I often raise the issue of "What is Normal" when discussing climate. The media frequently declares certain weather events as so "abnormal" that they must be due to man-made factors. A great example is the current Texas drought, which is somehow unprecedented and thus caused by CO2 despite the fact that the great dust bowl drought of the 1930's was many times larger in area and years in duration.
The EPA has a new slideshow purporting to aggregate these "abnormalities." While I could spend all year going through each slide, I want to focus on just one.
Now we all know that the EPA is just full of sciency goodness and so everything they say is based on science and not, say, some political agenda. And the statement and the pictures above are absolutely correct, as far as they go. But they are missing a teeny tiny bit of context. Here is a longer history of that same glacier (thanks to the Real Science blog for the pointer, this is a much better map than the one I have used in the past).
The 1948 position is way up at the top. You can see that the melting since 1966, which according to the EPA is an "acceleration," is trivial compared to the melting since 1760. Basically, this glacier has been retreating since at least the end of the little ice age.
Those who want to attribute the recent retreat to CO2 have to explain what drove the glacier to retreat all that way from 1760 to 1960, and why that factor stopped in 1960 at exactly the time Co2 supposedly took over.
By the way, this same exact story can be seen in glaciers around the world. Glaciers began retreating at the end of the little ice age, and if anything that pace of retreat has slowed somewhat over the last few decades.