claim: There is ample evidence that Earth's average temperature has increased in the past 100 years and the decline of mid- and high-latitude glaciers is a major piece of evidence.
evidence: There is considerable evidence that over the very recent period of the last 100–1000 years, the sharp increases in human activity, especially the burning of fossil fuels, has caused the parallel sharp and accelerating increase in atmospheric greenhouse gases which trap the sun's heat.