Most people who deny that human activity is warming the planet just dismiss a massive body of scientific evidence as a big hoax. But there’s a more sophisticated set of climate “skeptics” who make arguments that, at least to the lay ear, sound like they’re grounded in scientific evidence. And because most of us lack the background to evaluate their claims, they can muddy the waters around an issue that’s been settled in the scientific community. So, as a public service, we gathered eight of the most common of these pseudoscientific arguments and asked some serious climate scientists — all working climatologists who have been widely published — to help us understand what makes these claims so misleading. 1. No, the Earth Hasn’t Stopped Warming Since 1998 (or 1996 or 1997) This claim was popularized by “Lord” Christopher Monckton, a prominent British climate “skeptic” with no scientific background who presented himself as a member of the House of Lords until the Parliament published a cease and desist order demanding that he stop. His so-called “research” relies on people’s confusion about the difference between weather, which fluctuates all the time, and climate, which speaks to long-term trends. With some careful cherrypicking of data, you get the argument that there’s been “no global warming for 17 years, 3 months.” What’s going on? “1998 was the warmest year in the last century,” explains Kevin Trenberth, a distinguished senior scientist in the Climate Analysis Section of the National Center for Atmospheric Research. “There was a big El Niño event in 1997 and 1998, and we have a lot of evidence that there was a lot of heat coming out of the ocean at that time. So that’s the real anomaly — the fact that we had what was perhaps the biggest El Niño event on record.” “That’s one of the cherrypicking points for deniers — they take the highest value and then compare it” with lower points in the natural temperature fluctuation we know as “weather.” “If you choose the highest value,” says Trenberth, “then the odds are that all the other values are going to be lower — even in the presence of an overall warming climate.” But the idea that the climate stopped warming at some point goes back even further. In the 1990s, two climatologists, Roy Spencer and Richard Lindzen, published a series of papers hypothesizing that global warming had stopped. Spencer and Lindzen are among the few climate contrarians with real scientific credentials, and have been widely cited by climate skeptics; Spencer has testified at a number of Republican congressional hearings on climate science. Spencer also dismisses the theory of evolution, and has written: “I view my job a little like a legislator, supported by the taxpayer, to protect the interests of the taxpayer and to minimize the role of government.” Of course, none of that matters if their science is sound. But according to John Abraham, a professor of thermal and fluid sciences at the University of St. Thomas School of Engineering, who has published over 130 papers in peer-reviewed journals, it isn’t. “It turns out that they made three serious errors in their data,” he explains. “It took years, and it took a lot of time from other scientists to find these errors in their calculations. In fact, they switched a positive sign for a negative sign in one of their equations.” He adds that while warming has in fact slowed on the earth’s surface, “93 percent of the heat goes into the ocean, and the ocean continues to heat, so people are confusing temperature fluctuations in the atmosphere — the weather — with long-term climate change.” 7 more claims debunked via BillMoyers.com.