Air traffic growth set to outpace CO2 reduction efforts Carbon reduction efforts in the airline industry will be outweighed by growth in air-traffic, even if the most contentious mitigation measures are implemented, according to new research by the University of Southampton.

Ancient shellfish remains rewrite 10,000-year history of El Nino cycles
Piles of ancient shells provide the first reliable long-term record for the powerful driver of year-to-year climate changes. Results show that the El Niños 10,000 years ago were as strong and frequent as they are today.

MIT ocean scientist clarifies findings on small net deep ocean cooling in a warming climate (in letter to editor following news story):

Understanding the ocean

THE article by Graham Lloyd will likely leave a mis-impression with many of your readers concerning the substance of our paper that will appear in the Journal of Physical Oceanography (“Puzzle of deep ocean cooling”, 25/7).

We never assert that global warming and warming of the oceans are not occurring — we do find an ocean warming, particularly in the upper regions.

Contrary to the implications of Lloyd’s article, parts of the deep ocean are warming, parts are cooling, and although the global abyssal average is negative, the value is tiny in a global warming context.

Those parts of the abyss that are warming are most directly linked to the surface (as pointed out by Andy Hogg from the ANU).

Scientifically, we need to better understand what is going on everywhere, and that is an issue oceanographers must address over the next few years — a challenging observational problem that our paper is intended to raise.

Carl Wunsch, Harvard University and Massachusetts, Institute of Technology

Key point in new @yaleclimatecomm paper on US climate activism: “The threat posed by climate change should continue to be a component of climate change messaging, but should be accompanied – and perhaps even preceded – by messages on effective actions individuals can take.”

D. Victor on @atomicrod question: Does wind/solar growth in last 5 yrs exceed loss from nuclear shutdowns? >

I haven’t done the numbers independently, but here’s a rough calculation: 
The short answer:  the rise in non-hydro renewables has been about 3x the lost output from the 6 large nuclear plants that have recently announced shutdowns.   
These reactors have announced shutdowns:  Crystal River (unit 3), Kewaunee (one unit), Oyster Creek (one unit), San Onofre (units 2&3) and Vermont Yankee (one unit).  They add up to 4.2GW of capacity.  Predicting just how much power they would deliver is tricky, but if you assume a capacity factor for nukes of 90% (a number that has varied from 86.4% to 91.8% in the last 7 years) then that’s 33.9 thousand gigawatt hours per year of lost power output.  In the real world the capacity factor for these plants might have been a bit lower, but on the other hand had these units not run into trouble during major overhauls then they might have actually seen higher output—Crystal River, for example, shut due to containment damage during construction that would have uprated the plant by 20%.  So treat my 90% of rated capacity as an illustrative magnitude, not the exact gospel truth of exact power output that will be lost.  Other caveats include that I haven’t carefully checked net and gross outputs of each of these closed plants—I pulled the data from NEI and EIA.   But to put this into context, this lost output from these units is around 4% of US nuclear output in 2012.
From 2007 to 2012 (five years) non-hydro renewables have risen from 105 to 218 thousand gigawatt hours—a net increase in output of 113 thousand gigawatt hours per year.  Nearly all of that rise has been wind (105 thousand gigawatt hours).  People seem particularly excited about solar—witness a column by Paul Krugman presaging the new CAA rules that has a special shout out to solar—but wind is doing essentially all the work right now.  
Solar PV and Solar Thermal together  are 4.3 thousand gigawatt hours in 2012, which is a grand total of 0.11% of US net electricity generation.  Hardly a revolution—yet. 
Wind is 3.5% of US net power generation in 2012, up from just 0.8% in 2007.  It has exploded. Whether that is sustainable remains to be seen. I worry a lot about the sustainability of the subsidy regime and grid operations with such large amounts of variable and intermittent supply, but that’s another topic. 
I use 2012 data above because that’s the latest data set from EIA—where possible, I have relied on EIA data.  See table 3.1.A in particular of the Electricity annual along with table 3.1.B

In @newyorker, @nijhuism points to studies showing story beats data in conveying climate change calamity. But African example problematic. Enormous implicit variability and clashing models mean local narratives of change/hardship are not valid reflection of greenhouse-driven climate change. See here, here and here. Sub-Saharan Africa response to greenhouse forcing still unclear:

(see @dotearth post)

yearsoflivingdangerously:

This comic was produced in partnership by Years of Living Dangerously and Symbolia Magazine. For more amazing real life comics, get Symbolia on your iPad or via PDF. And for more information on the biggest story of our time - check out YEARS.

#DivestHarvard blockades president’s office over fossil fuel investments. I like the divestment discussion because of the way it forces new examinations of terms - what is scope of a board’s “fiduciary responsibility” if your definition of “endowment” goes beyond stocks/bonds/ real estate…? A discussion of this here.

In @davidfolkenflik piece on @voxdotcom @upshotnyt I note limits of data-visualization, etc: ”I’ve had this sobering experience since about, well, almost 10 years. I’ve been writing about the social science of how people accept or reject information. You can have clear data, but people who are dug in on an issue just go out and select the data set that reinforce their predisposition…”

(I also said new efforts to convey the meaning behind numbers are vital, mind you, just not nearly sufficient on their own; didn’t make the cut.)

Good @elikint piece on how government cuts in IPCC summary left authors shell-shocked. (One excised graph above.) David Victor, a lead author from UCSD:
“The whole process is kind of unbelievable,” Victor says. As one of the report’s lead authors, he was in the middle of the negotiations. The outcome raises “fundamental questions about whether the IPCC can really do policy-related assessments in areas where the science is most germane to policy,” he writes in an e-mail. “There has always been a tension between the scientific content and the political approval of IPCC reports. But on the scientific issues that probably matter most to policymakers—such as which kinds of countries cause most emissions, who will bear the greatest burdens in controlling emissions, or how international trade affects emissions and policies—the pendulum has swung strongly toward the governments.”
This Dot Earth post is highly relevant: “Nations’ Handling of New Climate Report Presages Divisions in Treaty Effort.”

Good @elikint piece on how government cuts in IPCC summary left authors shell-shocked. (One excised graph above.) David Victor, a lead author from UCSD:

“The whole process is kind of unbelievable,” Victor says. As one of the report’s lead authors, he was in the middle of the negotiations. The outcome raises “fundamental questions about whether the IPCC can really do policy-related assessments in areas where the science is most germane to policy,” he writes in an e-mail. “There has always been a tension between the scientific content and the political approval of IPCC reports. But on the scientific issues that probably matter most to policymakers—such as which kinds of countries cause most emissions, who will bear the greatest burdens in controlling emissions, or how international trade affects emissions and policies—the pendulum has swung strongly toward the governments.”

This Dot Earth post is highly relevant: “Nations’ Handling of New Climate Report Presages Divisions in Treaty Effort.”