One of the aspects that worries me the most about the climate changes we are seeing is the loss of ice and snow pack in the Mountains. There is a report out from the US Geological Service done in partnership with the the Universities of Arizona, Washington, Wyoming, and Western Ontario that points to some of the problems coming down the river.
USGS Study Finds Recent Snowpack Declines in the Rocky Mountains Unusual Compared to Past Few Centuries
"Runoff from winter snowpack – layers of snow that accumulate at high altitude – accounts for 60 to 80 percent of the annual water supply for more than 70 million people living in the western United States.
“This scientific work is critical to understanding how climate change is affecting western water supplies,” Secretary of the Interior Ken Salazar said. "
"This study supports research by others estimating that between 30-60 percent of the declines in the late 20th century are likely due to greenhouse gas emissions."
And the thing is it isn't just the water supply for these people. This is the water that is part of the irrigation for much of the food eaten in North America. We are seeing the major cities getting concerned about how they are going to take water away from the food producers that feed them. Similar problems are happening in and around the Alps and the Himalayas. Food is going to become harder to get/more expensive. Hydro-electricity isn't going to be able to rely on the melt in all of those regions like it does now. This is going to be a problem.