The scientific perspective is that global warming is real, it is causing harmful changes to the climate, and it is caused by human activity. A strong majority of Americans believe the planet is getting warmer, and most believe that humans are the cause. A disconnect occurs however when Americans are asked about risk. When asked will global warming harm us, that majority gets much more narrow. When asked will global warming harm you personally, all of a sudden the majority disappears.
We know it’s happening and it might impact others but we don’t believe it is a risk to us personally. Like so much else, the political divide over global warming is widening. As time goes on Democrats and to a lesser extent independents are becoming more convinced of global warming while Republicans less so.
Numbers are slowly increasing over time and across the political spectrum that global warming will have an impact in the future. Not surprisingly there is a strong inverse correlation between age and belief in the risk of global warming. Younger generations express much more concern than their elders. Women are more concerned than men, and the more educated express more concern than the less educated.
Denial of scientific evidence has been around since, well, science. Denial is strongest when the evidence challenges a particular worldview. Evolution of life on earth, especially the part about humans, is still denied by a significant minority of the public. A lot of folks learn their religion long before they learn science and among some religions, evolution is anathema.
John Scopes wasn’t prosecuted for teaching the atomic weight of Carbon. He was prosecuted for teaching that humans have an ancestor in common with apes’ ancestors. This has always been misunderstood as humans evolved from apes.
Galileo wasn’t convicted of heresy for showing that gravitational acceleration was constant (his famous dropping of dissimilar sized balls from a tower in his hometown of Piza.) No, his sin was to challenge the orthodoxy of the church about the sun circling the earth. Work with his invention, the telescope, led him to accept and promote the Copernican view of a heliocentric solar system. It took the church over 350 years to admit that he was right.
Reasons for denial of Anthropogenic Global Warming (AGW) range from simple ignorance to a purposeful deceit. Surely we puny humans can’t have an impact on the global climate (yes we can.) There is no way we could know what the temperature or atmosphere was like millions of years ago (yes we can.)
Slightly more sophisticated, but equally wrong, are some pseudoscientific arguments. One is that volcanoes emit much more Carbon Dioxide (CO2 ) than human activities, therefore it isn’t our fault. Nope, humans produce orders of magnitude more. A true, but immaterial statement is that water vapor in the air absorbs more heat than CO2 . The amount of water in the atmosphere is dependent on the temperature hence it is a result, not a cause of warming.
So why all the denial? H L Mencken put it nicely: “It is the nature of the human species to reject what is true but unpleasant and to embrace what is obviously false but comforting.”