RE: Solar Roadways Facebook report.
Lots of faith. No evidence.
Judgement will have to wait.
real time daily energy outputs.
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RE: Solar Roadways Facebook report.
Lots of faith. No evidence.
Judgement will have to wait.
jai, thanks for that post-from-the-future.
iirc, a recent study found that the amount of fresh water needed to stop the AMOC is less than previously thought. It used to be one sverdrup, iirc, but I can't recall what the new figure is.
In any case, such an adjustment would make your scenario all the more likely.
I think we should start a radio hour with reports from various possible futures back to our current one! Or maybe videos. Like the old "You Are There" series that generally stared Walter Cronkeit.
We need some creativity in getting our messages out to a broader audience, it would seem.
This is a very difficult question to answer and the best any of us can do is hazard a guess.I fully agree with your analysis/educated guess, dnem.
I'm voting 2020-2030.
I wish you'd play devil's advocate and guess a reasoning for 2040-2050 or 2050-2060. Oh well...
In retrospect, you are right. I was being far too conservative for conservatism's sake. Interesting, you caught me self-censoring my answer. changed from 2040-2050 to 2030-2040.
Sorry, my eye just caught that edit of yours. Please don't censor yourself!
But here is a question for you, since you are (at least, compared to me) an old time poster here on ASIF.
Is there some form of peer-pressure or group-pressure here at ASIF for people to emit conservative guesses when it comes to the demise of Arctic sea ice? And for people to shut up when they question this conservative "bias"?
If so, I would think this is very strange. In any case, I am rather reassured that your poll is showing what it is showing: that approximately half the ASIF users are not conceding to the "conservative" peer pressure.
Grasby, along with a team of scientists from institutes in Canada and Europe, discovered evidence for the ancient methane leak during a recent expedition to remote Ellef Ringnes Island in the Canadian Arctic, which they have described in a paper published this month in the Geological Society of America Bulletin. There, they found a cluster of 139 strange, rocky mounds, which they say were formed by a rapid release of large amounts of methane from the ocean floor.
we conclude that models need external forcing to explain the magnitude, timing, and apparent multidecadal frequency of the observed twentieth century AMO variability.
jai - another factor you've completely ignored is the completely different spatial/geographical distributions; high emissions in the early and mid-20th century would have been from Eurpope and North America. In recent decades those areas have seen reduced emissions while Asia/China have greatly accelerated. Expecting the same forcing patter from completely different geographical distributions would seem a bit over-reaching - to put it charitably.
for example, in the first graph, the 1920 line is actually 1917 (if you apply a grid function to determine the actual date instead of eyeballing it like I did) and the 1935 graph line could reasonably be shifted to 1942 since this was when the emissions actually started to increase again (driving the shift in the AMO graph).
Besides how is it we don't see a change when MT Agung or MT Pinatubo erupted?
(note: never mind, I see that you do not have a science education background)
Please tell us the regression statistics.
Merging the emissions graph and Mann et al's "true AMO" graph yields:
For example, Mann and Emanuel 
show that such a procedure misattributes at least part of the forced cooling of the NH
by anthropogenic aerosols during the 1950s-1970s (especially over parts of the North
Atlantic) to the purported down-swing of an internal “AMO” oscillation. A number of
climate modeling studies support their finding [Santer et al, 2006; Booth et al, 2012;
©2014 American Geophysical Union. All rights reserved.
Evan, 2012; Dunstone et al, 2013], though the precise role that anthropogenic
aerosols have played in recent decades continues to be debated in the literature [Koch
et al, 2011; Carslaw et al, 2013; Stevens, 2013].
Jai, your second paper (Bellomo et al 2016) seems to deal mostly with cloud effects over the tropics:From these experiments we conclude that cloud feedbacks can account for 10% to 31% of the observed SST anomalies associated with the AMO over the tropics.
I'm not sure yet how much that has to do with aerosols and the 30's-40's temperature bump in the Arctic.
The present results, combined with this earlier finding, suggest that the indirect effects of anthropogenic sulfate may have contributed to the Sahelian drying trend. More generally, it is concluded that spatially varying aerosol-related forcing (both direct and indirect) can substantially alter low-latitude circulation and rainfall.
For the sstClimAerosol simulation, the cloud albedo effect contributes significantly to the changes in land surface temperature and precipitation pattern (Fig S6).
The transition from a desert to a maritime climate happened in late December 2015.
Based on what? On some plumes of humidity over the Arctic? You don't know if that is an annual variation, or decadal, or what. You know as much as I do or any around (except maybe the owner of the site, Rob, Dr. Ding and a handful more), which is nothing.
Based on a graph? Lol. Based on clairvoyance, a vision in dreams or what?
