Tag: Global Science Report

The Science vs. the Pseudoscience of Extreme Weather

Over at Capital Weather Gang, the always-perceptive Jason Samenow details a recent Twitterspat between Dot Earth’s (aka The New York Times’) Andrew Revkin and Penn State’s Michael Mann over attributing extreme weather events to anthropogenic climate change—tornadoes, in particular.

Revkin tweeted to ask whether the folks who were alluding to anthropogenic greenhouse gas emissions being behind the major (and deadly) tornado outbreak during the spring of 2011 were willing to attribute the record lack of tornado occurrences during the past 12 months to the same cause.

Revkin could have very well asked this same question about all kinds of bad weather—blizzards, hurricanes, droughts, floods, record heat, record cold, summer in Washington, winter in Chicago, etc.

Used to be, when the weather was bad, folks would logically cite Mark Twain’s “if you don’t like the weather in New England now, just wait a few minutes.”  Now, someone will show up on TV who is quick to point out that this sort of thing “is consistent with” expectations of global warming.  These same folks tend nap when the weather is hunky-dory, and to go into hibernation when the extreme weather category of their previous pronouncement has a hiatus.

Since the bang-up year of 2011, the number of tornadoes has dropped off the table, with the last 12 months showing the fewest since systematic observations began in the 1950s.

And like tornados, major hurricane strikes have also become scarce, in fact, they are so in remission that someone might soon announce they have been cured.  It has currently been more than 7 years since a Category 3 made landfall in the U.S., the longest time in more than 100 years—and all this when overall hurricane activity in the Atlantic basin has been elevated.  Maybe there is something to research that finds that while anthropogenic climate change may increase the frequency of major hurricanes in the Atlantic, it changes the circulation patterns such that they are more likely to remain offshore (see page 30-32 of our comments on the draft National Assessment Report)

But we digress…

Apparently the folks who rally around the anthropogenic climate change/extreme weather linkage don’t like being awoken when all is calm.

Still Another Low Climate Sensitivity Estimate

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

As promised, we report here on yet another published estimate of the earth’s equilibrium climate sensitivity that is towards the low end of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) range of possibilities.

Recall that the equilibrium climate sensitivity is the amount that the earth’s surface temperature will rise from a doubling of the pre-industrial atmospheric concentration of carbon dioxide. As such, it is probably the most important factor in determining whether or not we need to “do something” to mitigate future climate change. Lower sensitivity means low urgency, and, if low enough, carbon dioxide emissions confer a net benefit.

And despite common claims that the “science is settled” when it comes to global warming, we are still learning more and more about the earth complex climate system—and the more we learn, the less responsive it seems that the earth’s average temperature is to human carbon dioxide emissions.

The latest study to document a low climate sensitivity is authored by independent scientist Nic Lewis and is scheduled for publication in the Journal of Climate. Lewis’ study is a rather mathematically complicated reanalysis of another earlier mathematically complicated analysis that matches the observed global temperature change to the temperature change produced from a simple climate model with a configurable set of parameters whose actual values are largely unknown but can be assigned in the model simulations. By varying the values of these parameters in the models and seeing how well the resulting temperature output matches the observations, you can get some idea as to what the real-world value of these parameters are. And the main parameter of interest is the equilibrium climate sensitivity. Lewis’ study also includes additional model years and additional years of observations, including several years from the current global warming “hiatus” (i.e., the lack of a statistically significant rise in global temperature that extends for about 16 years, starting in early 1997).

We actually did something along a similar vein—in English—and published it back in 2002. We found the same thing that Lewis did: substantially reduced warming. We were handsomely rewarded for our efforts by the climategate mafia, who tried to get 1) the paper withdrawn, 2) the editor fired—not just from the journal, but from Auckland University, and 3) my (Michaels) 1979 PhD “reopened” by University of Wisconsin.

Burning Books, Burning Witches, Burning Corn

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

 

History is littered with ideology gone awry.

The most recent example? Burning corn as a substitute for fossil fuels in an effort to mitigate anthropogenic climate change (which supposedly has a negative impact on the production of crops such as corn).

