10 Frequently Heard Claims Made by Climate Deniers and Whether They’re True or Not

A YouGov poll in 2019 showed that 17 percent of Americans believed that “the idea of man-made global warming is a hoax that was invented to deceive people.” Among respondents to the survey who described their political views as “very right-wing,” more than half (52 percent) said that global warming was just a big hoax. Even a U.S. president, Donald Trump, has ridiculed climate change as a hoax.

Suffice to say, if anthropogenic climate change is all a giant hoax, it must be the most cleverly designed, widely spread hoax in history, fooling even the most brilliant scientific minds. Pretty much every significant scientific organization in the world—from the Royal Flemish Academy of Belgium for Sciences and the Arts to Britain’s Royal Society—affirms the reality of human-made climate change.

It’s not just scientists. Some oil companies, including BP and Shell Oil, have issued public statements affirming the “increasing consensus that climate change is linked to the consumption of carbon based fuels.”

This argument, often referred to as the “internal variability” of climate, has been addressed in repeated studies by climate scientists. Their results have shown that while internal variability is of course a real thing, it can account for no more than a fraction of the global warming recorded over the past century—the most recent four decades in particular.

In addition, the “internal variability” advocates find themselves in a Catch-22. If natural changes account for most warming, then the climate’s sensitivity to increased levels of carbon dioxide must be low. After all, CO2 levels are 50 percent higher now than before the industrial era began. But how can the climate be even more sensitive to internal forces than anyone previously believed, but at the same time much less sensitive to external factors, namely CO2? The climate deniers don’t say.

No less a luminary than Texas Republican Senator Ted Cruz has made this claim, saying the often-stated figure of 97 percent of climate scientists who agree that humans drive climate change is “based on one discredited study.” The Fraser Institute, a think tank financed by (among others) the Charles Koch Foundation—a major donor to right-wing nonprofits—has also been active in attempts to deny that climate scientists widely agree on anthropogenic climate change.

As outlined above, multiple reviews of thousands of published papers have shown agreement in the neighborhood of 97 percent that human activity is the leading cause of the climate crisis. In addition to those cited earlier, two studies in 2021 also found 98 or 99 percent consensus in favor of anthropogenic climate change.

No one’s saying that CO2 is a bad thing. In fact, it’s an absolutely necessary thing. Some level of greenhouse gas is essential because it traps the sun’s heat. Oxygen and nitrogen, which account for 99 percent of the atmosphere, are unable to do that. Without CO2, the planet would freeze. Even the small portion of CO2 in the atmosphere is enough to keep the Earth warm.

The problem comes when there is too much carbon dioxide. That’s where we are now, with higher levels of CO2 in the air than any other time since human beings have walked the Earth, and the planet is fast becoming too warm as a result.

Nature pumps carbon dioxide into the atmosphere—but also pulls it out. Carbon “sinks” such as oceans and forests absorb more CO2 from the air than they put back. But since humans began burning fossil fuels for energy, more CO2 is spewed into the atmosphere than naturally occurring carbon sinks can hold, while humans do basically nothing to take out the carbon dioxide we put in.

On Feb. 26, 2015, Oklahoma Republican Senator James Inhofe—who was one of the most vocal climate deniers in Congress—appeared on the floor of the Senate holding a snowball. “We keep hearing that 2014 has been the warmest year on record,” Inhofe said. “Do you know what this is? It’s a snowball just from outside here. So it’s very, very cold out. Very unseasonable.”

He was right. It was cold outside in Washington, D.C., that day. But that has nothing to do with climate change. “Climate” refers to the long-term characteristics of the atmosphere. What Inhofe was talking about, whether he understood it or not, was “weather,” which describes short-term atmospheric conditions, generally in a single location. Even if it’s cold outside where you live, the average temperature of the Earth still remains high.

Even as the planet heats up, winter weather is still a thing. At the same time, winters have become milder. Since 1990, most of the U.S. has avoided extreme cold in the winter months. In any given winter, extreme cold—that is, temperatures in the bottom 10 percent of all those ever recorded—have affected only about 10 percent of the country's area, according to the National Oceanic and Atmospheric Administration (NOAA). In the decade of the 2000s that percentage was near zero.

This popular climate-denier point may be the biggest red herring of them all. As explained in the previous entry, there is a difference between climate and weather. Your local meteorologist’s job is to tell you what the weather will be like—rain or snow, sunny or cloudy, etc.—today, or tomorrow, or 10 days from now. And for the most part, they do a really good job.

Of course, sometimes they get it wrong. According to the NOAA, five-day weather forecasts are correct about 90 percent of the time. The percentage drops to 80 for seven-day forecasts and all the way to 50 percent for predicting the weather 10 days or more in the future.

The job of a climate scientist, however, is not to tell you to expect intermittent thundershowers on July 27, 2055. Climate models predict the average temperature of large areas—the entire planet, for example—over lengthy periods of time. Because they’re so general, climate changes are easier to predict than weather. One prediction climate scientists are finding very easy to make: the planet will keep getting hotter.

