Tag: Global Science Report

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.

The Best Government Action on Climate Change Is No Government Action on Climate Change

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.”

Many eyes will be on President Obama’s State of the Union address tonight watching to see how he follows his inauguration promise to “respond to the threat of climate change.” Rumors are flying that he will use his executive power to bypass Congress and further EPA efforts to regulate greenhouse gas emissions. But his best response would be to get the federal government out of the energy market and allow it to flourish as it may. The inconvenient truth is that the U.S. influence on global climate is rapidly diminishing as greenhouse gas emissions from the rest of the world rapidly expand. As a consequence, whether or not the United States reduces its emissions at all is immaterial to the path of future climate change and its impacts.

Several reports last week have shown that carbon dioxide emissions from the United States declined in 2012 and now stand at a level on par with what they were back in 1994. U.S. carbon dioxide emissions have dropped about 13 percent from their high in 2007.

All the while, global carbon dioxide emissions have been on the rise—primarily fueled by rapid emissions growth in developing countries, namely China (which is responsible for about two-thirds of the global increase during the past decade).

Figure 1. Emissions of carbon dioxide from the U.S., China, and the rest of the world, 1990-2010 (data from U.S. Energy Informat

Since carbon dioxide is well-mixed in the atmosphere, who actually emits it is of little consequence when it comes to its potential to lead to global warming.  This means that the global percentage of a country’s annual carbon dioxide emissions is equivalent to its annual percentage contribution to the increased warming pressure (we use the term “warming pressure” to indicate that things other than the atmospheric concentration of greenhouse gases also act to influence that global average temperature from one year to the next). Since total global carbon dioxide emissions are quickly distancing themselves from U.S. emissions, as time passes, the relative influence of U.S. emissions on the future state of the global climate is rapidly declining.

California Irrigation Supplies Water to Phoenix

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.”

California’s Central Valley is one of the true wonders of the agricultural world.  Prior to settlement, it was grassland in its northerly regions (around Sacramento) and desert at the southern end (Bakersfield).  As a result of irrigation from water stored both in the ground and in the many rivers that drain into it, this 1 percent of the nation’s cropland produces 8 percent of our national agricultural output (by value). That doesn’t count the equally productive but much smaller Salinas Valley, which is likely where your artichokes came from.

John Christy, a fellow-lukewarmer (and a Valley native) who is also state climatologist for Alabama, has published extensively that irrigation has changed the Valley’s climate, resulting in a warming produced not by carbon dioxide but by water vapor, which tends to skew heating into the night.

Everything else being equal, increasing the surface moisture in a hot-as-heck environment (like the Central Valley) will increase atmospheric instability, and, given proper conditions, should result in increased convective (thunderstorm) activity. Add in that prevailing mid-atmospheric winds in this region blow from west to east, and you wind up running the increased water vapor uphill into the Sierras, the Wasatch, and the Rockies. That’s pretty much guaranteed to increase thunderstorm activity.

A newly published study fleshes this out with a computer model, and finds that irrigation in the Central Valley of California not only adds water to the local environment but also alters the regional climate across the Colorado River Basin, increasing summer precipitation by 15 percent and Colorado River flow by nearly 30 percent. Those are big numbers and important ones, given the water needs of some 35 million people from Las Vegas to Phoenix to L.A.

Two Wrongs Don’t Make a Right

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 economic heavyweights assembled for their annual summit held by the World Economic Forum (WEF) in Davos, Switzerland, they were greeted by a call for $700 billion/yr of increased spending out to the year 2030 to “to close the green investment gap worldwide, leading to sustainable economic growth that attains global climate change goals.” They were told that this goal can be reached through an additional $36 billion/yr investment from the world’s governments (on top of the $96 billion/yr currently spent) that will “spur up to US$ 570 billion in private capital needed to avoid devastating climate impacts on economy.”

This call was made by the WEF’s own Green Growth Action Alliance as it released its first Green Investment Report at the outset of the Davos conference.

The Green Growth Action Alliance justified the call for the extra spending this way:

Such investments are urgently needed to avoid the potentially devastating impacts of climate change and extreme weather events as witnessed in many parts of the world in 2012. Scientists agree that extreme weather has become the “new norm” and comes at a huge, and rising, cost to the global economic system. Without further action, the world could see a rise in average global temperatures by 4ºC by the end of the century. According to scientists, this could lead to further devastating impacts, including extreme heat waves, more intense tropical storms, declining global food stocks and a sea-level rise affecting hundreds of millions of people.

Using a poor excuse to call for a bad idea doesn’t seem much like progress.

The science of global warming re extreme events is hardly compelling.  The data noise, generated from both natural processes and from other human influences, largely overwhelms any anthropogenic greenhouse effect signal in most cases.

However, compelling evidence is emerging that the magnitude of the climate sensitivity—that is, how much warming we should expect from a doubling of atmospheric carbon dioxide concentration—has been overestimated. Even if there was good scientific evidence that higher temperatures lead to a more “extreme” climate (there’s just about as much evidence for the opposite), an overestimate of the sensitivity would lead to an overestimate of extremes.

And these overestimates are being used by the Green Growth Action Alliance to oversell the need to do something about climate change.

In fact, there are much more pressing needs.