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Dear Global Warming Skeptics,

2011 April 14

You are in increasingly good company. According to Gallup’s latest annual Environment poll, conducted March 3-6, only 49% of Americans believe that the effects of global warming have already begun, down from a high of 61% in ‘08. Only 52% feel that pollution from human activities is the main culprit. A mere 55% think that most scientists believe global warming is occurring.


Yes, “Climategate” was a disgrace, and far too many folks were overly dismissive of the researchers’ actions. After examining all of the 1,073 e-mails involved, the Associated Press found that the Climate Research Unit “stonewalled skeptics and discussed hiding data.” But this is evidence only that Phil Jones and his three climatologist collaborators should be shamed for being so selective and biased in their presentation of data; it is not evidence that global warming is a hoax. Both the Associated Press and found that this incident in no way detracts from the Intergovernmental Panel on Climate Change’s 2007 report. That report had many contributors: over 2,500 expert reviewers and over 450 lead authors, of whom Phil Jones was one. Additionally, this was the fourth IPCC report: Jones was involved in the third report, but played no part in the first or second.

Jones’ crew may have been poor scientists, but they didn’t single-handedly fabricate the concept of global warming, nor has their blemish distorted the big picture.


The Global Warming Petition Project claims that “31,487 American scientists have signed this petition, including 9,029 with PhDs.” They offer a 12-page review of the literature, which looks legitimate, but one has to wonder: if it convincingly contradicted the internationally accepted notion of global warming, wouldn’t they have been able to get it published in a journal a bit more fitting for its subject matter than the Journal of American Physicians and Surgeons? Further, assuming the petition project is honest about confirming the credentials of their signers, what are their prerequisites? Who cares what most scientists think about global warming when most scientists aren’t climatologists?

Ideally, we could tally the opinions of a wide cross-section of active climatologists, publishing their findings in respected journals featuring developments in earth science. Fortunately, this task has already been undertaken and published in The Proceedings of the National Academy of Sciences:

Although preliminary estimates from published literature and expert surveys suggest striking agreement among climate scientists on the tenets of anthropogenic climate change (ACC), the American public expresses substantial doubt about both the anthropogenic cause and the level of scientific agreement underpinning ACC… Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.


Every winter we see pundits knee-deep in a blizzard, laughing at so-called “Global Warming,” or a comic similarly implying that extreme weather discredits global warming.

Heavy snowfall, if it has anything to do with global warming, might actually support the theory.  Warmer winters mean more evaporating water, thus more snowfall when the air temperature is below freezing, an effect that would be greatest around lakes (not only would there be more nearby water to evaporate, but also less freezing on the lake would have a synergistic effect by decreasing the reflection of the sun’s rays and increasing absorption). The Great Lakes area, then, would make a great coalmine canary for the US. And, in fact such a trend was established at least as early as 2003.

The record colds are a bit trickier. In the case of errant anomalies, we can chalk it up to fluctuation. If, in October, I told you “it’s gonna get colder before it gets warmer,” you would accept that as truth, and if the next day was quite warm, your belief in the overall trend would not falter. So too should a single year be seen among decades of gradual warming.

But the past two winters have both been abnormally cold for Europe. A trend? Too early to call it on repetition alone, but recent research suggests that it may continue, due in part to the Hudson Bay and Baffin Bay (now largely ice-free in November) affecting local weather patterns. If supported by future years’ data and further research, this would not detract from the credibility of global warming, considering annual global averages are still on the rise. In fact, 2010 tied 2005 for the warmest year on record. The polar ice caps really are melting, faster than models predicted.


Understanding why active climatologists are almost unanimously in agreement that the gradual warming over the past handful of decades is due to human influence is, fortunately, quite simple.

Greenhouse gasses keep the earth warm. The greenhouse effect is not up for debate; it’s an established phenomenon. Increase the density of greenhouse gasses in our atmosphere and it stands to reason that the earth will get warmer. Humans are increasing the density of greenhouse gasses in our atmosphere. That’s it.

According to Rebecca Lindsey at NASA, the 0.7 degrees Celsius rise in temperature over the past century is a full eight times faster than scientists estimate the earth warmed on average when recovering from an ice age (ice age recovery being the fastest the earth ever warmed before human influence). This would be a very convincing reason to implicate human influence even if we were currently recovering from an ice age.

The second reason that scientists think the current warming is not from natural influences is that, over the past century, scientists from all over the world have been collecting data on natural factors that influence climate—things like changes in the Sun’s brightness, major volcanic eruptions, and cycles such as El Niño and the Pacific Decadal Oscillation…

The following graph depicts the data from these models, the blue line showing expected changes in temperature based only on natural events, the red line adding human influence to the equation. The accuracy of these models is verified—at least to some extent—by their response to four 20th-century volcanoes, all noted on the graph. The dotted gray line represents actual measurements.

So, based on simple addition we can expect our greenhouse gas emissions to raise the earth’s temperature, which has been rising far faster than we could expect it to even if we were recovering from an ice age, and we have models in place to account for human activity that have done a pretty solid job of mirroring (and thus confirming explanations of) actual measured temperatures.


Believing that humans are responsible for global warming isn’t enough. We need to be scared. According to the Gallup poll, only 51% of Americans worry about it at least “a fair amount,” down from 66% in ’08.

Perhaps the most significant object of concern is a substantial, growing body of evidence predicting severe, long-term draught. Precipitation might increase in certain areas near water during the winter, but overall, water will become a far larger problem than it already is, not to mention decreased soil quality. This and other factors will have a deleterious effect on farming, and send an unpredictable ripple effect throughout our ecosystem. Those who think that the Earth’s flora and fauna will “evolve and adapt” have a very mistaken view of the time constraints under which evolution is capable of lending its unpredictable aid.

If you’ve remained skeptical this long, you might be thinking that this isn’t incontrovertible proof. Sure, it’s not. But if the predictions of severe draught are at least somewhat accurate, we only have to wait a handful of decades for verification. Isn’t this the sort of scenario where it’s best to play it safe?

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