I recommend checking out the before and after photos of the world's many well known glaciers. There are indeed some very dramatic changes. CO2 emissions are destabilizing our atmosphere and ecosystem. Being a closed system afterall, I think there's only so much that the nature can handle. Global warming shouldn't have to come slap one in the face to make him believe in it. It's not the temperatures that we experience today that concern us, it's about what our children and grandchildren will have to face, if we don't do something about it today.
This one's from the USGS: