One of the hallmarks of an intellectual, thinking person is the willingness to challenge one's own presumptions. This is something of a rarity these days, and in all candor, there are plenty of people across the social and political spectrum who don't do this, either by inattention or by choice. That's something of a sad thing; people should be curious, and open to new ways of thinking.
When the issue at hand is a matter of science, such as, say, anthropogenic climate change, then it's a matter of course that every conclusion, every idea is open to change given new data, new facts. That's how science works; that's why scientific reports, scientific rhetoric are so full of tentative language. Everything in science is tentative.
Sometimes, though, we hear of someone who has abandoned an untenable position after examining the facts. A case in point would be the Breakthrough Institute's Ted Nordhaus, a former self-described climate catastrophist, who took another look at the data and, yes, changed his mind.
Recently, in an exchange on X, my former colleague Tyler Norris observed that over the years, my views about climate risk have evolved substantially. Norris posted a screenshot of a page from the book Break Through, where Michael Shellenberger and I argued that if the world kept burning fossil fuels at current rates, catastrophe was virtually assured:
Over the next 50 years, if we continue to burn as much coal and oil as we’ve been burning, the heating of the earth will cause the sea levels to rise and the Amazon to collapse, and, according to scenarios commissioned by the Pentagon, will trigger a series of wars over the basic resources like food and water.
Norris is right. I no longer believe this hyperbole. Yes, the world will continue to warm as long as we keep burning fossil fuels. And sea levels will rise. About 9 inches over the last century, perhaps another 2 or 3 feet over the course of the rest of this century. But the rest of it? Not so much.
This is as I've been saying, and writing, for years. Yes, the planet's climate has been warming some, as it has been doing since the last major glaciation ended. There have been some dips and spikes, like the Roman Warm Period and the Little Ice Age, but over the last 13,000 years or so the trend has been towards warming. Yes, human actions do have some influence. But the influence we humans have isn't commensurate with the drastic actions proposed by climate scolds or, as Mr. Nordhaus describes them, climate catastrophists.
Mr. Nordhaus describes his journey along this road to Damascus:
At the time that we published Break Through, I, along with most climate scientists and advocates, believed that business as usual emissions would lead to around five degrees of warming by the end of this century. As Zeke Hausfather, Glen Peters, Roger Pielke Jr, and Justin Richie have demonstrated over the last decade or so, that assumption was never plausible.
There have been some revisionist claims that the reason for the downgrading of business as usual warming assumptions is due to the success of climate and clean energy policies over the last several decades. But five degrees of warming by the end of this century was no more plausible in 2007, when Break Through was published, than it is today. The class of scenarios upon which it was based assumed very high population growth, very high economic growth, and slow technological change. None of these trends individually track at all with actual long term global trends. Fertility rates have been falling, global economic growth slowing, and the global economy decarbonizing for decades.
All of these things are accurate. The assumptions of the radical climate chicken littles were based in large part on assumptions that came from the 1960s and 1970s — population growth being a key factor among them. We now know that the global population of humans is expected to peak at some point in this century, and then to start to decline. As for the decarbonizing of our technologies and enterprises, that has been driven largely by the developed world, and not necessarily out of any concerns for the planetary climate, but out of the desire for economic progress and efficiency; an efficient operation or device is a clean operation or device, be it an electrical power plant or a pickup truck.
We make these advances because they make good economic sense. And, as Mr. Nordhaus now understands, the changing climate is something over which 1) we don't have nearly the control that the climate scolds think we do, and 2) is not proceeding towards any catastrophe that would warrant us surrendering much of our modern, comfortable, high-tech, energy-hungry lifestyles.
Facts are stubborn things. Conclusions, the set of opinions we draw from examining facts, can and should change as we become aware of new facts, new data, new information. That's how science works, and that's how we should work, even if it means changing our mind in issues we have long held to be vital. As the late, great Winston Churchill is reported to have said, a man who never changed his mind, never changed anything. And yet, our government, our news media, our social media, and our commentariat are filled with people who have never changed their minds on anything, ever.
We could all take a lesson or two on this from Ted Nordhaus.