This is about as logical as publicity-stunt burnings of Harry Potter books because of objections to the contents within, which only results in more people buying and reading the books to find out what got the book-burners so inflamed in the first place.

With Harry Potter it was the fantasy world of witchcraft and wizardry. With corn ethanol it is the fantasy world of agriculturally damaging climate change.

A few years ago, a paper was published in the prominent scientific journal Science by Stanford’s David Lobell and colleagues that reported that human-caused global warming over the past 30 years resulted in a slowdown in global crop production. Modeling the climate response of the world’s four largest commodity crops—corn, rice, wheat, and soybeans—Lobell’s team calculated that as a result of rising temperatures and precipitation changes, global crop production was about 3 percent less than it otherwise would have been.

But consider this: The United States produces about 36 percent of the world’s corn. And about 40 percent of U.S. corn is used to produce ethanol for use as a gasoline substitute in an attempt to lower net carbon dioxide emissions from driving and reduce climate change. Globally, corn makes up 30 percent of total worldwide production of the four crops studied by Lobell’s group.

Multiply all these percentages out, and you get that the United States is burning a bit more than 4 percent of global crop production in an attempt to mitigate a climate-driven loss of 3 percent of the global crop production.

Rare “It’s Not as Bad as We Thought” Finding Published

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.

From the authors of a new paper just-published in the journal Nature Geoscience comes this surprising finding:

Tropical forests are less likely to lose biomass – plants and plant material – in response to greenhouse gas emissions over the twenty-first century than may previously have been thought.

A rare “not as bad as we thought” admission about the impacts of manmade global warming!

Not only that, but based on recent findings that the true climate sensitivity is much lower than climate models emulate—findings not incorporated in new study—the results are probably still even more “not as bad as they thought” than they thought!

Chris Huntingford from the U.K’s Centre for Ecology & Hydrology and colleagues coupled climate model projections to a land surface/vegetation model to see how the tropical forests in the Americas, Africa, and Asia respond to changes in atmospheric conditions. Their vegetation model includes interactions between terrestrial plants and influences such as temperature, precipitation, and the carbon dioxide concentration of the atmosphere (a plant fertilizer).

Unlike other studies which used a very limited selection of climate models and less sophisticated vegetation models, the Huntingford team found that in virtually all future simulations that the biomass of tropical forests increases over the course of the 21st century. This is a significantly different result than many previous which suggested that anthropogenic climate change would lead to, as Huntingford et al. put it, “catastrophic losses of forest cover and biomass.”

Perhaps most interestingly, the major driver for the biomass increase is the projected growth in atmospheric carbon dioxide concentration (thanks to our use of fossil fuels). The model projected changes in precipitation had little impact on the biomass predictions and the projected increase in temperature acted to decrease the biomass (although not as much as additional carbon dioxide acted to increase it).

Which is why the results probably get even better if there is less warming associated with carbon dioxide emissions than current generation climate models predict (new research suggest that climate models together produce about 50% more warming than they should).

The authors are quick to mention that uncertainty abounds, as our level of understanding of forest response to changing environmental conditions is not all that high. But even given these uncertainties, the authors are confident that their results of increasing biomass are robust. Here is how Huntingford described the situation in a press release:

The big surprise in our analysis is that uncertainties in ecological models of the rainforest are significantly larger than uncertainties from differences in climate projections. Despite this we conclude that based on current knowledge of expected climate change and ecological response, there is evidence of forest resilience for the Americas (Amazonia and Central America), Africa and Asia.

Resilience. A refreshingly honest assessment of an ecosystem response to climate change. And one that is probably a much more apt descriptor of natural systems than “delicate,” “sensitive,” or “fragile.”

Now if only the folks in charge of assembling national and international climate impact assessments would realize (or probably more accurately, admit to) this.

We are hard at work trying to focus their attention as we are vigorously reviewing the latest draft “National Assessment” of climate change.  We will leak out particularly juicy snippets in these pages when the time seems right.

Reference:

Huntingford, C. et al., 2013. Simulated resilience of tropical rainforests to CO2-induced climate change, Nature Geoscience, 10.1038/NGEO1741.

Did Global Warming Prevent a Record-Breaking D.C. Snowstorm?