While many climate denier arguments may seem silly, designed to get people discussing anything other than what’s actually happening to the climate, this one is a bit trickier. If you can invoke the Second Law of Thermodynamics with authority, you must know what you’re talking about. Right? 

The Second Law of Thermodynamics is often stated as “entropy always increases, never decreases.” For the purposes of a climate change debate, however, it can be said to mean that heat travels from a hotter object to a colder one, never the other way around. According to opponents of climate change theory, that means greenhouse gases in the atmosphere cannot cause the Earth to heat up, because the gases are always cooler than the planet’s surface. What climate scientists call the “greenhouse effect” simply cannot happen under this misreading of the accepted laws of physics. 

The popularity of the “Second Law” claim derives from a 2007 academic paper rather dryly titled “​​Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics,” by Gerhard Gerlich and Ralf D. Tscheuschner, two German physicists—though neither a climate scientist. Actual climate scientists have published refutations of the paper and its thesis, but the most important point is a basic one. Greenhouse gases are not what heats the Earth’s surface.

The “greenhouse effect” is caused by carbon dioxide and other gases trapping heat that rises from the planet’s surface and would otherwise escape into space. The Earth’s own heat causes the planet to warm—which is fully consistent with the Second Law of Thermodynamics. As one commenter noted, if Gerlich and Tscheuschner were right, they would have also proved that “blankets can’t keep you warm at night.”

Inhofe, who retired from the Senate at the start of 2023, was not only the most outspoken climate-denier of any American elected official—he was once described as “the original climate-denier in chief … one of the first people spouting this gibberish.” He was also the chair of the Senate Environment and Public Works Committee for several years, so his statements on the subject carried some weight. Why was he so adamant about denying the reality of climate change? Because, he believed, only God can change the climate.

“Man can’t change climate,” he said in one of his more infamous addresses on the subject. “God’s still up there. The arrogance of people to think that we, human beings, would be able to change what He is doing in the climate is to me outrageous.”

It’s true that there is little humans can do to change the weather. People can’t stop a tornado or a tsunami. But as decades of climate research has shown, there is plenty that human beings can do, and actually are doing, to change the climate—burning petroleum and releasing the resulting CO2 foremost among them.

Other human activities also have a direct effect on the climate. Deforestation increases the CO2 in the atmosphere. Chlorofluorocarbons, or CFCs, despite being internationally banned in the 1980s, remain in the atmosphere and are one of the most efficient greenhouse gases. And there are many more examples. 

Debating God’s role in climate change is better left to theologians, but the fact that humans are powerful enough to affect the planet’s climate is well-documented.

People who make this argument accept that climate change is happening, and that humans cause it. But they believe that the dangers have been wildly exaggerated, so exaggerated that we don’t need to do much about it. Just chill out, everybody.

The reality is, humans have already burned so much fossil fuel and deposited such a large amount of CO2 and other greenhouse gases into the atmosphere that even if we took immediate action to cut emissions, it could still take 30 years or more before global warming shows signs of slowing down.

The planet’s temperature, and most importantly the temperature of the oceans that cover 70 percent of the Earth’s surface, has been rising steadily since 1880 and really gained steam in the 1990s. The 10 hottest years on record have all come since 2010, according to the NOAA. There’s no reason to think this trend will reverse on its own without concerted human effort.

What happens if we just ignore it? Scientists have differing predictions. Christiana Figueres and Tom Rivett-Carnac, architects of the 2015 Paris Accords, have put forth a “worst case scenario” in which by the year 2050 you wouldn’t be able to go outside or even open a window without first checking the air quality. Wearing an industrial-quality mask will become a necessity on many days. In some areas, temperatures could average 140 degrees Fahrenheit for as long as a month at a time.

On the other hand, there are plenty of experts who aren’t quite as pessimistic. Penn State atmospheric science professor Michael Mann says he doesn’t think the extreme scenario is “likely.” But he adds, “there is much more that needs to be done.”

Back in the 1960s and ’70s, climate science was not the organized discipline that it is today. It is true that in that era, about 10 percent of published research papers on the subject predicted a global cooling trend. Somehow, this small percentage gave rise to a persistent myth of a  scientific consensus 50 years ago that a “new Ice Age” was “imminent.”

There was no such consensus. In 2008 scientists from the NOAA and similar organizations conducted a review of scientific literature from the ’70s and found that papers predicting global warming were six times more common than those supporting the “cooling” hypothesis.

An April 28, 1975, cover story in Newsweek by science editor Peter Gwynne played a big part in perpetuating the myth. Gwynne himself later said he regretted the story, but that hasn’t stopped climate deniers from the late Rush Limbaugh to Donald Trump himself from gleefully citing the story as proof that scientists were once in agreement on “global cooling.”

They never were.