Andrew Dessler is as dispassionate as an academic should be — except about things he knows to be beyond dispute. In the first sentence, first chapter, of The Science and Politics of Global Climate Change, that passion shows through.

“Of all the environmental issues that have emerged in the past few decades, global climate change is the most serious, and the most difficult to manage. It is the more serious because of the severity of harms that it might bring.”

The book, which the Texas A&M climatologist authored with Edward Parson of the University of Michigan, is one of the nation’s leading college texts on the subject.

It’s advertised as a “guide to the debate,” but Dessler doesn’t go so far as to assign each side of the debate equal weight. He leaves no doubt that industrial-era pollution is contributing to Earth’s heating.

Certainly, how rapidly climate change might occur and how it will affect life on the planet are matters of conjecture and projection. He does not for instance, blame global warming for the recent spate of killer gulf storms.

But relative to the central issue, carbon dioxide emissions, Dessler says no one should be cowed by any number of distractions. Take the claim that cattle flatulence is just as significant a factor. Methane is a greenhouse gas, yes, but “carbon dioxide is the dominant greenhouse gas by a factor of four.” Additionally, what cattle emit will dissipate after 10 years. The CO2 we are adding to our atmosphere is there for our lifetime.

Don’t be comforted, he said, by cherry-picked data, such as the fact that last year was the coolest in a decade. A “temperature anomaly” chart shows a spike of 1.3 degrees in water surface temperatures since the 1900s, after a relatively constant stretch of 300 years.

For anyone who thinks 1.3 degrees to be a pittance, Dessler points out that the Ice Age was precipitated by a 5-degree drop. And if today’s pace continues, a 4-degree rise over the next century is not out of the question, with coastal areas submerged and life-sustaining freshwater sources like the Himalayan glaciers decimated.

“We’ll look pretty stupid in 100 years if we essentially destroyed the world while we were arguing about tax rates, jobs, Bernie Madoff and rescuing the stock market,” he said.

Not surprisingly, Dessler, a Harvard graduate, occasionally finds pockets of doubt in Aggieland.

One time he faced a hostile audience of petroleum engineers. “This was a crowd of academics who were accusing me of fraud,” he said.

However, he said, by and large people get it. Even the Texas Legislature now is talking about it, and not in the denial mode modeled by Texas’ Aggie-in-chief, Rick Perry.

Bills range from capping the state’s CO2 emissions to cashing in on the business of carbon disposal. Ah, money to be made. Now the climatologists are talking Texas’ language.

Dessler is openly disdainful of the economic scare tactics used by the “do nothing” crowd.

That crowd said, for instance, that dramatic measures to curtail the chlorofluorocarbons eating away the ozone layer would carry catastrophic costs. Wrong.

What those measures brought about was innovation, another word for economic development.

“Once people realize there’s going to be regulation (of greenhouse gases) there’s going to be innovation,” he said.

“Climate change is tougher than other issues, but there’s a lot of evidence that people exaggerate the costs of the solution to scare people into inaction.”

The question: Will we say, “Ah, let’s adjust to a warmer planet”? Or will we say, “Let’s adjust our economy and our consumptive lifestyles to lessen our imprint on the planet’s future”?

Which?

John Young’s column appears Thursday and Sunday. E-mail: jyoung@wacotrib.com.