Climate change news

Pachauri resigned as head of IPCC. Seems unusual that this is not being widely covered in news media.

Sea level rise along parts of the NE US coast were rising very quickly in 2009-2010. Apparently, changes in the AMOC (the Gulf stream is a better-known term that means roughly the same thing) have changed the shape of the N Atlantic ocean surface. It is not really ‘flat’ at the appropriate scale. This matters, I think, because it concerns a coastal area very significant in economic terms. It is not global sea-level rise nor post-glacial isostatic rebound. It is something that those guys may need to deal with. Spend money to defend against coastline degradation. Whence might that money come? I do not know.

Greenland had less ice coverage during the Holocene Thermal Maximum (HTM). I have not read this paper in Geology (journal), but the abstract is pretty clear. HTM was warmer than (or at least as warm as) the present, at least in the Northern Hemisphere and at least during summers. The ‘at leasts’ are why the paleoproxy global T reconstructions don’t put that time higher than the present. But it was warmer in Greenland; that seems pretty clear. Lower ice cover then is not a particularly cheerful thought. It suggests that ice cover there is not resistant to T increases over millennial scales.

A request is often made for a direct demonstration that CO2 at currently increasing concentrations actually warms the troposphere. This by people who somehow doubt that CO2 absorbs infrared energy, but whatever. That direct demonstration was published in Nature (journal) this week, 25 February, online version (so it will appear in a later print issue). It is almost a 6 MB download, so if you go to a library to get your copy, be prepared. In fact, if memory serves, some well-known doubters have said that the only thing they are waiting for is such a demonstration. So be prepared for some recantations as well . Title “Observational determination of surface radiative forcing by CO2 from 2000 to 2010”. DOI: 10.1038/nature14240

 

Whether Monckton et al have proven that conventional climate models run hot, there is another new study that merits your attention:

Steven J. Smith*, James Edmonds, Corinne A. Hartin, Anupriya Mundra and Katherine Calvin
Near-term acceleration in the rate of temperature change
Nature Climate Change DOI: 10.1038/NCLIMATE2552

After digging in, you will see that they say several things beyond what I present here. For example, Figure 1 shows 70-year periodicities over a millennium that look a lot like ocean dynamics to me.

This was a DOE-funded study (money that mojo didn’t want spent; I hope he recants!) using ‘main stream’ climate models. Under presumptions of climate religion/greatest hoax ever/journal censorship, it would never have been published (well, outside of ‘Energy and Environment’). But here it is. One piece of explanation, RCP8.5 is a scenario where atmospheric CO2 will increase pretty fast, and RCP4.5 is a scenario where atmospheric CO2 will increase pretty slowly and level off soon. Learn more about them from IPCC – their scenarios.

I attach their Figure 4 here, with red circles added by me. It shows that, over a wide range of future CO2 concentrations, conventional climate models do indeed look like they run hot. This is not to say that global air T could not get up above 0.2 oC per decade (the models’ central case), but they are not there now. T is increasing, but not that fast. In addition, whether the 21st century averages 0.2 oC per decade or possibly something less, we have 8.5 decades to go, and you can do the math.



This one study isn’t the whole story, but it has had more effect on me than anything from skeptics. I hope that it gets examined very closely, by all concerned parties. And ‘examined’ means to ask if this study has used all available information and tools in the most appropriate way? How could it be improved? Climate skeptics did not do this work; I reckon they don’t have much to brag about.

I suppose that it could still be wrong; that it might underestimate the ability for some heat already trapped in well-mixed shallow oceans to return to the atmosphere. But to know about that, we’d need a global circulation model that actually ‘does oceans right’. Dangit.

If it is generally correct, we are talking about 2 oC or less during this century, robust across future CO2 trajectories (readers will kindly note that I have never said such here before). If grounded ice can hold, sea level rise would be less than a meter in this century (note: the paper is not about that interesting question, and ice does whatever it wants to). Sea-level rise is not globally uniform, in some places even a little will damage the human enterprise in terms of habitation, agriculture, and shipping – it seems entirely appropriate to identify such places and focus adaptation efforts (money) there. Ocean pH will continue to decline (with atmospheric CO2 increases; it cannot do otherwise), and biological responses to that are a whole ‘nother thing. As it is getting warmer, extreme events will increase in some areas. Looking first to where they have happened in the past makes the most sense and I have always been with Pielke about that.

We need more food, potable water, and energy to improve the human enterprise this century. More protection against, and responses to, adverse effects of climate change (one would entirely miss the point of Smith et al. 2015 by supposing that climate is not changing). We need to find where our boat is leaking, and plug those holes.

But maybe, hopefully, ideally, we have some time. Maybe we have a chance to look at medical externalities of burning fossil C that have previously been ignored. Where can the most money be made (universal goal J ) with renewable energy? Where is burning a better bet? With oil now so cheap, reducing that industry’s tax subsidies could free up a lot of cash to focus on what governments are supposed to do – improve the human condition.

I am very pleased to bring this publication to your attention, and to hear your thoughts about it, and about the larger issues.

 

I want to say that I did not summarize the paper. I selected one point and ran with it in my own direction. Y'all are still assigned to read.

Also I want to remind folks that besides your friendly local librarian, published papers are generally available upon email request to the corresponding author. In this case,

Dr. Stephen J. Smith, Joint Global Change Research Institute, Pacific Northwest National Laboratory, 5825 University Research Court, Suite 3500, College Park, Maryland 20740, USA. *e-mail: [email protected]

The paywall has windows. If I am never obliged to repeat that here (again), it would be just great.

 

Here is summarized another new publication:

Past warming increased snowfall on Antarctica, affecting global sea level -- ScienceDaily

It suggests that previous warm times (specifically around Antarctica) increased snowfall there. From the perspective of T and sea levels,this would act as a negative feedback.

