Here’s a novel idea. Since president of the United States is not only the most important job in this country, but also the most powerful on the planet, doesn’t it make sense to require an IQ test before anybody can run for that office? Of course, it does. And Marco Rubio should be the first.

The junior senator from Florida, an all-but-declared candidate for president in 2016, made headlines this week when he joined the ranks of climate deniers. Sort of. While Rubio accepts that global warming is happening, he denies that human activity has anything to do with it. It’s just nature doing its thing, he says.

Asked on ABC’s “This Week” if climate change were a big threat, Rubio expressed his skepticism: “Our climate is always changing. And what they have chosen to do is take a handful of decades of research and say that this is now evidence of a longer-term trend that’s directly and almost solely attributable to man-made activities.” In other words, says Rubio, since man has nothing to do with climate change, we need do nothing about it. He, in fact, opposes any climate-change legislation.

Welcome to the dumbing down of the Republican Party. In 2008, remember, both Barack Obama and John McCain agreed on the reality of global warming and the urgency of taking action. There was no difference between them on the issue. Heck, even George W. Bush believed that today’s dramatic and already disastrous effects of climate change are due to human activity. But not Rubio.

Rubio’s professed ignorance is all the more stunning given the flood of new warnings on climate change we’ve seen recently. On March 30, a U.N. report by Nobel scientists warned that if nations don’t soon cut pollution by heat-trapping gases, the already-disastrous effects of global warming could “spiral out of control.” The Intergovernmental Panel on Climate Change cited killer heat waves in Europe, wildfires in the United States, droughts in Australia and deadly flooding in Mozambique, Thailand and Pakistan as evidence of global warming already taking place around the planet. The dangers are going to worsen as the climate changes even more, scientists warned.

On May 6, the White House released an equally scary report on the status of global warming here in the United States. Again, nobody escapes. More than 300 experts contributed to the National Climate Assessment report. Their take-away message: Climate change is here; it’s already impacting every corner of the country and every sector of the economy; and again, absent bold, new action, it’s only going to get worse. Their money quote: “Climate change, once considered an issue for a distant future, has moved firmly into the present.”

But wait, there’s more. On May 13, the Center for Naval Analyses issued its own assessment of climate change from the perspective of national security. The title of its report, prepared by a panel of 11 retired generals and admirals, says it all: “National Security and the Accelerating Risks of Climate Change.” At the same time, NASA reported that last month was the second-warmest April since scientists began recording temperature data – and just happened to be the 350th month in a row where the planet has experienced above-average temperatures. In a separate study, NASA also warned that melting of the West Antarctic ice sheet is “un-stoppable” and could raise sea levels by 4 feet – which means the United States would lose 28,000 square miles of land, including 85 percent of Florida’s Broward and Miami-Dade counties. Miami officials, in fact, have already declared an emergency and approved spending $400 million to deal with rising sea levels.

And there, in the face of all that overwhelming evidence, stands the dim-witted junior senator from Florida. Don’t tell him his own state may soon sink beneath the waves. He doesn’t “believe” it. Yet, when pressed this week at a National Press Club event, Rubio could not name one single source, study, or scientist to support his denial of human-caused climate change. He doesn’t need any evidence. He just doesn’t “believe it.” What a pathetic excuse for inaction, especially by someone planning to run for president.

See what I mean? From now on, we should forget about demanding that candidates for president show their birth certificate. They should be required to take an IQ test, instead, which would be bad news for Marco Rubio. He’d flunk it.

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