If you live in a college town, you may have seen protesters Sunday and wondered what they were protesting.

Probably this, as pictured by Weasel Zippers …

… and reported by John Fund:

All day Sunday, they filled the streets of Manhattan for a march that featured Al Gore, New York City mayor Bill de Blasio, and various Hollywood actors.

But they certainly didn’t act like a movement that was winning. There was a tone of fatalism in the comments of many with whom I spoke; they despair that the kind of radical change they advocate probably won’t result from the normal democratic process. It’s no surprise then that the rhetoric of climate-change activists has become increasingly hysterical. Naomi Klein, author of a new book on the “crisis,” This Changes Everything: Capitalism vs. the Climate, said, “I have seen the future, and it looks like New Orleans after Hurricane Katrina.” In her new book she demands that North America and Europe pay reparations to poorer countries to compensate for the climate change they cause. She calls her plan a “Marshall Plan for the Earth” and acknowledges that it would cost “hundreds of billions if not trillions of dollars.” But she has an easy solution on how to pay for it: “Need more money? Print some!” What’s a little hyperinflation compared to “saving the planet”?

Nor is Klein alone in her hysteria. Actor Leonardo DiCaprio is releasing a new film in which he warns that the world is threatened by a “carbon monster” that is treated like a kind of Godzilla that must be killed off by ending the use of carbon-based fuels.

One reason the rhetoric has become so overheated is that the climate-change activists increasingly lack a scientific basis for their most exaggerated claims. As physicist Gordon Fulks of the Cascade Policy Institute puts it: “CO2 is said to be responsible for global warming that is not occurring, for accelerated sea-level rise that is not occurring, for net glacial and sea-ice melt that is not occurring . . . and for increasing extreme weather that is not occurring.” He points out that there has been no net new global-warming increase since 1997 even though the human contribution to carbon dioxide in the atmosphere has risen by 25 percent since then. This throws into doubt all the climate models that have been predicting massive climate dislocation.

Other scientists caution that climate models must be regarded with great care and skepticism. Steven Koonin, the undersecretary for science in the Energy Department during President Obama’s first term, wrote a pathbreaking piece in Saturday’s Wall Street Journal in which he concluded:

We often hear that there is a “scientific consensus” about climate change. But as far as the computer models go, there isn’t a useful consensus at the level of detail relevant to assessing human influence. . . . The models roughly describe the shrinking extent of Arctic sea ice observed over the past two decades, but they fail to describe the comparable growth of Antarctic sea ice, which is now at a record high. . . . Any serious discussion of the changing climate must begin by acknowledging not only the scientific certainties, but also the uncertainties, especially in projecting the future. Recognizing those limits, rather than ignoring them, will lead to a more sober and ultimately more productive discussion of climate change and climate policies. To do otherwise is a great disservice to climate science itself.

Even scientists who accept the conventional scientific treatment of the subject by the U.N. International Panel on Climate Change increasingly question just how much it would help to curb emissions or to radically redistribute wealth, as activists like Klein urge us to do. Bjørn Lomborg, director of the Copenhagen Consensus Center, told me that all of the carbon-reduction targets advocated by the U.N. or the European Union would result in imperceptible differences in temperature, at enormous cost. “We would be far better off and richer if we did simple things like painting roofs in hot climates white and investing in new technologies that could help us adapt to any change that is coming,” he says. Even the U.N.’s own climate panel admits that so far, climate change hasn’t included any increase in the frequency or intensity of so-called extreme weather. …

Maybe that’s why the climate-change extremists are basing fewer of their appeals on fact and more on hysteria. You scream the loudest when the opposition is about to tip over on you and pin you down.

Fund quotes climate scientist Roy Spencer:

For many years we had been hearing from the “scientific consensus” side that natural climate change is nowhere near as strong as human-caused warming . . . yet the lack of surface warming in 17 years has forced those same scientists to now invoke natural climate change to supposedly cancel out the expected human-caused warming!

C’mon guys. You can’t have it both ways! They fail to see that a climate system capable of cancelling out warming with natural cooling is also capable of causing natural warming in the first place. . . . To me, it feels like a climate skepticism tipping point has been reached.

Except among the activists, reports The American Interest:

The New York Times has a taste of the rhetoric being bandied about on the ground today:

“I’m here because I really feel that every major social movement in this country has come when people get together,” said Carol Sutton of Norwalk, Conn., the president of a teachers’ union. “It begins in the streets.” […]

“The climate is changing,” said Otis Daniels, 58, of the Bronx. “Everyone knows it; everyone feels it. But no one is doing anything about it.” […]

“Climate change is no longer an environmental issue; it’s an everybody issue,” Sam Barratt, a campaign director for the online advocacy group Avaaz, which helped plan the march, said on Friday.

“The number of natural disasters has increased and the science is so much more clear,” he added. “This march has many messages, but the one that we’re seeing and hearing is the call for a renewable revolution.”

