On the other hand some alarms are on the silly side. Take, for instance, from yesterday's paper, this:
You Don't Want to Live to be 500

The Earth's atmosphere has already passed the tipping point, and in the next 500 years, temperatures will rise considerably, sea levels will rise considerably and millions, even billions, of people from the tropical and temperate zones of the Earth will be forced to migrate north in search of food, fuel and shelter. This is where Alaska, and Alaskans, will play a central role.

"By the year 2500, Alaska could be home to millions of climate refugees from the Lower 48 and Central and South America who will have migrated north, seeking safe harbor from the devastating impact of global warming in those future times"

It is not that I necessarily disbelieve Dan E. Bloom's premise but worrying about what could happen 500 years from now seems prematurely alarmist. He says that this generation and the "next few generations" won't need to worry but after that, watch out..