What happens next?

"The climate is an angry beast, and we are poking at it with sticks."
Wallace Broecker

Dr Broecker, of Columbia University, New York, USA, was the first scientist to describe the worldwide ocean 'conveyor-belt' currents which partly control climate. These currents ship a lot of heat from the tropics to regions like northern Europe via the Gulf Stream. Without this warmth, northern Europe would be much colder.

What happens next is not good news for people or penguins. The thing that bothers me is that the ice of the poles is melting. Some of it already is melting fast. The Arctic sea ice gets less every year and the great frozen continent of Antarctica (my home) is losing ice too. Other seas, like the North Sea, are warming too. This means that fish which need colder waters have to swim north and this can have bad effects on both fishing and seabirds.

Penguins in distress
Adelie Penguin numbers in the Antarctic have shrunk by one third during the past 25 years. This is because there is less winter sea ice where they live.

Warming is 5 times greater than average. Since 1945, the Antarctic Peninsula has warmed about 2.5 degrees C (4.5 degrees F ). Each year's melting season has gone up by 2 to 3 weeks in just the past 20 years.

Where is the North Sea?
This sea lies between Great Britain on the west side, and Scandinavia on the east. It's best known these days for declining oilfields and fish stocks.

As you know, penguins like ice. Without very cold water and ice, we get too hot because, like polar bears, we're built for cold weather. But for you people, it will be much worse.

Poor bears
Polar bears depend for their food on seals. They can only hunt the seals when there is floating sea ice because the seals have breathing holes in the ice where the bears ambush them. The seals also have their pups on the ice. No ice, no seals, no polar bears.

For a start, all the ice that melts will start to fill up the oceans and make them overflow on land. And the water itself will take up more space simply because it is warmer. That will make it overflow even more onto the land.

This is called thermal expansion — warmer water takes up more space.