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Rising temperatures

The consequence of increasing CO2 and other pollutant levels will be higher average global temperatures, meaning unpredictable weather, rising sea levels, and perhaps runaway heating as the whole climate system slips out of gear.

Scientists predict that if we go on as we are, by 2100 global sea levels will probably have risen by 9 to 88cm and average temperatures will be between 1.5 and 5.5C higher than now.

That may not sound very much - but the last Ice Age was only 4-5C colder than today.

The sceptics are unmoved. Some say the human influence on the climate is negligible, and that isolating one small variable, CO2 and other greenhouse gas levels, in an immensely complex natural system is meaningless.

Others insist such measurements are flawed andИthe predictions unreliable. Yet others believe a warmer world would be better for most of us.

They are entirely right to argue that thereДare still many uncertainties about the climate and any influence we may have on it.

ing to reduce its extent but byбadaptingАto its effects.

Sobering facts

But many who were once sceptics now accept that enhanced climate change is happening, and that we have to respond - not necessarily by try-

Part of the problem isиthat climate change is now part of the stuff of science fiction, with Hollywood and some campaign groups alike feeding scare stories thatСowe little, if anything, to scientific fact.

But the facts are sobering enough. We know that average global surface temperatures have risen by 0.6C in the last 140 years.

All of the 10 warmest years have occurred since 1990, including each year since

1997. The possibilities are sobering too.

Many water-scarce regions now will probably become thirstier.

Some countries may be able to produce bigger harvests, but in others yields will drop. Sea level rise may make many coastal areas uninhabitable.

Weather patterns may change, producing more heat waves, droughts, floods and violent storms.

Aid agencies are warning that these combined effects could seriously jeopardise attempts to lift the world's poorest people out of poverty.

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Furthermore, there is also the possibility of "positive feedbacks"- for example, higher temperatures may release more methane from the Arctic tundra and CO2 from peat bogs, which will themselves speed up the warming process.

Then there is the inertia of the atmosphere and the oceans.

What we do today may literally determineАДhow long the Greenland icecap survives - even though, at fastest,бit will still take a good few centuries to disappear.

Delayed effect

If somehow we could halt all greenhouse gas emissions tomorrow, the

heating would continue for decades or centuries.

Creating worldwide consensusиon this global problem is difficult, not least because of the economic cost of cutting down on greenhouse gas emissions.

And wildlife, less equipped to adapt than humans, could be hit hard. One estimate suggests hundreds of thousands of species may be at risk of extinction by 2050Сbecause of climate change.

The Kyoto Protocol, which commits rich countries to reducing emissions, is a small but necessary start on building an international system for tackling climate change, its proponents believe.

But the country responsible for about a quarter of the world's greenhouse gas emissions, the US, has refused to sign up to it.

The protocol does not require developing countries to cut their emissions, although fast-industrialising countries like China will soon be significant contributors as those in poor nations increasingly demand rich world lifestyles.

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For them, emissions cuts could have significant social costs in slowing the growth that feeds economic development, creates jobs and helps lift the poor out of poverty.

A prudent look at the evidence, preliminary though it is, suggests we shall be wise to err on the side of caution.

Dr Geoff Jenkins, of the UK Met Office's Hadley Centre for Climate Prediction and Research, said recently: "Over the last few decades there's been much more evidence for the human influence on climate.

"We've reached the point where it's only by including human activity that we can explain what's happening."

And what's happening now could lead to a world beyond our experience

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Self-Assessment

Module 8

1. Look through Module 8 to find the answers to the questions 1 – 20.

1. List the ecological problems.

2. What causes all environmental problems?

3. How do population growth influence environment?

4. What is human pressure?

5. Why is poverty a factor of environmental problems?

6. What pollutes the environment?

7. What is “greenhouse effect”?

8. What is “dead zone”? Give the examples.

9. What happened to Bhopal?

10. How much water does an average human body contain? 11. What are the ways to clear up the planet?

12. What do humans need to survive?

13. Is it a myth or a fact that if you boil your tap water for ten minutes, you

18. List as many facts as youбcanАabout the ocean using The Bounty of the Sea by Jacques Cousteau.

19.Why does Sir David King think that climate change is a far greater global threat thanСinternational terrorism?

20.What is the Kyoto Protocol?и

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2. There are at least 28 hidden words. Find them!

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