http://192.168.2.6/english/全球性暖化.rm

For millions of years, the changes in earth climate have been driven by forces of nature, before the last century and half, earth average temperature has been rising faster than any time in the past ten thousand years, the consensus in science is that much of that change has been driven by us.

We’re on the track to 700 past per million of carbon dioxide on the planet, we haven't seen that for 50 million years.

The signs are everywhere, droughts in the American Southwest and Africa’s Sahara, rising seas in Louisiana and Bangladesh, tropical diseases spreading north and extremes of weather from Florida to France.

The climate is not what it used to be, it’s not your grandfather’s climate any more.

You know there are people who still say global warming needn’t concern us, if it’s happening at all, it’s a natural trend not much we can do about it, but there is now hard evidence which shows that the warming is not real, it’s accelerating, it’s altering the climate’s most basic elements like rainfall and evaporation, days of sunshine and nighttime temperatures, those changes are damaging the environment in agriculture production, threatening wild species with extinction and putting at risk our life styles, our health, some of our favorite cities by the sea. In the next hour we follow the signs and see who if anyone is responsible. We will meet scientists who are investigating new climate evidence and will see what we can do to help.

It all starts with the warming, but up here in the eastern Arctic, reports of heat waves and droughts seem far away, and our guide Band Covick is more concerned with the melting, the disappearance of the sea ice in snow pack on a scale that is hard to grasp. Over the last 100 years, the world has seen a one degree Fahrenheit rise in its average temperature, but here end in Alaska, the average has climbed 4 to 7 degrees Fahrenheit in just 50 years.

The ices is forming a lot later than usual over the past few years and it's breaking up a lot earlier, so that means the less ice there is, the less hunting that can be done by our people and that means less country food, it means there’s been a great shift in terms of the seasons and the changing of the environment in the Arctic here.

Earth polar regions are signaling us that something unusual is happening, in the Antarctic, in January 2002 the Larsen B ice shelf broke up into small pieces. An area about the sizes of Rhode Island melted in less than a month.