Tag: Global Science Report

Taming the Greenland Melting Global Warming Hype

Global Science Report is a 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.”

There is a new paper generating some press attention (e.g. Chris Mooney at the Washington Post) that strongly suggests global warming is leading to specific changes in the atmospheric circulation over the Northern Hemisphere that is causing an enhancement of surface melting across Greenland—and of course, that this mechanism will make things even worse than expected into the future.

We are here to strongly suggest this is not the case.

The new paper is by a team of authors led by Marco Tedesco from Columbia University’s Lamont-Doherty Earth Observatory. The main gist of the paper is that Arctic sea ice loss as a result of human-caused global warming is causing the jet stream to slow down and become wigglier—with deeper north-south excursions that hang around longer.  This type of behavior is referred to as atmospheric “blocking.”

If this sounds familiar, it’s the same theoretical argument that is made to try to link wintertime “polar vortex” events (i.e., cold outbreaks) and blizzards to global warming. This argument which has been pretty well debunked, time and time again.

Well, at least it has as it concerns wintertime climate.

The twist of the new Tedesco and colleagues’ paper is that they’ve applied it to the summertime climate over Greenland. They argue that global warming is leading to an increase in blocking events over Greenland in the summer and that is causing warm air to be “locked” in place leading to enhanced surface melting there. Chris Mooney, who likes to promote climate alarm buzzwords, refers to this behavior as “weird.” And he describes the worrysome implications:

The key issue, then, is whether 2015 is a harbinger of a future in which the jet stream keeps sending Greenland atmospheric systems that drive major melt — and in turn, whether the Arctic amplification of climate change is driving this. If so, that could be a factor, not currently included in many climate change simulations, that would worsen the ice sheet’s melt, drive additional sea level rise and perhaps upend ocean currents due to large influxes of fresh water.

As proof that things were weird over Greenland in recent summers, Tedesco’s team offers up this figure in their paper:

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This chart (part of a multipanel figure) shows the time history of the North Atlantic Oscillation (NAO—a pattern of atmospheric variation over the North Atlantic) as red bars and something called the Greenland Blocking Index (GBI) as the black line, for the month of July during the period 1950-2015. The chart is meant to show that in recent years, the NAO has been very low with 2015 being “a new record low of -1.23 (since 1899),” and the GBI has been very high with the authors noting that “[c]oncurrently, the GBI also set a new record for the month of July [2015].” Clearly the evidence is showing that atmospheric blocking increasing over Greenland which fits nicely into the global warming/sea ice loss/wiggly jet stream theory.

So what’s our beef?

A couple of months ago, some of the same authors of the Tedesco paper (notably Ed Hanna) published a paper showing the history of the monthly GBI going back to 1851 (as opposed to 1950 as depicted in the Tedesco paper).

Here’s their GBI plotted for the month of July from 1851 to 2015:

This picture tells a completely different story. Instead of a long-term trend that could be related to anthropogenic global warming, what we see is large annual and multidecadal variability, with the end of the record not looking much different than say a period around 1880 and with the highest GBI occurring in 1918 (with 1919 coming in 2nd place). While this doesn’t conclusively demonstrate that the current rise in GBI is not related to jet stream changes induced by sea ice loss, it most certainly does demonstrate that global-warming induced sea ice loss is not a requirement for blocking events to occur over Greenland and that recent events are not  at all “weird.”  An equally plausible, if not much more plausible, expectation of future behavior is that this GBI highstand is part of multidecadal natural variability and will soon relax back towards normal values.  But such an explanation isn’t Post-worthy.

