May 26, 2011

No Long-term Trend in Atlantic Hurricane Numbers

Filed under: Climate Extremes, Hurricanes

Long-debated has been whether or not there is a long-term trend in the number of Atlantic tropical storms and hurricanes.

The answer to this seemingly straightforward question turns out to be complicated because there have been changes in the observing practices over time—including changes in the spatial coverage of observing systems as well as the technologies employed. Therefore, teasing out the real climate signal from the noise induced by the changing nature of the observations has proved challenging and lends itself to a variety of methodologies producing a variety of results.

Of top of this less than perfect solution is the desire (for some at least) to want to try to involve anthropogenic global warming, hoping to find that anthropogenic climate change is leading to more tropical storms and hurricanes. But thus far, the evidence for this is scant, to say the least.

And now, it just got scanter. (We know the word is “scantier” but the one we concocted rhymes with our pugilistic friend in climate hyperbole, Ben Santer).


May 23, 2011

Less Cooling Means Less Warming

Filed under: Aerosols, Climate Forcings

We occasionally highlight articles from the scientific literature showing that the cooling impact of aerosol emissions from human activities has been overestimated. Such findings are important because they mean that warming from greenhouse gases has been similarly overestimated.

Climate models rely on aerosol cooling to keep warming in check—otherwise they predict far more warming to occur than has been observed. So, if aerosols produce less cooling, then this means that the climate models must compensate by producing less warming from greenhouse gases than they do presently. If they don’t, they will fail to replicate the observed temperature history.

In a paper soon to appear in Geophysical Research Letters, an M.I.T. research team led by Jason Cohen finds that by including in climate models aerosol-influencing processes that take place in urban environments, the total global-average negative forcing (i.e., cooling pressure) from aerosols is significantly less than when these urban processes are not considered—as is currently the case with all climate models.


May 11, 2011

Crabs Love Warmer Water!

Filed under: Adaptation, Animals

Who would ever guess that in 2011, one of the most popular television shows in the world is about fishing for crabs in “the vast Bering Sea.” Deadliest Catch premiered on the Discovery Channel on April 12, 2005 and currently airs in over 150 countries. If you don’t know, the show portrays the real life events aboard fishing vessels in the Bering Sea during the fall Alaskan king crab and the winter Opilio crab fishing seasons. With so much interest in the show and so much concern about climate change in the high latitudes of the Northern Hemisphere, it was just a matter of time before we explored the world of crabs and climate change.

Our interest in this subject actually came about given a recent article in the Journal of Experimental Marine Biology and Ecology. The article was produced by three scientists from Oregon; Stoner et al. acknowledge that “This study was conducted as part of the AKCRRAB Program (Alaska King Crab Research, Rehabilitation, and Biology) funded by the NOAA Aquaculture Program and the Alaska Sea Grant College Program.” They note in their introduction that “Red king crab (Paralithodes camtschaticus) (RKC) was the most economically valuable crustacean fishery in Alaska from the late 1960s, until the population collapse in the early 1980s. Both over-harvest and unfavorable environmental conditions probably contributed to low fishery recruitment. Various fishing closures have been imposed in the Gulf of Alaska and Bering Sea for more than two decades, but the stocks have not recovered substantially.”

Regarding any link to climate change, Stoner et al. state “Temperature is a dominant environmental factor that mediates the behavior, physiology, growth, survival, distribution, and recruitment of ectothermic animals living in temperate and high latitudes. Consequently, climate-driven changes in ocean conditions can cause significant fluctuations in the distribution and abundance of marine populations. In the Gulf of Alaska and Bering Sea, oceanographic regimes linked to climate conditions occur on a multi-decadal scale, and these climate cycles have been linked to major temporal shifts in the composition of marine fish and invertebrate communities. Longer-term trends in sea surface warming and loss of sea ice have already been observed in the Gulf of Alaska and Bering Sea, and the potential impacts on economically important species are large.”


May 4, 2011

Climate Coup Book Forum

Filed under: Climate Politics

The Cato Institute is hosting a Book Forum at 4:00pm E.D.T. TODAY!! [the event has come and gone, although an archive of it may be available soon] (Wednesday May 4th, 2011) to introduce and discuss Dr. Patrick Michaels’ latest book, Climate Coup: Global Warming’s Invasion of Our Government and Our Lives.

The forum features Richard Lindzen, Alfred P. Sloan Professor of Meteorology, MIT and Bob Ryan, Fellow and past president of the American Meteorological Society and meteorologist for WJLA / ABC 7 News. It is being moderated by Patrick J. Michaels, Senior Fellow, Cato Institute, and editor of Climate Coup.

The Cato Institute is offering a webcast of the event. Details on how to tune in are available here .

Be sure to check it out!

May 2, 2011

Attempts to Box Us Out

We dedicated our last World Climate Report post to the findings from our just-published (and quite popular) paper in which we attempted a reconstruction of the warm season ice melt extent that has taken place across Greenland each year since 1784. Our goal was to develop a larger context in which to place the direct observations of ice melt across Greenland (available only since 1979) and to better be able to judge the reports of record high ice melt in recent years.

Our general conclusions were:

• several recent years (in particular 2007 and from preliminary observations 2010) likely had a historically high degree of surface ice melt across the Greenland ice sheet,

• on a decadal scale, there were several 10-yr periods during the 1930s through the early 1960s during which the average annual ice melt extent across Greenland was likely greater than the most recent 10 years of available data in our study (2000-2009),

• that the ice melt across Greenland was particularly low at the start of the era of satellite observations (which began in 1979), such that a sizeable portion of increasing ice melt observed by satellite-borne instruments since then could potentially be part of the natural variability about the mean state,

• that, for the next several decades at least, Greenland’s contribution to global sea level rise was likely to be modest.

But not everyone was enamored with our findings.


A 225-year reconstruction of Greenland ice melt

Last week, the most popular article from among those recently published in the American Geophysical Union’s (AGU) Journal of Geophysical Research-Atmospheres was one which presents a 225-yr reconstruction of the extent of ice melt across Greenland. We are happy to say that your obedient servants here at World Climate Report were part of the research team of this oft-downloaded paper.

The full citation (for those who may want to check it out) is:

Frauenfeld, O.W., P.C. Knappenberger, and P.J. Michaels, 2011. A reconstruction of annual Greenland ice melt extent, 1785-2009. Journal of Geophysical Research, 116, D08104, doi: 10.1029/2010JD014918.


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