Tag: Global Science Report

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. 

The Progressive Increase of the Urban Heat Island’s Influence on Temperature Records

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.”

Perhaps no other climatic variable receives more attention in the debate over CO2-induced global warming than temperature. Its forecast change over time in response to rising atmospheric CO2 concentrations is the typical measure by which climate models are compared. It is also the standard by which the climate model projections tend to be judged; right or wrong, the correctness of global warming theory is most often adjudicated by comparing model projections of temperature against real-world measurements. And in such comparisons, it is critical to have a proper baseline of good data; but that is easier acknowledged than accomplished, as multiple problems and potential inaccuracies have been identified in even the best of temperature datasets.

One particular issue in this regard is the urban heat island effect, a phenomenon by which urban structures artificially warm background air temperatures above what they normally would be in a non-urbanized environment. The urban influence on a given station’s temperature record can be quite profound. In large cities, for example, urban-induced heating can be as great as Tokyo’s 10°C, making it all the more difficult to detect and discern a CO2-induced global warming signal in the temperature record, especially since the putative warming of non-urbanized areas of the planet over the past century is believed to be less than 1°C.  Yet, because nearly all long-term temperature records have been obtained from sensors initially located in towns and cities that have experienced significant growth over the past century, it is extremely important that urbanization-induced warming – which can be a full order of magnitude greater than the background trend being sought – be removed from the original temperature records when attempting to accurately assess the true warming (or cooling!) of the natural non-urban environment. A new study by Founda et al. (2015) suggests this may not be so simple or straightforward a task.

Fatal Flaw in the USGCRP Climate and Health Assessment

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.”

 

Yesterday, we posted some excerpts from the Background section of our submitted Comment on the draft report on climate and health from the U.S. Global Change Research Program (USGCRP). In that section, we argued that the USGCRP was overlooking (ignoring?) a vital factor that shapes the influence of climate change on the health and well-being of Americans—that is, that the adaptive process is actually spurred by climate change itself. Without recognition of this fact, projections are often alarmist and pessimistic.

Today, we wanted to highlight what we found to be the fatal flaw in the entire USGCRP report—that the USGCRP fails to describe the net impact of climate change on public health, instead, presenting only a narrow and selective look at what they determine to be negative impacts (and even those examples tend to be miscast).

Here’s what we had to say about this:

A Clear Case of Selective Data Usage from the U.S National Climate Assessment

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.”

In the process of writing our upcoming book, The Lukewarmer’s Manifesto, we wandered into the funhouse of the 2014 National Climate Assessment (NCA).

Recall that the NCA is a product of the federal government’s U.S. Global Change Research Program, whose motto isThirteen Agencies, One Mission: Empower the Nation with Global Change Science.”

In their case, “empower” is synonymous with “indoctrinate.”

Here is a good example:

The section on hurricanes in Chapter 2 (“Our Changing Climate”) caught our eye. The NCA has a sidebar on the history of the hurricane “power dissipation index” (PDI), a well-known cubic function of the wind velocity. The NCAs graphs  begin in 1970 and end in 2009 (a full four years before the NCA was released). They include a trend line through the PDI data beginning in 1980 that’s going up for whatever reason and that is apparently convenient for drawing an association with human-caused global warming. But had the NCA authors consulted a longer record, say, from 1920 to 2013 (the last year data was available for the 2014 NCA) they could have readily ruled out any role of global warming.

 

Figure 1. From page 42 of the hardcopy of the 2014 National Assessment Report form the USGCRP (available here).