Another big problem with all the new hype is that history shows the current goings-on in Greenland to be irrelevant, because humans just can’t make it warm enough up there to melt all that much ice. For example, in 2013, Dorthe Dahl-Jensen and her colleagues published a paper in Nature detailing the history of the ice in Northwest Greenland during the beginning of the last interglacial, which included a 6,000 year period in which her ice core data showed averaged a whopping 6⁰C warmer in summer than the 20th century average. Greenland only lost around 30% of its ice with a heat load of (6 X 6000) 36,000 degree-summers. The best humans could ever hope to do with greenhouse gases is—very liberally—about 5 degrees for 500 summers, or (5 X 500) 2,500 degree-summers. In other words, the best we can do is 500/6000 times 30%, or a 2.5% of the ice, resulting in a grand total of seven inches of sea level rise over 500 years. That’s pretty much the death of the Greenland disaster story, despite every lame press release and hyped “news” article on it.

While you won’t find this kind of analysis elsewhere, we’re happy to do it here at Cato. 

References:

Dahl-Jensen, D., et al., 2013.  Eemian interglacial reconstructed from a Greenland folded ice core.  Nature 489, doi: 10.1038/nature11789.

Hanna, E., et al., 2016. Greenland Blocking Index 1851-2015: a regional climate change signal. International Journal of Climatology, doi: 10.1002/joc.4673.

Tedesco, M., et al., 2016. Arctic cut-off high drives the poleward shift of a new Greenland melting record. Nature Communications, DOI: 10.1038/ncomms11723, http://www.nature.com/ncomms/2016/160609/ncomms11723/full/ncomms11723.html

Release the Kraken

Global Science Report is a 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.”

Making headlines today (like the one above) is a new paper by Zoë Doubleday and colleagues documenting an increase the population of cephalopods (octopuses, cuttlefish, and squid) over the past 61 years.  The authors, after assembling a data set of historical catch rates, note that this population increase, rather than being limited to a few localized areas, seems to be occurring globally.

End of analysis.

From then on its speculation.

And the authors speculate that human-caused climate change may be behind the robust cephalopod increase. After all, the authors reason, what else has had a consistent large-scale impact over the past six decades? No analysis relating temperature trends (spatially or temporally) to cephalopod trends, no examination of other patterns of climate change and cephalopod change, just speculation.  And a new global warming meme is born—“Swarms of octopus are taking over the oceans.”

There is an overwhelming tendency to relate global warming to all manner of bad things and a great hesitation to suggest a potential link when the outcome is seemingly beneficial. We refer to this as the global-warming-is-bad-for-good-and-good-for-bad phenomenon. It holds a great majority of the time.

In the case of octopuses, squids, and cuttlefish, the authors are a bit guarded as to their speculation of impact of the increase in cephalopod numbers—will they decimate their prey populations or will they themselves provide more prey to their predators? Apparently we’ll have to wait and see.

No doubt, the outcome will be a complex one as is the case behind the observed population increases. Depletion of fish stocks, a release of competitive pressure, and good old-fashioned natural environmental variability are also suggested as potential factors in the long-term population expansion. But complex situations don’t make for great scare stories. Global-warming-fueled bands of marauding octopuses and giant squid certainly do. 

Reference:

Doubleday, Z. A., et al., 2016. Global proliferation of cephalopods. Current Biology, 26, R387–R407.

Arctic Sea Ice Loss Not Leading to Colder Winters

Global Science Report is a 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.”

Although it’s a favorite headline as people shiver during the coldest parts of the winter, global warming is almost assuredly not behind your suffering (the “warming” part of global warming should have clued you in on this).

But, some folks steadfastly prefer the point of view that all bad weather is caused by climate change.

Consider White House Office of Science and Technology Policy (OSTP) head John Holdren. During the depth of the January 2014 cold outbreak (and the height of the misery) that made “polar vortex” a household name, OSTP released a video featuring Holdren telling us that “the kind of extreme cold being experienced by much of the United States as we speak, is a pattern that we can expect to see with increasing frequency as global warming continues.” 

At the time we said “not so fast,” pointing out that there were as many (if not more) findings in the scientific literature that suggested that either a) no relationship exists between global warming and the weather patterns giving rise to mid-latitude cold outbreaks, or b) the opposite is the case (global warming should lead to fewer and milder cold air outbreaks).

