Republican Senate candidate Joni Ernst. CREDIT: AP Photo / Justin Hayworth On Sunday, the Republicans’ Senate candidate from Iowa, Joni Ernst, joined the ranks of politicians who confess to not knowing the science of climate change, but remain happy declaring we need do nothing about it. Ernst, a member of Iowa’s state senate, is going up against Rep. Bruce Braley (D-IA) for one of Iowa’s two seats in the national Senate. The two have been neck-and-neck in the polling, and last night they had their first debate at Simpson College in Indianola, Iowa. At about 41 minutes into the debate one of the moderators told Ernst they had received a number of emails concerning climate change, and asked her, “What do you believe about climate change, and what if anything will you do about it?” Ernst began her response by praising Iowans and in particular Iowa’s farmers for their conservationist streak — a point on which Braley later agreed with her — and pointed out that her own family drives a hybrid car and devoutly recycles. But on the point of climate change specifically, Ernst dodged: “I don’t know the science behind climate change. I can’t say one way or another what is the direct impact, whether it’s man-made or not. I’ve heard arguments from both sides, but I do believe in protecting our environment, but without the job killing regulations that are coming out of the [Environmental Protection Agency] which is what Congressman Braley supports.” “I do believe our climate is changing,” she continued, after being pressed. “But again, I’m not sure what the impact of man is upon that climate change.” Ernst sounded a similar note back in May, saying that “I have not seen proven proof that [climate change] is entirely man-made.” She’s also promised “to abolish” the Environmental Protection Agency, and she opposes the Clean Water Act. A few distinctions might be useful here. While the devotion of Ernst’s family to conservation and recycling is admirable, this makes the mistake of treating climate change as a test of her individual virtue or of anyone’s individual virtue. But climate change is a classic “free rider” problem: any one individual has a natural incentive to keep emitting carbon and not sacrifice to address the problem, because they assume everyone else will. And then no one emits any less carbon. It’s also useful to distinguish between environmentalism generally and climate change specifically. Some environmental issues of pollution or resource use can be dealt with at a local or state level as Ernst prefers. (Though even the flow of water through Iowa’s rivers doesn’t stop at the state’s borders.) But climate change is about the concentration of carbon dioxide in the atmosphere, which we all share. What happens in Iowa affects what happens in Texas and California and Michigan and vice versa. What all this means is that climate change has to be addressed systemically, by policies that coordinate everyone’s response at once. So this means something like a national carbon tax, a national cap-and-trade system, or the more limited regulations of power plants recently put in place by the Environmental Protection Agency (EPA). This is where the science of climate change becomes critically important. If humanity’s carbon emissions are the main driver of the problem, than we know what we have to do and what policies have to be put in place to fix that. If Ernst herself doesn’t know the science, that’s perfectly fair. One can’t be an expert in everything. House Speaker John Boehner (R-OH), Florida Governor Rick Scott (R), and Louisiana Governor Bobby Jindal (R), among others, have all admitted at various times they aren’t qualified to adjudicate the science either. But there are thousands of climate scientists who are qualified. And 97 percent of them agree humanity’s carbon emissions are a big driver of climate change. According to the latest report from the United Nations’ Intergovernmental Panel On Climate Change (IPCC), scientists have found a 95 percent certainty that the vast majority of the global warming observed since the 1950s was manmade. To put that in context, 95 percent is the same certainty level that scientists assign to the assertion that cigarettes can kill you. The IPCC has also determined we only have so march carbon we can still emit before we make at least 2°C of global warming an inevitability. Past that threshold, scientists are pretty sure climate change would become genuinely catastrophic. At the current rate America and the rest of world is emitting carbon, we’ll leave that marker in the dust in relatively short order. In short, the people who do know the science of climate change believe it’s real, that humanity is the key driver, and that if we don’t change our behavior drastically and rapidly, we’re almost certainly going to severely damage the global ecology — and human civilization’s own ability to keep functioning along with it. By this point, Ernst is a well known public figure. It shouldn’t be hard for her to get a climate scientist on the phone. The post Iowa Senate Candidate Joni Ernst Joins The ‘I Don’t Know The Science’ Chorus On Climate Change appeared first on ThinkProgress.