What Isn't the Weatherman Telling You?

John Coleman is a TV weathercaster, best known for being one of the founders of The Weather Channel. Nowadays he hangs out at KUSI-TV in San Diego, where he has recently taped a segment on the great hoax of global warming. Coleman's credentials make him a hero of global warming skeptics, but don't confuse him with The Weather Channel itself. The Weather Channel's official position is that greenhouse gas emissions are causing a "significant warming trend":

The potential exists for the climate to reach a "tipping point," if it hasn't already done so, beyond which radical and irreversible changes occur.

They are very careful about not predicting too much, but their statement is 180 degrees different from Coleman's video clip.

Coleman's disagreement with the scientific consensus on climate change has been known for some time. As a result, he has said many things that are flat wrong. (Click here for examples.)  

How can such an eminent meteorologist make such egregious errors? It helps to understand---and this is in no way an insult toward meteorologists--he is not a climate scientist. That may not sound like a big difference, but it is. Meteorologists certainly understand weather patterns better than the average person, but they are not expert researchers. They can interpret and report daily trends, but they are not experts on climate change by any stretch of the imagination. A couple analogies from climate scientist Joseph Romm make the difference very clear:

Asking a meteorologist to opine on the climate — or even the cause of recent extreme weather – is like asking your family doctor what the chances are for an avian flu pandemic in the next few years or asking a mid-West sheriff the prospects for nuclear terrorism. The answer might be interesting, but not one I’d like to stake my family’s life on.

For those of you who have watched the video and are (rightly) confused or concerned or convinced, here are some facts that may help you sort out the truth:

Coleman argues that the relative proportion of carbon dioxide emitted by fossil fuel burning is negligible compared to the natural cycle. The carbon dioxide emitted in the natural carbon cycle (by animals exhaling, for example) is then absorbed one-to-one (by plants inspiring, as Coleman acknowledges). Thus there is a natural balance. The planet does not emit any more carbon dioxide than it can absorb, and the net balance of carbon dioxide hanging around in the atmosphere stays the same. Until humans came along. The data is undeniable: For thousands of years, atmospheric concentration of carbon dioxide stayed relatively flat. Since the Industrial Revolution, it has increased exponentially.

Coleman looks at a graph of global temperature going back through several Ice Ages and concludes, from a quick glance, that the current warming is part of a natural cycle. Four problems: (1) If you actually study the data mathematically, it predicts that Earth should currently be in a cooling period, which means that something is breaking the natural cycle. (2) All the previous warming jumps occurred once every 100,000 years. Today's jump is far too fast to fit the previous cycle. (3) Coleman cleverly ignores the fact that all those cycles occurred in almost perfect lockstep with the variation in carbon dioxide. (4) All those past warming increases occurred back when the Earth was on a slightly different orbit, so they are not comparable to today's situation. Given our current orbit, the present warming increase is not natural.

Coleman claims that Arctic ice really isn't melting. I'm not sure where he's getting his data from, but according to the National Snow and Ice Data Center, global glacier thickness has declined every year for the past 4+ decades. The most recent academic research I've seen was published 2 months ago, and it concluded that Antarctic ice loss has been vaster and faster than the IPCC predicted. Another paper published around the same time found that, based on historical evidence, Antarctica is more sensitive to greenhouse gases than previously thought.

Coleman also claims that solar activity explains the rise in global temperature. Again, I don't know where he gets his data from, but according to the World Radiation Center, solar irradiance has not increased one iota over the past 30 years.

Coleman points to a mid-20th-century flatline in global temperatures, amid strong economic growth, as proof that industrialization doesn't cause warming. However, a climate scientist could tell you that that flatline occurred because of an increase in human particulates and aerosol pollution, which counteracted the carbon dioxide. After pollution regulations and better technology reduced these factors, the trend continued as before.

I won't spend any time refuting his casual reference to the Climategate emails. The scientific consensus on climate change is still very strong and fact-based. For details, click here, here, and here.

Meanwhile, NASA reported November 2009 as the hottest November on record and 2009 as the second-hottest year on record. Two independently published papers found, focusing on different periods in our distant past, that the current consensus may significantly underestimate the potential temperature increase from man-made climate change. The World Meteorological Association found the 2000s to be the warmest decade on record. The latest research suggests that sea levels may rise 3 times more than the IPCC predicted. More than 100 of Europe's leading marine scientists released a report showing that ocean acidification has increased 30% since the Industrial Revolution; if left unchecked, this trend would be disastrous for marine life and food supplies.

As for how it all affects you---and mind you, I'm just giving you a taste from the very latest research---economists find a significant negative relationship between temperature and income (despite what John Mackey might tell you) and predict dangerous effects of climate change for the economy. International relations scholars find a significant link between temperature variation and conflict and use quantitative evidence to predict a 54% increase in armed conflict incidence by 2030. And a joint commission between The Lancet medical journal and University College London found that carbon-related pollution is responsible for 2.5 million premature deaths every year. "Climate change," they concluded, "is the biggest global health threat of the 21st century."

There is still a lot of uncertainty in all of these predictions, and I am not predicting anything myself. Climate change is a complex issue, and it may well turn out to be much milder than the consensus expectation. The evidence, however, does not support John Coleman's extreme denial.