It was the usual post-communist leftie march. That is, it was a petit-bourgeois re-enactment of meaningless ritual that passes for serious politics among those too inexperienced, too emotionally excited or too poorly read and too unpracticed at self-reflection or political analysis to know or perhaps care how futile and tired the conventional march has become. Crazed grouplets of anti-capitalist movements trying to fan the embers of Marxism back to life, gender and transgender groups with their own spin on climate, earnest eco-warriors, publicity-seeking hucksters, adrenalin junkies, college kids wanting a taste of the venerable tradition of public protest, and, as always, a great many people who don’t think that burning marijuana adds to the world’s CO₂ load, marched down Manhattan’s streets. The chants echoed through the skyscraper canyons, the drums rolled, participants were caught up in a sense of unity and togetherness that some of them had never known. It was almost like politics, almost like the epochal marches that have toppled governments and changed history ever since the Paris mob stormed the Bastille.

Almost. Except street marches today are to real politics what street mime is to Shakespeare. This was an ersatz event: no laws will change, no political balance will tip, no UN delegate will have a change of heart. The world will roll on as if this march had never happened. And the marchers would have emitted less carbon and done more good for the world if they had all stayed home and studied books on economics, politics, science, religion and law. Marches like this create an illusion of politics and an illusion of meaningful activity to fill the void of postmodern life; the tribal ritual matters more than the political result. …

In the annals of serious climate policy, however, an explosive essay landed in the Wall Street Journal this past Friday. Titled “Climate Science Is Not Settled“, it will have more impact than anything said or chanted by the misguided marchers. Its author, Dr. Steven A. Koonin, was the Undersecretary for Science in the Energy Department during President Barack Obama’s first term. Dr. Koonin argues that while certain things about the climate are in fact settled science, there is much that is still disputed among climate researchers. A taste:

The crucial scientific question for policy isn’t whether the climate is changing. That is a settled matter: The climate has always changed and always will. Geological and historical records show the occurrence of major climate shifts, sometimes over only a few decades. We know, for instance, that during the 20th century the Earth’s global average surface temperature rose 1.4 degrees Fahrenheit.

Nor is the crucial question whether humans are influencing the climate. That is no hoax: There is little doubt in the scientific community that continually growing amounts of greenhouse gases in the atmosphere, due largely to carbon-dioxide emissions from the conventional use of fossil fuels, are influencing the climate. There is also little doubt that the carbon dioxide will persist in the atmosphere for several centuries. The impact today of human activity appears to be comparable to the intrinsic, natural variability of the climate system itself.

Rather, the crucial, unsettled scientific question for policy is, “How will the climate change over the next century under both natural and human influences?” Answers to that question at the global and regional levels, as well as to equally complex questions of how ecosystems and human activities will be affected, should inform our choices about energy and infrastructure.

But—here’s the catch—those questions are the hardest ones to answer. They challenge, in a fundamental way, what science can tell us about future climates.

It is this uncertainty about accurately predicting future outcomes, on both the local and aggregate levels, that makes sound policy decisions almost impossible:

Policy makers and the public may wish for the comfort of certainty in their climate science. But I fear that rigidly promulgating the idea that climate science is “settled” (or is a “hoax”) demeans and chills the scientific enterprise, retarding its progress in these important matters. Uncertainty is a prime mover and motivator of science and must be faced head-on. It should not be confined to hushed sidebar conversations at academic conferences.

Society’s choices in the years ahead will necessarily be based on uncertain knowledge of future climates. That uncertainty need not be an excuse for inaction. There is well-justified prudence in accelerating the development of low-emissions technologies and in cost-effective energy-efficiency measures.

But climate strategies beyond such “no regrets” efforts carry costs, risks and questions of effectiveness, so nonscientific factors inevitably enter the decision. These include our tolerance for risk and the priorities that we assign to economic development, poverty reduction, environmental quality, and intergenerational and geographical equity.

Individuals and countries can legitimately disagree about these matters, so the discussion should not be about “believing” or “denying” the science. Despite the statements of numerous scientific societies, the scientific community cannot claim any special expertise in addressing issues related to humanity’s deepest goals and values. The political and diplomatic spheres are best suited to debating and resolving such questions, and misrepresenting the current state of climate science does nothing to advance that effort.

All of this is so very spot on—and so refreshing coming from a former Obama Administration official. We can’t encourage you enough to read the whole thing.

One thing we would add to the Koonin essay is that the rapidly developing information revolution is already contributing to declining carbon emissions in countries like the United States and the potential for changing technologies to create a cleaner, less energy-intensive economy is becoming more evident all the time. Fixing the environment isn’t about donning hair shirts and eating granola; it’s about harnessing the marvelous technological breakthroughs that will allow us and our descendants to live richer and more abundant lives on a more flourishing planet.