It’s time to be scientific about global warming, says climatologist Judith Curry.
We’ve all come across the images of polar bears drifting on ice floes: emblematic victims of the global warming that’s melting the polar ice caps, symbols of the threat to the earth posed by our ceaseless energy production—above all, the carbon dioxide that factories and automobiles emit. We hear louder and louder demands to impose limits, to change our wasteful ways, so as to save not only the bears but also the planet and ourselves.
In political discourse and in the media, major storms and floods typically get presented as signs of impending doom, accompanied by invocations to the environment and calls to respect Mother Nature. Only catastrophes seem to grab our attention, though, and it’s rarely mentioned that warming would also bring some benefits, such as expanded production of grains in previously frozen regions of Canada and Russia. Nor do we hear that people die more often of cold weather than of hot weather. Isolated voices criticize the alarm over global warming, considering it a pseudoscientific thesis, the true aim of which is to thwart economic modernization and free-market growth and to extend the power of states over individual choices.
Not being a climatologist myself, I’ve always had trouble deciding between these arguments. And then I met Judith Curry at her home in Reno, Nevada. Curry is a true climatologist. She once headed the department of earth and atmospheric sciences at the Georgia Institute of Technology, until she gave up on the academy so that she could express herself independently. “Independence of mind and climatology have become incompatible,” she says. Do you mean that global warming isn’t real? I ask. “There is warming, but we don’t really understand its causes,” she says. “The human factor and carbon dioxide, in particular, contribute to warming, but how much is the subject of intense scientific debate.”
Curry is a scholar, not a pundit. Unlike many political and journalistic oracles, she never opines without proof. And she has data at her command. She tells me, for example, that between 1910 and 1940, the planet warmed during a climatic episode that resembles our own, down to the degree. The warming can’t be blamed on industry, she argues, because back then, most of the carbon-dioxide emissions from burning fossil fuels were small. In fact, Curry says, “almost half of the warming observed in the twentieth century came about in the first half of the century, before carbon-dioxide emissions became large.” Natural factors thus had to be the cause. None of the climate models used by scientists now working for the United Nations can explain this older trend. Nor can these models explain why the climate suddenly cooled between 1950 and 1970, giving rise to widespread warnings about the onset of a new ice age. I recall magazine covers of the late 1960s or early 1970s depicting the planet in the grip of an annihilating deep freeze. According to a group of scientists, we faced an apocalyptic environmental scenario—but the opposite of the current one.
But aren’t oceans rising today, I counter, eroding shorelines and threatening to flood lower-lying population centers and entire inhabited islands? “Yes,” Curry replies. “Sea level is rising, but this has been gradually happening since the 1860s; we don’t yet observe any significant acceleration of this process in our time.” Here again, one must consider the possibility that the causes for rising sea levels are partly or mostly natural, which isn’t surprising, says Curry, for “climate change is a complex and poorly understood phenomenon, with so many processes involved.” To blame human-emitted carbon dioxide entirely may not be scientific, she continues, but “some find it reassuring to believe that we have mastered the subject.” She says that “nothing upsets many scientists like uncertainty.”
This brings us to why Curry left the world of the academy and government-funded research. “Climatology has become a political party with totalitarian tendencies,” she charges. “If you don’t support the UN consensus on human-caused global warming, if you express the slightest skepticism, you are a ‘climate-change denier,’ a stooge of Donald Trump, a quasi-fascist who must be banned from the scientific community.” These days, the climatology mainstream accepts only data that reinforce its hypothesis that humanity is behind global warming. Those daring to take an interest in possible natural causes of climactic variation—such as solar shifts or the earth’s oscillations—aren’t well regarded in the scientific community, to put it mildly. The rhetoric of the alarmists, it’s worth noting, has increasingly moved from “global warming” to “climate change,” which can mean anything. That shift got its start back in 1992, when the UN widened its range of environmental concern to include every change that human activities might be causing in nature, casting a net so wide that few human actions could escape it.
Scientific research should be based on skepticism, on the constant reconsideration of accepted ideas: at least, this is what I learned from my mentor, the ultimate scientific philosopher of our time, Karl Popper. What could lead climate scientists to betray the very essence of their calling? The answer, Curry contends: “politics, money, and fame.” Scientists are human beings, with human motives; nowadays, public funding, scientific awards, and academic promotions go to the environmentally correct. Among climatologists, Curry explains, “a person must not like capitalism or industrial development too much and should favor world government, rather than nations”; think differently, and you’ll find yourself ostracized. “Climatology is becoming an increasingly dubious science, serving a political project,” she complains. In other words, “the policy cart is leading the scientific horse.”