Al Gore conducted an open online Q&A on reddit.com today. Here’s a gem from it. [Note: if you’re not familiar with reddit, be prepared for a lot of snarkiness.]
For people that may be skeptical about global warming, what is the one undeniable scientific fact that you feel backs it up the most effectively?
Al Gore’s reply
There are at least 15 deeply researched separate lines of evidence that all confirm man-made global warming. They are all consistent, each with the others. Every National Academy of Science on the planet agrees with the consensus. The Academies describe the evidence as “indisputable”. Every professional scientific society in every field related to climate science and earth science also agree. And 97-98% of climate scientists worldwide most actively publishing also agree. Animals and plants also agree — in that they are moving their ranges by latitude and altitude to find climate niches similar to the ones in which they evolved.
Even if you leave climate science completely out of it and just measure extreme temperatures, the statistical record of global temperatures shows that three-standard deviation events have increased from 0.25% of the time (from 1951-1980) to 10% of the time now.