Tag: climate change

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.

On the Bright Side: Three Full Decades of CO2-Induced Vegetative Greening in China

Here we introduce a new feature from the Center for the Study of Science, “On the Bright Side.” OBS will highlight the beneficial impacts of human activities on the state of our world, including improvements to human health and welfare, as well as the natural environment. Our emphasis will typically focus on the oft-neglected positive externalities of carbon dioxide emissions and associated climate change. Far too often, the media, environmental organizations, governmental panels and policymakers concentrate their efforts on the putative negative impacts of potential CO2-induced global warming. We hope to counter that pessimism with a heavy dose of positive reporting on the considerable good humans are doing for themselves and for the planet.

According to Piao et al. (2015), the reliable detection and attribution of changes in vegetation growth are essential prerequisites for “the development of successful strategies for the sustainable management of ecosystems.” And indeed they are, especially in today’s world in which so many scientists and policy makers are concerned with what to do (or not do) about the potential impacts of CO2-induced climate change. However, detecting vegetative change, let alone determining its cause, can be an extraordinarily difficult task to accomplish. Nevertheless, that is exactly what Piao et al. set out to do in their recent study.

More specifically, the team of sixteen Chinese, Australian and American researchers set out to investigate trends in vegetational change across China over the past three decades (1982-2009), quantifying the contributions from different factors including (1) climate change, (2) rising atmospheric CO2 concentrations, (3) nitrogen deposition and (4) afforestation. To do so, they used three different satellite-derived Leaf Area Index (LAI) datasets (GLOBMAP, GLASS, and GIMMIS) to detect spatial and temporal changes in vegetation during the growing season (GS, defined as April to October), and five process-based ecosystem models (CABLE, CLM4, ORCHIDEE, LPJ and VEGAS) to determine the attribution.

Spin Cycle: Is Climate Change Already Taking Lives in New England?

The Spin Cycle is a reoccurring feature based upon just how much the latest weather or climate story, policy pronouncement, or simply poo-bah blather spins the truth. Statements are given a rating between 1-5 spin cycles, with fewer cycles meaning less spin. For a more in-depth description, visit the inaugural edition.

The headline from a CBS News story read “Study: Climate change may be costing lives in the U.S.” The tone is in perfect keeping with the White House wanting the media to focus on the (negative) health impacts from climate change to help drive home the “moral imperative” of administration’s greenhouse gas emissions regulations.

There is one key problem: the findings from the “study” do nothing to shed light on whether “climate change” is taking lives in New England (the region that the study focused on) or anywhere else in the United States. In fact, taking the literature as a whole (including the results of the new study), the more appropriate headline would have been “Studies: Climate change may be saving lives in the U.S.”

The new study in question appears in the journal Nature Climate Change written by a research team headed by Liuhua Shi from the Harvard School of Public Health. Shi and colleagues examined how temperature and temperature variability during the summer and winter seasons impacts the annual mortality of Medicare recipients (i.e., a population aged 65+) residing in New England.

In general, Shi and colleagues found that warmer summers slightly increased mortality while warmer winters slightly lowered it. They also found that more variable temperature (in either winter or summer) led to increases in overall mortality.

Aside from the very real possibility that the statistical significance of these findings was inflated by the mythological design (over inflation of the number of independent data points), the most obvious flaw is that the study didn’t look for any trends in their results. This means, of course, that they aren’t very applicable when it comes to trying to ascertain future behavior (under climate change or not).

Science Revives “The Hiatus”

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.”

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Just five weeks after Science magazine prominently featured a paper proclaiming that the multidecadal slowdown in the rate of the earth’s average temperature rise—aka, the “pause” or “hiatus”—was but a figment of bad data, comes a new paper in Science magazine explaining the physical mechanisms that have led to the slowdown.

Wait, what?

You read it right. What Science laid to rest but a month ago, Science has now resurrected. Science (with a capital “S”), and those dedicated to it, should not be amused.

But such is the nature of the game. Science the magazine is more interested in generating publicity for itself than in best serving Science the field—a point being increasingly raised by prominent scientific figures.

