I was, needless to say, astounded that someone who I usually engage in lively science-related conversation could hold such views -- views customarily associated with the likes of creationism or (shudder) libertarianism.
You see, in order to believe that humans are not responsible for climate change, you have to believe that one of the following facts is false:
- Carbon dioxide, methane, and other gasses trap infrared radiation in the atmosphere, a process called the greenhouse effect.
- Carbon dioxide, methane, and other greenhouse gasses have increased in the atmosphere by more than 35% in the last two hundred years.
- This rise and the introduction of widespread burning of fossil fuels being simultaneous is not a coincidence -- burning fossil fuels releases carbon dioxide, methane, and other greenhouse gasses.
- Throughout geological history, when greenhouse gas levels have risen at similar rates (due to various natural phenomena), temperatures have risen in response.
- Throughout geological history, when temperatures have risen in response to rising levels of greenhouse gasses, catastrophic climactic effects lasting centuries and millennia have resulted.
- Since we have produced a large amount of carbon dioxide, methane, and other greenhouse gasses in the last two hundred years, and similar levels of greenhouse gasses lead to rising temperatures, the rising temperatures we experience now are the result of our emission of greenhouse gasses; it is reasonable to predict that the trend will continue along historical lines.
- Since historical rises in temperature in response to greenhouse gasses have produced long-lasting, catastrophic climactic effects, it is reasonable to predict that the current rises in temperature will do so as well.
- Virtually every scientist in every country is part of a conspiracy to deceive people.
There is still hope for people, like the one I spoke to, who at least recognize the mechanisms that cause climate change, and accept some human responsibility. I think that it is not so much that he believes humans can't be responsible for such things as he doesn't want to believe we could be. Who wants to be complicit in ecocide?