A few weeks ago, I posted a blog on the Heartland Institute and an awful ad campaign it had been running. Rather than trying to use facts in its efforts to sway people against a belief that climate change and global warming are real and result mostly from our human activities, it stooped to the low level of trying to equate anyone who might believe in climate change to mass murderers and terrorists like Ted Kaczynski aka the Unabomber, Charles Manson, Osama bin Laden, and Fidel Castro. With the huge public outcry and a major loss of supporters that ensued as part of the fallout from the first ad that was posted, the Heartland Institute pulled down the billboard after 24 hours, and didn’t bother to put up any of the others it had planned.

This week, the Heartland Institute has convened its seventh annual international conference on climate change. Dubbed ICCC-7, it’s taking place May 21-23, 2012 in Chicago, not far from where their billboard was posted, no doubt in efforts to promote the event. (As they say, bad publicity is better than no publicity at all.) At least two speakers withdrew from the conference: Donna Laframboise, an opponent of fracking technology, and economist Ross McKitrick. Even Congressman Jim Sensenbrenner, a Republican from Wisconsin who is no friend to the environment—check out his positions on energy and oil and his lack of support for the environment—threatened to remove himself from the conference unless the ad campaign was withdrawn. Despite the campaign being considered a colossal failure by almost everyone, the Heartland Institute has yet to apologize or claim any regret for funding the Unabomber ad.

The Climate Reality Project has decided to use the opportunity to fight back. Founded and chaired by former Vice President Al Gore, The Climate Reality Project has more than 5 million members and supporters worldwide. It is guided by what it claims is one simple truth: “The climate crisis is real and we know how to solve it.” They use funds to help spread Mr. Gore’s message, training speakers to provide lectures similar in format to the one depicted in the Oscar-winning documentary “An Inconvenient Truth.”

This week the Climate Reality Project is going to run their own ad in the same spot as the controversial Unabomber ad. Capitalizing on what I consider a much better ad campaign strategy—passing along facts rather than idiotic rhetoric equating believers in climate change to horrible people—they simply point out that you might want to believe scientists on this scientific issue.

Frequently the point is made that the vast majority of the world’s climate scientists agree that global warming and climate change are real, and that we are the main cause of it at present. I myself have frequently used such statements. It’s worth pointing out where such a claim comes from. The largest source of support comes from the Intergovernmental Panel on Climate Change. Established in 1988, its reports comprise the work of thousands of scientists from more than 120 countries, with their reports based mostly on peer-reviewed scientific publications. Their last report published in 2007 states that there is a greater than 90 percent chance that human activities are the cause of global warming. As the leading international network of climate scientists, that’s a group worth listening to on the issue in my opinion.

However, many other groups have reviewed data and expressed their own opinions about the issue. National science academies from the following countries have explicitly expressed support for the concept that global warming and climate change are real, and that our human activities have been the largest contributor over the last half-century:

Australia, Belgium, Brazil, Cameroon, Canada, the Caribbean, China, France, Germany, Ghana, India, Indonesia, Ireland, Italy, Japan, Kenya, Madagascar, Malaysia, Mexico, New Zealand, Nigeria, Russia, Senegal, South Africa, Sudan, Sweden, Tanzania, Turkey, Uganda, the United Kingdom, the United States, Zambia and Zimbabawe

That’s a lot of support from the scientific community, and worthy I believe of using the phrase “vast majority of climate scientists” when describing that support. To date, no national academy of science anywhere in the world has published a statement to the contrary.

So my answer to the Climate Reality Project’s billboard question is pretty obvious. I’m always going to believe the consensus opinion of scientists when it comes to scientific issues. They’re the best experts we have.