In their desperation to find even a tiny shred of peer-reviewed science to challenge the volumes of research from around the world about human-caused climate change, deniers have often held up Willie Soon's work.

Dr. Soon, an astrophysicist at the Harvard-Smithsonian Centre for Astrophysics, is known for studies that purportedly show that the sun, and not CO2 emissions from human activity, is the main factor in climate change, and that climate change in the 20th century wasn't that unusual to begin with. He has also argued that mercury emissions from burning coal are no big deal.

Now, in response to a Greenpeace investigation, Dr. Soon has admitted that U.S. oil and coal companies, including ExxonMobil, the American Petroleum Institute, Koch Industries, and the world's largest coal-burning utility, Southern Company, have contributed more than $1 million over the past decade to his research. According to Greenpeace, every grant Dr. Soon has received since 2002 has been from oil or coal interests. This despite the fact that he once told a U.S. Senate hearing that he had not been hired by, employed by, or received grants from any organization "that had taken advocacy positions with respect to the Kyoto protocol or the UN Framework Convention on Climate Change."

Dr. Soon has also been affiliated with a number of industry front groups, including the coal-funded Greening Earth Society, and Koch-Exxon-Scaife-funded groups including the George C. Marshall Institute, the Science and Public Policy Institute, the Center for Science and Public Policy, the Heartland Institute, and Canada's Fraser Institute.

Correspondence uncovered by Greenpeace also found that Dr. Soon led a plan in 2003 to undermine the Intergovernmental Panel on Climate Change's Fourth Assessment Report years before it was even released in 2007.

It's not news that the fossil fuel industry has funded an ongoing campaign of doubt and misinformation about the effects of its products and about the dangers of climate change -- people and organizations from science historian Naomi Oreskes (author of Merchants of Doubt) to Greenpeace have been exposing these efforts for years. From hiring trolls and front groups to post comments on websites, submit letters to editors, and write opinion columns to sponsoring "scientific" research and holding conferences, it's all been well documented. (The same tactics have also been used by the tobacco industry.)

The latest revelation is a bit of an embarrassment for oil giant Exxon, though. The world's largest oil company had admitted that it funded these efforts but promised in 2008 it would stop giving money to groups that lobbied against the need to find clean energy sources.

It's also an embarrassment for those who, in the face of overwhelming scientific evidence, deny the existence of climate change -- or admit that it's happening but say we can't and shouldn't do anything about it. Of course, they will continue to repeat the same discredited points about "climategate" and medieval warm periods and CO2 as plant food, and they'll continue to take the advice of industry shills like Tom Harris to bombard the media with opinion articles and letters to editors and to post numerous comments under online articles.

Some rightly point out that we should look at the science and not at who is paying for the research. So what about Dr. Soon's science? Well, let's consider one paper that Dr. Soon published with colleague Sallie Baliunas, which attempted to discredit the work of Michael Mann, director of the Earth System Science Center at Pennsylvania State University. Three editors of the publication that ran the study resigned in protest, including incoming editor-in-chief Hans von Storch. He said "the conclusions [were] not supported by the evidence presented in the paper." Greenpeace notes also that 13 of the scientists cited in the paper published rebuttals stating that Dr. Soon and Dr. Baliunas had misinterpreted their work.

After all their digging, deniers have only been able to find a few minor errors in the volumes of peer-reviewed science about climate change, and have had to rely on manufactured scandals and conspiracy theories to bolster their arguments. It only takes a bit of investigating to poke holes in the scant bits of research that have attempted to discredit real climate science. Let's stop wasting our time on deniers. It would be better spent trying to resolve the serious problems we have created.

Dr. David Suzuki is a scientist, broadcaster, author, and co-founder of the David Suzuki Foundation. Written with contributions from David Suzuki Foundation editorial and communications specialist Ian Hanington.

This blog was previously published here.

Learn more at www.davidsuzuki.org.