[Texgreen] Global warming; faster and worse than previously expected

[Roger Baker]

<http://observer.guardian.co.uk/uk_news/story/0,,1995348,00.html>

Global warming: the final verdict

A study by the world's leading experts says global warming will =20
happen faster and be more devastating than previously thought Robin =20
McKie, science editor Sunday January 21, 2007 The Observer

Global warming is destined to have a far more destructive and earlier =20=

impact than previously estimated, the most authoritative report yet =20
produced on climate change will warn next week.

A draft copy of the Fourth Assessment Report of the Intergovernmental =20=

Panel on Climate Change, obtained by The Observer, shows the =20
frequency of devastating storms - like the ones that battered Britain =20=

last week - will increase dramatically.

Sea levels will rise over the century by around half a metre; snow =20
will disappear from all but the highest mountains; deserts will =20
spread; oceans become acidic, leading to the destruction of coral =20
reefs and atolls; and deadly heatwaves will become more prevalent.

The impact will be catastrophic, forcing hundreds of millions of =20
people to flee their devastated homelands, particularly in tropical, =20
low-lying areas, while creating waves of immigrants whose movements =20
will strain the economies of even the most affluent countries.

'The really chilling thing about the IPCC report is that it is the =20
work of several thousand climate experts who have widely differing =20
views about how greenhouse gases will have their effect. Some think =20
they will have a major impact, others a lesser role. Each paragraph =20
of this report was therefore argued over and scrutinised intensely. =20
Only points that were considered indisputable survived this process. =20
This is a very conservative document - that's what makes it so =20
scary,' said one senior UK climate expert.

Climate concerns are likely to dominate international politics next =20
month. President Bush is to make the issue a part of his state of the =20=

union address on Wednesday while the IPCC report's final version is =20
set for release on 2 February in a set of global news conferences.

Although the final wording of the report is still being worked on, =20
the draft indicates that scientists now have their clearest idea so =20
far about future climate changes, as well as about recent events. It =20
points out that:

=B7 12 of the past 13 years were the warmest since records began;

=B7 ocean temperatures have risen at least three kilometres beneath the =20=

surface;

=B7 glaciers, snow cover and permafrost have decreased in both =20
hemispheres;

=B7 sea levels are rising at the rate of almost 2mm a year;

=B7 cold days, nights and frost have become rarer while hot days, hot =20=

nights and heatwaves have become more frequent.

And the cause is clear, say the authors: 'It is very likely that [man-=20=

made] greenhouse gas increases caused most of the average temperature =20=

increases since the mid-20th century,' says the report.

To date, these changes have caused global temperatures to rise by =20
0.6C. The most likely outcome of continuing rises in greenhouses =20
gases will be to make the planet a further 3C hotter by 2100, =20
although the report acknowledges that rises of 4.5C to 5C could be =20
experienced. Ice-cap melting, rises in sea levels, flooding, cyclones =20=

and storms will be an inevitable consequence.

Past assessments by the IPCC have suggested such scenarios are =20
'likely' to occur this century. Its latest report, based on =20
sophisticated computer models and more detailed observations of snow =20
cover loss, sea level rises and the spread of deserts, is far more =20
robust and confident. Now the panel writes of changes as 'extremely =20
likely' and 'almost certain'.

And in a specific rebuff to sceptics who still argue natural =20
variation in the Sun's output is the real cause of climate change, =20
the panel says mankind's industrial emissions have had five times =20
more effect on the climate than any fluctuations in solar radiation. =20
We are the masters of our own destruction, in short.

There is some comfort, however. The panel believes the Gulf Stream =20
will go on bathing Britain with its warm waters for the next 100 =20
years. Some researchers have said it could be disrupted by cold =20
waters pouring off Greenland's melting ice sheets, plunging western =20
Europe into a mini Ice Age, as depicted in the disaster film The Day =20
After Tomorrow.

The report reflects climate scientists' growing fears that Earth is =20
nearing the stage when carbon dioxide rises will bring irreversible =20
change to the planet. 'We are seeing vast sections of Antarctic ice =20
disappearing at an alarming rate,' said climate expert Chris Rapley, =20
in a phone call to The Observer from the Antarctic Peninsula last =20
week. 'That means we can expect to see sea levels rise at about a =20
metre a century from now on - and that will have devastating =20
consequences.'

However, there is still hope, said Peter Cox of Exeter University. =20
'We are like alcoholics who have got as far as admitting there is a =20
problem.

It is a start. Now we have got to start drying out - which means =20
reducing our carbon output.'=