The new paper, whose title even contains the dreaded H-word (“Recent hiatus caused by decadal shift in Indo-Pacific heating”), is authored by Veronica Nieves and colleagues from the Jet Propulsion Lab (JPL). The paper itself is rather technical look at how the hiatus has manifested itself in various compilations of measurements (and models) of the ocean’s temperatures at depth.

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:

Comments on 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.”

On June 8th, the public comment period on the draft report on climate and health from the U.S. Global Change Research Program (USGCRP) closed. Never liking to miss an opportunity to add our two cents’ worth to the conversation, we submitted a set of comments that focused on the weakness of the underlying premise of the report, more so than the specific details (although we did include a sample set of those to show just how pervasive the selective and misuse of science is throughout the report).

Our entire Comments are available here. But, for convenience, here’s the highlight reel. In summary, we found:

What is clear from this report, The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment, and all other similar ones that have come before, is that the USGCRP simply chooses not to accept the science on human health and climate and instead prefers to forward alarming narratives, many based on science fiction rather than actual science. To best serve the public, this report should be withdrawn. By going forward without a major overhaul, its primary service [will] be to misinform and mislead the general public and policymakers alike.

Here we lay out the general problem:

The authors of the USGCRP draft of The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment report have an outstanding imagination for coming up with ways that climate change may negatively impact the health and well-being of Americans, but a profound lack of understanding in the manner in which health and well-being is impacted by climate (including climate change).

Spin Cycle: Whither the Hiatus

The Spin Cycle is a reoccurring feature based upon just how much the latest weather or climate story, policy pronouncement, or simply poo-bah blather spins the truth. Statements are given a rating between 1-5 spin cycles, with less cycles meaning less spin. For a more in-depth description, visit the inaugural edition.

Today’s press buzz is about a new paper appearing in this week’s Science magazine which concludes that the “hiatus” in global warming is but a byproduct of bad data. The paper, “Possible artifacts of data biases in the recent global surface warming hiatus,” was authored by a research team led by Director of the National Oceanic and Atmospheric Administration’s National Climatic Data Center, Dr. Thomas Karl. Aside from missing the larger point—that the relevant question is not whether the earth is warming, but why it’s warming so much slower than the computer model projections—the paper’s conclusions have been well-run through the spin cycle.

The spin was largely conducted by the American Association for the Advancement of Science (AAAS), publisher of Science magazine, through its embargo campaign and the courting of major science writers in the media before the article had been made available to the general public (and other scientists). Given the obvious weaknesses in the new paper (see below and here, for starters), there seems the potential for more trouble at Science—something that Editor-in-Chief Marcia McNutt is up to her eyeballs with already.

One major problem with the new Karl and colleagues paper is that the headline-making finding turns out not even to be statistically significant at the standard scientific level—that is, having a less than 1-in-20 chance of being due to chance (unexplained processes) alone.

Instead, the results are reported as being “statistically significant” if they have less than a 1-in-10 chance of being caused by randomness.

More and more we are seeing lax statistical testing being applied in high profile papers (see here and here for recent examples). This tendency is extremely worrisome, as at the same time, the validity of large portions of the scientific literature is being questioned on the basis of (flawed) methodological design and poor application and interpretation of statistics. An illuminating example of how easily poor statistics can make it into the scientific literature and produce a huge influence on the media was given last week in the backstory of a made-up paper claiming eating chocolate could enhance weight loss efforts.

But, as the Karl et al. paper (as well as the other recent papers linked above) shows, some climate scientists are pushing forward with less than robust results anyway.

Why? Here’s a possible clue.

Recall an op-ed in the New York Times a few months back by Naomi Oreskes titled “Playing Dumb on Climate Change.” In it, Oreskes, a science historian (and author of the conspiratorial Merchants of Doubt) argued that since climate change was such an urgent problem, we shouldn’t have to apply the same 1-in-20 set of rigorous statistics to the result—it is slowing down the push for action. Climate scientists, Oreskes argued, were being too conservative in face of a well-known threat and therefore, “lowering the burden of proof” should be acceptable.

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