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.”


Back in the Bush II Administration, the American Association for the Advancement of Science (AAAS) nakedly tried to nudge the political process surrounding the passage of the environmentally‐​horrific ethanol fuel mandate. It hung a large banner from the side of its Washington headquarters, picturing a corn stalk morphing into a gas pump, all surrounded by a beautiful, pristine, blue ocean. They got their way, and we got the bill, along with a net increase in greenhouse gas emissions.


So it’s not surprising that AAAS is on the Washington Insider side of global warming, releasing a report today that is the perfect 1–2‑3 step‐​by‐​step how‐​to guide to climate change alarm.


This is how it is laid out in the counterfactually‐​titled AAAS report  “What We Know”:


Step 1: State that virtually all scientists agree that humans are changing the climate,


Step 2: Highlight that climate change has the potential to bring low risk but high impact outcomes, and


Step 3: Proclaim that by acting now, we can do something to avert potential catastrophe.


To make this most effective, appeal to authority, or in this case, make the case that you are the authority. From the AAAS:

We’re the largest general scientific society in the world, and therefore we believe we have an obligation to inform the public and policymakers about what science is showing about any issue in modern life, and climate is a particularly pressing one,” said Dr. Alan Leshner, CEO of AAAS. “As the voice of the scientific community, we need to share what we know and bring policymakers to the table to discuss how to deal with the issue.

But despite promising to inform us as to “what the science is showing,” the AAAS report largely sidesteps the best and latest science that points to a much lowered risk of extreme climate change, choosing instead to inflate and then highlight what meager evidence exists for potential catastrophic outcomes—evidence that in many cases has been scientifically challenged (for example here and here).

The AAAS takes us through the standard litany of scare‐​scenarios and tipping points. If you can imagine it, the AAAS mentions it. Rapid sea level rise? Check. Heat waves, floods, droughts? Check. Check. Check. Deteriorating public health? Check. National security threat? Check. Ecological collapse? Check. And the list goes on. 


The AAAS’s justification for such alarm?

Below are some of the high‐​side projections and tail risks we incur by following the current path for CO2 and other greenhouse gas emissions. Most of these projections derive from computer simulations of Earth and its climate system. These models apply the best understanding science has to offer about how our climate works and how it will change in the future. There are many such models and all of them have been validated, to varying degrees, by their ability to replicate past climate changes.

Somehow in its haste to scare us, the AAAS seems to have missed (or ignored) the two hottest topics in climate change these days—1) that climate models have done remarkably poorly in replicating the evolution of global temperature during the past several decades , and 2) that high end climate change scenarios from the models are largely unsupported by observations.


Thus, “what the science is showing” completely undermines the AAAS contentions regarding alarming climate change.


So here’s what we are left with.


As to the AAAS’s first point that human actions are causing climate change, this is largely correct, although the degree and details—the most important features—are uncertain and still being intensity studied and debated (a fact left out by the AAAS).


As to the second point, the current best science suggests that coming human‐​caused climate change is going to be less than expected with a much‐​diminished risk of abrupt changes with catastrophic outcomes (a fact left out by the AAAS).


Which means that the AAAS’s third point, that immediate action is required to reduce the risk of extreme change, is hardly applicable—especially when recognizing that no matter what action we take in the U.S. (the primary audience of the AAAS report) it will have such a small impact on the course of future climate change as to do nothing to alleviate the overblown worries of the AAAS (a fact left out by the AAAS).


Add this all up and you realize that the AAAS report is the epitome of climate alarmism—long in hype and short in fact and aimed squarely at influencing policymakers. We should expect better, but they drank the ethanol years ago.