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

We haven’t seen any media stories relating global warming to the Wednesday’s weather in D.C.

We are certain that this would not have been the case had more than 11.5 inches of snow accumulated at Reagan National Airport, as it would have set the District’s all-time daily March snowfall record. Exceeding 8.5 inches would have set the record daily March snowfall observed at DCA (an accumulation well within the forecast range) and would probably have generated some global warming comments (after all, they were already waiting in the wings).

Is it only us, or does it seem that postmortem analyses of weather events only include the “consistent with human-caused global warming” meme when the event caused harm and suffering?

If our pernicious industrial activity impacts “extreme” weather, doesn’t it impact the non-extreme as well?

Despite what the global warming alarmists would like you to believe, there are a lot more of the latter than the former!

So was Wednesday’s non-record-breaking non-extreme non-snowstorm in D.C. “consistent with global warming?”

The simple answer: sure!

The temperature was just a wee bit too high for the snow to stick. And human emissions of greenhouse gases have caused a wee bit of temperature rise. Voila! Consistency.

A Case Study of How the Media Influences Popular Perception of Science

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.” 

Today’s  global media are ablaze with coverage of newly reported scientific findings purporting to show that anthropogenic global warming is leading to more extreme weather events such as heat waves, forest fires, and floods.

The findings are being made available in the early releases section of the Proceedings of the National Academy of Sciences (PNAS) and represent the work of a group of researchers from the Potsdam Institute for Climate Impact Research (PIK)—an institute which can be routinely counted on to produce rather alarming climate change studies. The new analysis, led by Vladimir Petoukhov, is no exception. 

The researchers examined the trends in the daily patterns of air flow in the lower atmosphere and found that some patterns had become more persistent with time—a characteristic that leads to a slowdown in the forward motion of weather systems. Or as the researchers put it in their press release, “What we found is that during several recent extreme weather events these planetary waves almost freeze in their tracks for weeks.” To make sure you understand the implications, they added “Since many ecosystems and cities are not adapted to this, prolonged hot periods can result in a high death toll, forest fires, and dramatic harvest losses.”

While climate alarm plays well in the media, what doesn’t play so well is climate-as-normal.

Case and point: there are zero media stories about a similarly timed study purporting to show that any anthropogenic global warming influence on extreme weather events is too small to be reliably detected.

This study, available in the early-release section of the journal Geophysical Research Letters, was performed by the research team of James Screen and Ian Simmonds of the University of Melbourne. Screen and Simmons examined the trends in the daily patterns of air flow in the lower atmosphere and found little significant change. They note that “the changes in meridional amplitude over recent decades are relatively small compared to the year-to-year variability” and “that possible connections between [anthropogenic global warming] and planetary waves, and the implications of these, are sensitive to how waves are conceptualized.” They cautiously conclude that “[t]he contrasting meridional and zonal amplitude trends have different and complex possible implications for midlatitude weather, and we encourage further work to better understand these.”

[Layman’s translation: There are few significant changes in north-to-south extent of jet stream troughs or their forward speed. The data are so noisy that results are highly dependent upon what analytical method is chosen. The contrasting north-south and east-west changes in jet stream troughs have multiple influences that we haven’t sorted out yet, but it would be foolish to tie them to global warming at this time.]

U.S. Greenhouse Gas Follies

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

Carbon dioxide regulations promulgated by the EPA are based upon the assumption that they will actually do something about climate change in the U.S., and that the rest of the world, which had been needling the U.S. for decades of inaction, will now follow our virtuous lead. 

Neither is going to happen.

This Report is based upon just-released data from the U.S. Energy Information Administration showing that the amount of carbon dioxide emitted from the U.S in the last year was the about the same as was emitted in 1994—nearly two decades years ago.  During that time, emissions grew steadily for 14 years, peaking in 2007, and then fell dramatically (Figure 1). The emissions in 2012 were 12% less than those of 2007.

Figure 1. U.S. annual carbon dioxide emissions, 1994-2012 (data source: U.S. Energy Information Administration).
Given this non-trivial decline in carbon dioxide emissions, let’s see how the government’s assumptions are holding up.