The Competitive Enterprise Institute even went as far as to request a formal correction from the White House. The White House responded by saying that the video represented only Holdren’s “personal opinion” and thus no correction was necessary. CEI filed a FOIA request, and after some hemming and hawing, the White House OSTP finally, after a half-hearted search, produced some documents. Unhappy with this outcome, CEI challenged the effort and just this past Monday, a federal court, questioning whether the OSTP acted in “good faith,” granted CEI’s request for discovery.

In the meantime, the scientific literature on this issue continues to accumulate. When a study finds a link between human-caused global warming and winter misery, it makes headlines somewhere. When it doesn’t, that somewhere is usually reduced to here.

You Say Meethane, I Say Meth-ane, Let’s Agree We Don’t Know Where It’s Coming From

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.”

Atmospheric concentrations of methane (CH4)—a greenhouse gas many times more potent than carbon dioxide (at least over shorter time scales)—have begun rising after a hiatus from 1999-2006 that defied all expectations. No one knows for sure why—why they stood still, or why they started up again.

There is a lot of research underway looking into the causes of the observed methane behavior and at least three new studies have reported results in the scientific literature in the past couple of months.

The findings are somewhat at odds with each other.

In February, a study led by Alex Turner, from Harvard University’s School of Engineering and Applied Sciences, was published that examined methane emissions from the US over the past 10 years or so. The researchers compared observations taken from orbiting satellites to observations made from several sites on the earth’s surface. They reported over the past decade “an increase of more than 30% in US methane emissions.” And this increase was so large as to “suggest that increasing US anthropogenic methane emissions could account for up to 30-60% of [the] global increase.”

However, the methodologies employed by Turner et al. were insufficient for determining the source of the enhanced emissions. While the authors wrote that “[t]he US has seen a 20% increase in oil and gas production and a 9-fold increase in shale gas production from 2002 to 2014” they were quick to point out that “the spatial pattern of the methane increase seen by [satellite] does not clearly point to these sources” and added that “[m]ore work is needed to attribute the observed increase to specific sources.”

Perhaps most interestingly, Turner and colleagues note that “national inventory estimates from the US Environmental Protection Agency (EPA) indicate no significant trend in US anthropogenic methane emissions from 2002 to present”—a stark contrast to their findings, and a potential embarrassing problem for the EPA. But, never fear, the EPA is on it. The EPA is now actively re-examining its methane inventory and seems to be in the process of revising it upwards, perhaps even so much as to change its previous reported decline in methane emissions to an increase. Such a change would have large implications for the US’s ability to keep the pledge made at the U.S. 2015 Climate Conference in Paris.

However, the Turner et al. results have been called into question by a prominently-placed study in Science magazine just a couple of weeks later. The Science study was produced by a large team led by Hinrich Schaefer of New Zealand’s National Institute of Water and Atmospheric Research.

Schaefer and colleagues analyzed the changes in the isotopic ratios of carbon in the methane contained in samples of air within ice cores, archived air samples, and more recent measurement systems. Different sources of methane contain different mixtures of methane isotopes, related to how long ago the methane was formed. Using this information, the authors developed a model for trying to back out the methane sources from the well-mixed atmospheric samples. Although such a procedure is somewhat tunable (i.e., you can get pretty much any answer you want (kind of like climate models!)), the authors are pretty confident in their final results. 

Decline in U.S. Greenhouse Gas Emissions Overestimated by More Than a Third

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.”

First China. Now the U.S.

It was big news last November when it was revealed that China had been under-reporting its coal consumption by nearly 20 percent. The big implication was that China’s greenhouse gas emissions were also much larger than being reported, complicating the (then) upcoming U.N. climate negotiations in Paris.

