According to the Heartland Institute, a conservative think tank, those who accept the science of climate change are \"on the radical fringe\" with the movements most \"prominent advocates\" being \"murderers, tyrants, and madmen.\" The Heartland Institute\'s statements came as it launched a billboard campaign featuring notorious mass-murderer, Ted Kaczynski also known as the Unabomber, on a billboard in Chicago that read \"I still believe in Global Warming? Do you?\" The Kaczynski billboard remained live for 24 hours before widespread condemnation, including from the Heartland Institute\'s own supporters, pushed the group to pull the billboard. It has now suspended the short-lived campaign which was also going to feature similar billboards with Fidel Castro, Osama Bin Laden, and hostage-taker James J. Lee. \"This is what desperation looks like,\" Jamie Henn with climate advocacy group, 350.org, told mongabay.com. \"Comparing 97 percent of the world\'s scientists, the pope, and the president—all of whom believe in climate change—to mass murderers is a bit unhinged, to put it lightly.\" In a press release that accompanied the short-lived campaign, the Heartland Institute wrote, \"What these murderers and madmen have said differs very little from what spokespersons for the United Nations, journalists for the \'mainstream\' media, and liberal politicians say about global warming,\" adding that \"the people who still believe in man-made global warming are mostly on the radical fringe of society.\" However, everyone of the world\'s major scientific bodies, from NASA to the Royal Society, agrees that the world is warming due to greenhouse gas emission. Most Americans also see a need to tackle climate change. According to a recent poll by the Yale Project on Climate Change Communication, 72 percent of Americans believe that climate change should be a medium to high priority for the Federal government, including 52 percent of Republicans. Henn says that the actions taken by the Heartland Institute is in line with a broader campaign by fossil fuel companies to shed doubt on climate science. \"It\'s to the advantage of the fossil fuel industry and their allies to make this issue as contentious as possible and mire climate action in more partisan gridlock,\" he says, adding that, \"Here in the U.S., seven out of ten Americans think global warming played a part in the weird weather over the last year. We\'re the mainstream. The radical fringe is people who put mass murderers on billboards to \'start a discussion.\'\" Fallout According to the Washington Post, the Heartland Institute pulled its billboards after U.S. GOP Representative and well-known climate denialist, James Sensenbrenner, told the group he would not speak at their upcoming climate summit if the billboard campaign continued. Sensenbrenner has now stated he will attend the summit, known as the Seventh International Conference on Climate Change. However, the fallout over the billboard campaign has lost Heartland Institute at least one speaker: Donna Laframboise, another climate skeptic and critic of environmental groups such as the World Wide Fund for Nature (WWF), has written that she will no longer attend the conference. \"Without prior knowledge or informed consent, my work has been aggressively associated with this odious ad campaign,\" she writes. \"Forget disappointment. In my view, my reputation has been harmed. And the Heartland thinks it has nothing to apologize for.\" Although the Heartland Institute has pulled the ad campaign it has since written, \"We do not apologize for running the ad, and we will continue to experiment with ways to communicate the \'realist\' message on the climate.\" The meeting\'s keynote speaker, the President of the Czech Republic, Vaclav Klaus, is still scheduled to appear. A well-known climate change denier, Klaus has called climate change \"a communist conspiracy.\" But Henn says the most recent scandal should make companies think again about financially supporting the conservative group. \"I don\'t think they teach you to support groups that call your customers \'serial killers\' in Marketing 101,\" he says. Recently General Motors (GM) announced it would no longer contribute to the Heartland Institute due to the group\'s stance on climate change, and following the billboard ad, past-donator Diageo, an alcoholic drink company, announced yesterday it \"has no plans to work with the Heartland Institute in the future.\" However a number of major companies, from Microsoft to Pfizer and Koch Industries to AT&T, continue to support the group. For its part Microsoft said in a statement that the Heartland Institute\'s \"position on climate change is diametrically opposed to Microsoft’s position. And we completely disagree with the group’s inflammatory and distasteful advertising campaign.\" However, the company said it has no plans of cutting off the Heartland Institute from its donation, which comes via a free software program for non-profits. The most recent scandal follows shortly after budget and donor documents were leaked from Heartland Institute by climatologist Peter Gleick, who gained access to the documents after pretending to be a board member via email. In an admission published in February, Gleick called his actions a \"serious lapse of my own and professional judgment and ethics.\" The documents showed that much of the Heartland Institute\'s climate action is funded by an \"anonymous donor\" and revealed plans to craft school curriculum to teach kids that anthropogenic climate change is \"a major scientific controversy,\" despite the fact that few scientists view it as such. The Earth has warmed 0.8 degrees Celsius (1.44 degrees Fahrenheit) since the early Twentieth Century. Impacts to date include melting glaciers, diminishing Arctic sea ice, and rising sea levels. Scientists also believe that climate change is likely increasing the frequency and intensity of droughts, floods, and heatwaves around the world.