In what’s become an annual tradition in the Colorado General Assembly, Democrats in the majority are spending the final weeks of the legislative session passing bills aimed at reducing greenhouse gas emissions, while their Republican colleagues persist in outright denial of the scientific consensus on manmade climate change.

Senate Bill 23-16, which would set new targets for greenhouse gas emissions cuts while boosting clean energy and carbon-capture efforts, was given initial approval by the House on Wednesday evening — but not before Colorado GOP lawmakers reiterated their rejection of mainstream climate science.

In a nearly hourlong speech in opposition to the bill, state Rep. Ken DeGraaf, a Colorado Springs Republican, offered a grab-bag of debunked climate-denial talking points and half-truths, rehashing decades-old myths as he described concern over carbon dioxide’s role in global warming as “hysteria around a trace gas.”

“Carbon dioxide, god bless it — great for growing plants, but does really very little in terms of greenhouse gas,” DeGraaf said in his speech on the House floor.

It was the latest in a long series of reminders that GOP lawmakers remain committed to all-out climate misinformation as they battle Colorado Democrats’ clean-energy agenda at the Capitol.

“The crisis that we have is to spend as much money on the green energy cartel before everybody becomes aware that it’s not a real threat,” added DeGraaf.

In 2021, GOP Senate Minority Leader Chris Holbert said of “so-called climate change” during a floor debate on an environmental justice bill that he did “not believe that it is man-made.” State Sen. Barbara Kirkmeyer, who lost narrowly last year to Democratic U.S. Rep. Yadira Caraveo in the race for the new 8th Congressional District, falsely claimed during her campaign that “to what extent any warming is a result of man-caused activity is unknown.”

In fact, climate scientists with the Intergovernmental Panel on Climate Change say that the Earth has warmed at an unprecedented rate since 1850, and the evidence of human influence is “unequivocal.”

“Evidence is overwhelming that the climate has indeed changed since the pre-industrial era and that human activities are the principal cause of that change,” concluded the IPCC’s 2021 report on the physical science of climate change, which was authored by 234 scientists from around the world and compiled the results of thousands of studies conducted over many decades.

SB-16, which had been poised to win final passage in the full House this week, would commit Colorado for the first time to achieving net-zero greenhouse gas emissions by 2050, revising the state’s current target up from a 90% reduction by that date, and setting other interim emissions goals.

“We know we need to get to 100%,” said state Rep. Karen McCormick, a Longmont Democrat, one of the bill’s House sponsors, during Wednesday’s floor debate. “We really need to set these goals out there, so that we’re aiming to get them, and having interim targets makes sure we’re on track.”

Denialist talking points

Telling his fellow lawmakers that he had “been studying this stuff for a long time,” DeGraaf read at length from printed material authored by prominent climate deniers and skeptics, including Judith Curry and Howard Hayden. Curry is a former atmospheric scientist with the Georgia Institute of Technology and Hayden, a Pueblo resident, is a retired physics professor who has self-published a number of books denying the science of climate change, including “Bass Ackwards: How Climate Alarmists Confuse Cause with Effect.”

DeGraaf began his speech with one of the most frequently repeated talking points in climate-denial circles.

“Fifty years ago we were talking about global cooling, and now we’re talking about climate change,” he claimed.

A 2008 paper published by the American Meteorological Society called the past existence of a global-cooling consensus a “pervasive myth.” The hypothesis attracted only scant news coverage in the 1970s and was not at any point embraced by the scientific community at large. One of the most widely circulated claims involving global cooling — a purported Time Magazine cover warning of a “coming Ice Age” — is a hoax.

State Rep. Richard Holtorf, an Akron Republican, joined DeGraaf in denouncing the bill and repeating the global-cooling myth, arguing that “none of these predictions will come true, as they haven’t come true in the last 50 years.”

DeGraaf also argued that variations in solar radiation, rather than greenhouse gas emissions, have been responsible for the global temperature increases recorded over the last two centuries. In fact, the IPCC concluded again in 2021 that there has been “negligible long-term influence from solar activity” since 1900.

And DeGraaf’s repeated claim that global warming is driven by water vapor, rather than carbon dioxide and other greenhouse gases emitted by human activity, is another assertion that has been widely shared among conservatives on social media and consistently debunked by climate scientists.

“Without the water vapor, global warming is a nonstarter,” DeGraaf said. “That’s the actual climate science. It’s water vapor.”

Water vapor makes up about 4% of the Earth’s atmosphere. Because it stores heat, it can be considered a greenhouse gas, and the potential for feedback loops caused by rising temperatures and a wetter atmosphere is an important factor in the climate models used by scientists to make long-term global warming projections.

But climatologists say there is overwhelming evidence that the “radiative forcing” of rising atmospheric concentrations of gases like carbon dioxide and methane is the primary driver of global warming. A researcher told AFP in 2021 that water vapor’s categorization as a greenhouse gas is “a great example of the practice of trying to confuse the public with information that is true but totally irrelevant.”

In February, DeGraaf, a first-term lawmaker who was elected in House District 22 last year, introduced a bill that would have “prohibit(ed) the classification of carbon dioxide as a pollutant” in Colorado. The bill was defeated in the House Energy and Environment Committee, with all three of the committee’s Republicans voting in favor.

Rising global temperatures are the main driver of an ongoing “megadrought” in the Colorado River Basin more severe than any dry spell the region has experienced in at least the last 1,200 years, scientists say. Warmer, drier conditions have increased wildfire risk, and all of the 20 largest wildfires in Colorado history have occurred since 2000.

SB-16 contains provisions aimed at boosting decarbonization efforts across a wide variety of industries, including tax incentives for electric-powered lawn equipment; measures to accelerate the construction of electricity transmission infrastructure and rooftop solar installation; stricter requirements on large insurance companies to assess climate risk; and more authority for state regulators to oversee carbon-capture projects.

“There’s probably something in here for everyone,” McCormick said Wednesday. “If you look, you’re going to find a section that you like.”

If passed by the House, the amended SB-16 would need to return to the Senate for a final vote before heading to Gov. Jared Polis for his signature.

This article originally appeared in Colorado Newsline, which is part of States Newsroom, a network of news bureaus supported by grants and a coalition of donors as a 501c(3) public charity. Colorado Newsline maintains editorial independence. Contact Editor Quentin Young for questions: [email protected]. Follow Colorado Newsline on Facebook and Twitter.