (which is slightly more than the GHG forcing value even though Total Aerosols are extracted from the total).

you can access the data here:

I fully understand what you are trying to say and I agree, under the RCP 8.5 projections through 2035 the series with CH4 adjustments that fit the Etminan (2016) analysis are only increased by 0.05 W/m^2 over the increase in the non-adjusted column. 

However, the TOTAL ADDITIONAL forcing over the non-adjusted column at 2035 is 0.177 W/m^2  or 118,000 Hiroshima bombs per day of extra absorbed radiation.

Consequences / Re: Hurricane season 2017
« on: August 28, 2017, 12:49:42 AM »
Coast Guard flyover reveals stunning scope of Harvey flooding. Everything is underwater.
Brief video at the link.

Those levels are going to go up an additional 6-10 feet.

Consequences / Re: Global Surface Air Temperatures
« on: August 28, 2017, 12:42:03 AM »
future temperature change is a function of total forcing, not additional forcing between now and some future date.  Measured in top of atmosphere radiation imbalance (TOA).  What this revision means is that the TOTAL forcing is higher than previously calculated.  Hansen and Sato (2012) determined a median value of TOA at +0.6 W/m^2. 

Calculations of Global Warming Potential are measured on 20, 100 and 500 year timelines and comparative values are assessed over these time frames of contributions to future warming.  by raising the total forcing at TOA by 0.13 you are effectively adding an additional ~100,000 Hiroshima bombs per day to the total energy accumulation of planet earth.

In addition, Ricke & Caldiera (2014) showed that full warming impact from emissions does not reach full forcing potential (with water vapor feedbacks) for ~8 years.  This means that there is a whole hell of a lot of warming still locked in at current forcing levels.

CH4, measured on a 100-year timeline is approximately 23% of the total forcing profile of GHGs if calculated on a 20-year timeline with Etminan (2016) upward revision, this value goes up to closer to 60% of total warming contribution.

Consequences / Re: Global Surface Air Temperatures
« on: August 27, 2017, 11:01:14 PM »
See Graph of the Actual Forcing Series with Etminan Revision, The same historic forcing values were used for AR4 and AR5 (as far as I remember).
This is the same issue as your previous post, so see my previous answer.

Notice how each pair of lines in your graph is so closely parallel?  There is a gap between the old and new methods, but that gap is not growing much in recent years.  That means the difference between old and new methods arose earlier in the time series. 

So the radiative forcing in 2017 relative to 1750 is a bit higher under the new method.  And the radiative forcing in 2035 relative to 1750 will still be a bit higher under the new method.  But the radiative forcing in 2035 relative to 2017 will be only trivially different between the old vs new methods.


You are completely misunderstanding what the upward revision to CH4 forcing means.  It is an upward revision to the previous calculation of forcing from that source.  That means that, no matter what the baseline, the CH4 forcing values are raised by that much (about 25%)  Redo your calculations and forget about the increase in forcing since a certain time, by not adjusting the baseline value UPWARDS you are underestimating the impact of this revision.

In other words, the 2017 value must be revised upwards (compared to the AR5 value) by at least +0.16 W/m^2

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