But I believe there was a clear step change in November/December 2016 (I don't see anything special happening in December 2015, though)
In summary, our results are supportive of the hypothesis that cloud feedbacks favor the persistence of SST anomalies in the tropics via the WES feedback. By detrending the cloud observations, we roughly removed the influence of greenhouse gases. However, we have not examined the possible role of aerosol-cloud interactions on driving phase shifts of the AMO [Booth et al., 2012], which remains an open question.
I doubt that the 30s-40s temperature bump had much to do with aerosols.
The AMO is a much more likely candidate.
Here we use a state- of-the-art earth system climate model, to show that aerosol emissions and periods of volcanic activity explains 76% of the simulated multidecadal variance in
detrended 1860 to 2005 North Atlantic SST. After 1950 simulated variability is
within observational estimates; from 1910-1940 our estimates capture twice the
warming of previous generation models, but do not explain the entire observed
trend. Other processes, such as ocean circulation, may also have contributed to
early 20th century variability. Mechanistically, we find that inclusion of aerosol cloud
microphysical effects, rarely included within previous multi-models
ensembles, dominates the magnitude (80%) and spatial pattern of the total
surface aerosol forcing in the North Atlantic.
But you seem to be saying that to match the pattern of global temperatures, there needs to be an early 1920s dip in albedo increasing aerosols if I understand correctly?
Jai, Planning on further increases in total emissions to 1000 Gt or more is likely or worse inevitable.
I still think there is uncertainty in whether current anthropogenic emission trends or feedbacks are feeding CO2 atmospheric levels. Probably some of each. Rboyd posted a EIA revision in China's contributions that illustrates our problems with parsing out anthro from feedbacks.
"Energy-content-based coal consumption from 2000 to 2013 is up to 14% higher than previously reported, while coal production is up to 7% higher"
We should assume other countries fudge their emission figures as well and any reports of a flattening of anthro CO2 is premature. If on the other hand feedbacks are in majority the reason we see continued atmospheric CO2 increases the 1000 Gt number may far short of what is necessary to somehow drawdown, whenever we figure out how to do so.
I also agree the ocean will give back what CO2 it has absorbed but the timeframe of that release may be in the thousand year timeframe. Remember also that the ocean has more ability to hold CO2 at cold temperatures so as we heat the oceans they will actually return more CO2 than what it has absorbed .
The amount of the return from the oceans is dependent on the gas partial pressure difference between the ocean and the atmosphere like you stated.
Global precipitation is reduced by around 4.5%, and significant reductions occur over monsoonal land regions: East Asia (6%), South Africa (5%), North America (7%), and South America (6%).
Dr. Ding has just posted a reference to a paper (Armour et al 2011) that posits - based on model simulations - the total reversibility of the observed loss of Arctic sea ice*, if we just remove CO2 from the atmosphere as fast as we have added it (by what means is not specified, but refer to the "geoengineering activities" jai mitchell mentions above).
* >80% loss of September Arctic sea ice volume in < 40 years, according to Axel Schweiger, one of Dr. Ding's co-authors in the latest Ding et al paper on natural variability attribution.
Personally, I think anyone that voted anything other than 2020-2030 in the poll above is a denialist, consciously or not.
jai mitchell, you posted a link to a YouTube video of a Kevin Anderson interview during COP21. At 9 minutes there is his opinion on negative emissions (removal of CO2 from the atmosphere). Needless to say, I agree with Kevin Anderson on all the points he makes during that interview. Basically, relying on future negative emissions (for which the technology does NOT exist), or on a carbon budget (which we have exhausted a long time ago), or on "natural variability" that is supposed to bring a comeback of Arctic sea ice, are all distractions and wishful thinking.
This is the reality of CO2 atmospheric concentration, and there is no denying it:
The most intriguing part of that event is that warming exhibited a pretty large scale feature in the Arctic and the area was warmed by something very fast from 1920s to 1930s. So causes of this fast warming rate has puzzled me for a long time.
I wonder if the global recession beginning in 1929 could be to blame for the spike in Arctic temperatures? Similar to what we are seeing as China winds down its dirtiest pollutants.
jai mitchell +1
I've been meaning to say this for a while, and this is offtopic, but your coal/aerosols/sst argument is a courageous one. You are saying that shutting down Coal plants causes short term global warming. I bet you get a lot of flak for that.
When you first started to state that point, I was suspicious of you because it sounded like a very convenient argument for a climate change denier to take advantage of. But then as you refined the argument and presented more and more evidence I realized that my suspicions of your argument were nothing but my own personal bias. You are probably right and your argument is very important if coal is going to be phased out.
For example phasing out coal plants during warm cycles of the planet will compound the problems of the warming. Closing them during cool earth cycles will reduce the impact of the short term warming at the cost of maintaining the Earth at a higher temperatures for longer.
This might be an important consideration that is impossible to talk about because of the nature of the debate.
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