@ChasingIce screening for @BeaconSloopClub had insights from Radley Horton, Marco @CryoCity Tedesco, director @JeffOrlowski and even a Lord Franklin Redux performance by me and David @TerraNova Rothenberg.
New Nature paper (Tingley, Huybers) finds recent extreme Arctic (and peri-Arctic) warmth unique in last 600 years. Here’s abstract, followed by figure caption:
Recently observed extreme temperatures at high northern latitudes1, 2, 3, 4, 5, 6, 7 are rare by definition, making the longer time span afforded by climate proxies important for assessing how the frequency of such extremes may be changing. Previous reconstructions of past temperature variability have demonstrated that recent warmth is anomalous relative to preceding centuries2, 8,9 or millennia10, but extreme events can be more thoroughly evaluated using a spatially resolved approach that provides an ensemble of possible temperature histories11, 12. Here, using a hierarchical Bayesian analysis13, 14 of instrumental, tree-ring, ice-core and lake-sediment records, we show that the magnitude and frequency of recent warm temperature extremes at high northern latitudes are unprecedented in the past 600 years. The summers of 2005, 2007, 2010 and 2011 were warmer than those of all prior years back to 1400 (probability P > 0.95), in terms of the spatial average. The summer of 2010 was the warmest in the previous 600 years in western Russia (P > 0.99) and probably the warmest in western Greenland and the Canadian Arctic as well (P > 0.90). These and other recent extremes greatly exceed those expected from a stationary climate, but can be understood as resulting from constant space–time variability about an increased mean temperature.
~~~
Caption for excerpted figure: Warm and cold extremes. The fraction of all locations for which years were warmest or coolest, averaged across all ensemble members. Results are binned by decade, except for the last interval, which contains only 2010–2011.
Nice @simonsfdnorg piece on efforts to improve Southern Ocean element in climate models. “Scientists Parse Ocean’s Dynamic Role in Climate Change.” Here’s caption/credit for image:
A schematic of global ocean circulations developed by DIMES principal investigators John Marshall of MIT and Kevin Speer of Florida State University in 2012, based on the current understanding of ocean dynamics. Cooler colors indicate denser water masses. (Illustration: John Marshall and Kevin Speer)
.@realitydrop #climatehawks try flooding blogosphere comment zone. But will it matter? The online climate wars — which seem so momentous to those deeply dug in on various fronts — are taking place on the sharp end of a needle buried in a haystack of other societal concerns. Post is at Dot Earth.
.@cenmag: Jim Hansen’s last paper while at NASA finds big health & CO2 benefits from nuclear power in place of coal:
Using nuclear power in place of fossil-fuel energy sources, such as coal, has prevented some 1.8 million air pollution-related deaths globally and could save millions of more lives in coming decades, concludes a study. The researchers also find that nuclear energy prevents emissions of huge quantities of greenhouse gases. These estimates help make the case that policymakers should continue to rely on and expand nuclear power in place of fossil fuels to mitigate climate change, the authors say (Environ. Sci. Technol., DOI: 10.1021/es3051197).]
Some question why I dinged Easter @realclimate release of Marcott et al FAQ as “irksome.” Here’s my reply to one critic:
As for Easter Sunday, perception (whether your or I like it) is reality. Gavin and Mike would have done better to have waited til Monday at least to avoid the perception.
And it IS, in fact, irksome for those of us responsible for tracking events that constitute news:
irk·some
/ˈərksəm/
Adjective
Irritating; annoying.
Synonyms
tiresome - tedious - wearisome - annoying - bothersome
Nice followup to my 2011 conversation with Josh Willis, “Straight Talk on Rising Seas in a Warming World.”
How much and how fast will sea level rise in the coming decades? What makes sea level rise hard to predict? Who will be affected?
Join NASA experts and guests to discuss how sea level has risen an average of about seven inches around the globe since 1900, and has been accelerating in recent…
Climate models challenged by PNAS paper showing Pacific & Atlantic cycles driving monsoon trends during recent warming (news release):
Bin Wanga, Jian Liu, Hyung-Jin Kim, Peter J. Webster, So-Young Yim, and Baoqiang Xiang
Prediction of monsoon changes in the coming decades is important for infrastructure planning and sustainable economic development. The decadal prediction involves both natural decadal variability and anthropogenic forcing. Hitherto, the causes of the decadal variability of Northern Hemisphere summer monsoon (NHSM) are largely unknown because the monsoons over Asia, West Africa, and North America have been studied primarily on a regional basis, which is unable to identify coherent decadal changes and the overriding controls on planetary scales. Here, we show that, during the recent global warming of about 0.4°C since the late 1970s, a coherent decadal change of precipitation and circulation emerges in the entirety of the NHSM system.
Surprisingly, the NHSM as well as the Hadley and Walker circulations have all shown substantial intensification, with a striking increase of NHSM rainfall by 9.5% per degree of global warming. This is unexpected from recent theoretical prediction and model projections of the 21st century. The intensification is primarily attributed to a mega-El Niño/Southern Oscillation (a leading mode of interannual-to-interdecadal variation of global sea surface temperature) and the Atlantic Multidecadal Oscillation, and further influenced by hemispherical asymmetric global warming.
These factors driving the present changes of the NHSM system are instrumental for understanding and predicting future decadal changes and determining the proportions of climate change that are attributable to anthropogenic effects and long-term internal variability in the complex climate system.
Good @portereduardo piece on US CO2 drop ends with familiar call for CO2 price but no roadmap for achieving it.
