Today, just one country releases almost one quarter of global greenhouse gas emissions. Every year its population is responsible for more than 19 tons of greenhouse gases per head - that's more than four times the global average. But this country refuses to sign up to the Kyoto Protocol - the international agreement designed to reduce carbon emissions and curb climate change.

This country is the United States.

Without the cooperation of the US in a joint global effort to reduce greenhouse gas emissions, the efforts of other nations are effectively negated. But the US is not immune to the damaging effects of climate change. Many of the US states are seeing dramatic changes in their environments and ecosystems - the effects of which are already impacting on its gas-guzzling population.

Alaska: war in slow motion?

With an area of over 1.5 million square kilometers, Alaska is bigger than the next three of the largest US states combined. It has 3 million lakes more than 8 hectares, 5,000 glaciers and 17 of the highest 20 mountains in the US. But the vastness and remoteness of this land does not protect it from the effects of climate change.

In the last ten years Alaska has lost more trees than in the previous 60 years combined. 1.2 million acres of spruce pine forest, the most dominant of the three tree species that flourish in this northern region, are diseased and dying and in some areas more than 90% are dead.

Ecologists studying the cause of this widespread destruction have pointed the finger at the bark beetle - a beetle normally associated with killing spruce pine trees in warmer southerly latitudes. Climatologists are linking the invasion of bark beetle with a steady rise in winter temperatures. And if temperatures continue to rise, Alaska could see a dramatic change in it's ecology - from pine forests to brush and grasses.

While an increase in temperature might benefit many varieties of insects and pests, it does not help preserve the world's ice sheets. Next, Earth Report travels to the north mid-western state of Montana which has seen a striking decrease in the number and size of its glaciers.

Montana: net losses

Outside of Alaska, Montana contains one of the largest areas of undisturbed wilderness in the United States and some of the most southerly glaciers to be found on the continent. Around half the world's glaciers have already been lost and Montana's Glacier National Park has not escaped these losses.

Over the last 150 years the number of glaciers in the park has decreased from 150 to less than 37 - retreating most significantly as mean summer temperatures began to climb this century.

With its sparse population, scientists have been able rule out local and regional human causes behind this glacial retreat - and rule in an overall change in climate. At the present rate, all Montana's glaciers will disappear by the year 2030. And if this is indicative of a global loss in ice cover across the world, sea levels will undoubtedly continue to rise and weather patterns change.

Eastern Seaboard: on collision course

The impact of global warming on the world's oceans is already having a significant effect on the temperate and tropical coastal areas of the United States. As sea levels rise, barrier islands have started to disappear and once protected mainland is being eroded.

While coastal erosion is a relatively slow and unstoppable force, the damage from flood and storm is far more immediate. And it's getting worse.

If temperatures continue to rise, the Eastern Seaboard could see isotherms shifting northwards in the ocean. This means that while the number of hurricanes will not increase, they will intensify. As hurricanes move in over warmer water their wind speeds stay very high. The United States may soon have to deal with the very real possibility that savage storms like 1992's Hurricane Andrew - which devastated Florida and Louisiana with 250km an hour winds and left 30 billion dollars worth of damage in its wake - will become a regular occurrence.

This combination of erosion and extreme weather conditions puts about 3.1 trillion US dollars worth of real estate on the Eastern Seaboard at risk.


Taking action

Climate respects no boundaries and the effects of global warming are already evident. But it's not too late. There are very real economic alternatives to fossil fuels. And by using energy more efficiently, wasting less and travelling less, the prognosis is good. But the US has to implement measures that will reduce CO2 into our atmosphere - and it must act now.