Now comes evidence that the U.S. has been underreporting its methane emissions—a potent greenhouse gas—by some 50 percent or more.  And what’s worse, is that over the past decade or so, instead of methane emissions having declined by about 10 percent as reported by the EPA, they have in fact grown by more than a whopping 30 percent. Not only would this information also have (had it been available) complicated the U.N. Paris talks, but it would have taken a lot of the shine off the U.S. emissions reduction efforts that President Obama was touting at the conference last December.

The new evidence is presented in a just-published paper in the scientific journal Geophysical Research Letters by a team led by Harvard PhD candidate Alexander Turner. Turner and colleagues examined several measures of methane emissions occurring in the U.S. (including in situ measurements and remote satellite observations) and concluded that EPA estimates were way off. They wrote:

National inventory estimates from the US Environmental Protection Agency (EPA) indicate no significant trend in US anthropogenic methane emissions from 2002 to present. Here we use satellite retrievals and surface observations of atmospheric methane to suggest that US methane emissions have increased by more than 30% over the 2002-2014 period… This large increase in US methane emissions could account for 30-60% of the global growth of atmospheric methane seen in the past decade.

The implications are huge—at least when it comes to our advertised role as a supposed leader in climate change mitigation efforts.

Going to Extremes: Federal Climatologist Slams Alarmist Federal Climate Report

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.”

Second only to incidences of high temperature, supporters of government action to restrict energy choice like to say “extreme” precipitation events–be they in the form of rain, sleet, snow, or hail falling from tropical cyclones, mid-latitude extratropical storms, or summer thunderstorm complexes–are evidence that greenhouse gas emissions from human activities make our climate and daily weather worse.

The federal government encourages and promotes such associations. Take, for example, the opening stanzas of its 2014 National Climate Assessment: Climate Change Impacts in the United States, a document regularly cited by President Obama in support of his climatic perseverations:

This National Climate Assessment concludes that the evidence of human-induced climate change continues to strengthen and that impacts are increasing across the country.

Americans are noticing changes all around them. Summers are longer and hotter, and extended periods of unusual heat last longer than any living American has ever experienced. Winters are generally shorter and warmer. Rain comes in heavier downpours.

President Obama often calls out the extreme rain meme when he is running through his list of climate change evils. His Executive Order “Preparing for the Impacts of Climate Change,” includes:

The impacts of climate change – including…more heavy downpours… – are already affecting communities, natural resources, ecosystems, economies, and public health across the Nation.

So, certainly the science must be settled demonstrating a strong greenhouse-gas altered climate signal in the observed patterns of extreme precipitation trends and variability across the United States in recent decades, right?

Wrong.

Heat-related Death Projections Don’t Square with Observations

Global Science Report is a 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 realize that we are 180° out of sync with the news cycle when we discuss heat-related death in the middle of Northern Hemisphere winter, but we’ve come across a recent paper that can’t wait for the heat and hype of next summer.

The paper, by Arizona State University’s David Hondula and colleagues, is a review of the recent scientific literature on “human health impacts of observed and projected increases in summer temperature.”

This topic is near and dear to our hearts, as we have ourselves contributed many papers to the scientific literature on this matter (see here).  We are especially interested in seeing how the literature has evolved over the past several years and Hondula and colleagues’ paper, which specifically looked at findings published in the 2012-2015 timeframe, fills this interest nicely.

Here’s how they summed up their analysis:

We find that studies based on projected changes in climate indicate substantial increases in heat-related mortality and morbidity in the future, while observational studies based on historical climate and health records show a decrease in negative impacts during recent warming. The discrepancy between the two groups of studies generally involves how well and how quickly humans can adapt to changes in climate via physiological, behavioral, infrastructural, and/or technological adaptation, and how such adaptation is quantified.

Did you get that? When assessing what actually happens to heat-related mortality rates in the face of rising temperatures, researchers find that “negative impacts” decline. But, when researchers attempt to project the impacts of rising temperature in the future on heat-related mortality, they predict “substantial increases.”

In other words, in the real world, people adapt to changing climate conditions (e.g., rising temperatures), but in the modeled world of the future, adaptation can’t keep up. 

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