For those concerned about future climate excursions, negative feedbacks are very handy things.

More about Antarctica has come up recently:


East Antarctica Melting could be Explained by Oceanic Gateways | JSG News

They mentioned the journal (Nature Geoscience) but not the DOI (10.1038/ngeo2388).

The study discusses a large area potentially susceptible to 'warm' sea water getting in and causing faster melting. That would be a positive feedback in contrast to the study I mentioned @51. But y'know, Antarctica is complicated.

I have a general tendency to post 'less bad news' about climate change here. However, if there is concern that climate change is not being debated fully enough, I'd need to broaden the scope of publications mentioned here to include 'more bad news'. That would be a bother, for you and me both

Another new one:

Laidre, KL (in press). Arctic marine mammal population status, sea ice habitat loss, and conservation recommendations for the 21st century. Conservation Biology DOI: 10.1111/cobi.12474

These 11 marine mammals have some type of ice dependency, and (northern) sea ice has been reducing since 1979 (satellite era). Polar bears get most of the attention (Ursus frigidarus, I think, in the Hanna/Barbera naming style).

Overall we may say good news, in that there are fewer red boxes than the other non-gray colors. Not so good in the sense that there are so many gray (unknown status) boxes. Perhaps there is a bit of spare cash available for monitoring?

We might be surprised that Polar bears have so many gray boxes, given the attention paid them. I liked the harp seals being all green. Aren't they the ones whose pups get clubbed?

Southern sea ice is a separate matter (and it has been at high stand recently). If anybody knows ice-dependent species there, speak right up. Especially interested in krill.

Anyway, here's your free figure:


and link to the press release:
First global review on the status, future of Arctic marine mammals | EurekAlert! Science News

Another new one:

Scientists predict gradual, prolonged permafrost greenhouse gas emissions, allowing us more time to adapt -- ScienceDaily

suggesting that permafrost is likely to not cause a runaway positive feedback in the near future.

 

Stevens, B. Rethinking the lower bound on aerosol radiative forcing. In press, J.Clim (2015) doi: An Error Occurred Setting Your User Cookie

That sounds interesting. Besides digging into the original, we could read what another researcher has made of it:

The implications for climate sensitivity of Bjorn Stevens’ new aerosol forcing paper « Climate Audit

And it you wonder why I'd post a climate audit link, you haven't long to wonder:

http://www.mpimet.mpg.de/fileadmin/grafik/presse/News/AerosolForcing-Statement-BjornStevens.pdf

Stevens does not like his research being mis- (or over-) interpreted. So the field goes on, with people actually trying to narrow the uncertainties. Good on them. The only losers, perhaps, are those relying on affinity websites to explain scientific research.

I think (have always thought) you are better off going to the original. I know that usually doesn't happen for busy PC readers. But bear in mind that affinity websites might sometimes get things just a tad wrong.

do not know what that cookie thing means. In fact I copied the link from the Nick Lewis.

the doi is 10.1175/JCLI-D-14-00656.1

 

Dangit, I still think the major climate-model problem is periodical sloshes of oceans, minor being clouds and CCN in the atmosphere, and the neglected third is terrestrial carbon cycling. I LIVE in the third. Stevens lives in the second, there within fighting misinterpretations as above.

I have no idea, none whatsoever, who will improve ocean models within a climate framework. Lacking such there is no need to mis-represent predictions of climate models so far with playful graphs. Such models have simply failed to describe important details of T trends through time. What a shame.

Another shame that some of us here imagine that +CO2 can do other than cause +T. Regardless, we are on a path towards 450 to 550 ppm CO2 by mid century. Helpful or problematical, that is our path. The big money has already spoken. Let us take that as so, and make the best of it.

This may mean spending large on adaptation. It seems goofy to to take that money out of scientific research. Other, much larger expenditures present themselves. It would be 'FHO Politics ' to point at military or similar. Perhaps it would not be, to think about fossil-fuel 'financial incentives'. That industry continues to make a buck, whether oil sells for 100 or 50 per barrel. Someone else might make the case that they still now need unique treatment that made sense when that was a fledgling industry.

We all need (depend upon) a growing human enterprise, but it is not clear that our current path is the best one. Changing paths means moving money to other purposes. Who defines the best path, do you reckon? IPCC, NIPCC, or another that has not yet stepped up?

 

One might take, as null hypotheses, that neither T nor SLR will accelerate at all. That they would chug along at the rates of recent decades. In those cases, T in year 2100 (85 years hence) would be 1.43 degrees C higher, and SL will be 25.5 cm higher. I’d have to resort to my notes to do this hazardous extrapolation for ocean pH. Just put your expected end-of-century CO2 and solve the bicarbonate equilibrium equation.

If those rates accelerate, well, it all depends. We have climate models that have not wowed the audience and they might speak to that. Although there are possible positive feedbacks not yet built into any model. Bob mentions coastal erosion of permafrost. Some Antarctic ice is also coastal and grounded below sea level. That is not a complete list, and the number of possible negative feedbacks certainly exceeds zero.

Climate models are ‘not there yet’, but as we have reasons to think about the future, we have reasons to improve them. That is not news, so it is off-topic

 

I would call that something other than a null hypothesis. But anyway...

About 14 thousand years ago was 'Meltwater pulse 1A'. +30 meters in 1000 years. With some trepidation we might consider that the 'speed limit'. OK, add more trepidation because prior conditions had more ice on land than now.

Thus it is hard for me to imagine 3 m/century, starting from here. 1m/century triples the current rate. Such simple approaches don't provide tight constraints. An 'accurate' climate model would do better.