Grim findings on global warming
Martin Khor
With the world in economic recession, there is a temptation to
downgrade or sideline climate change. That would be a great mistake.
The
gathering of 2,000 scientists in Copenhagen in March found
the climate change situation much worse than previously
reported. They called on politicians to act quickly and
decisively. |
However serious the recession, the effects of climate change will be
even more devastating and long lasting.
In Copenhagen in March, 2,500 scientists met in a three-day meeting
and issued a grim warning that the climate situation is far worse than
what had been depicted in 2007 by the United Nations’ inter-governmental
panel on climate change (IPCC).
Environment
They said that global warming is increasing beyond the worst
forecasts, threatening to trigger irreversible shifts on the Earth’s
environment, and resulting in social conflict and war in much of the
world.
In a statement addressed to politicians, scientists warned: “The
worst-case IPCC scenario trajectories (or even worse) are being realised.
There is a significant risk that many of the trends will accelerate,
leading to an increasing risk of abrupt or irreversible climatic
shifts.” One example is that the IPCC predicted the sea level would rise
by 7ins-23ins by the end of the century. But recent research showed that
the rise could be 20ins-39ins.
Glaciers
The rising sea level is caused by the melting of glaciers and ice
sheets, and the effect is to flood coastal areas, causing millions of
people to move from their homes and lands.
Warning that “dangerous climate change” is imminent, the statement
said there is “no excuse for inaction” and that weak and ineffective
governments must stand up to big business and vested interests.
|
Global warming is increasing beyond
the worst forecasts |
The British economist Lord Nicholas Stern, who in 2006 wrote a famous
book on the economics of climate change, said his report had
under-estimated the risks of global warming.
“The reason is that emissions are growing faster than we thought, the
absorption capacity of the planet is less than we thought, the
probability of high temperatures is likely higher than we thought, and
some of the effects are coming faster than we thought,” he said.
The effects will be devastating unless politicians grasped the
gravity of the situation, added Stern. The most talked about scenario is
for the average global temperature to rise by 2°C-4°C by the end of this
century (compared with pre-industrial levels).
But Stern warned that a 6°C rise is an increasing possibility. That
could mean massive rises in sea levels, whole areas devastated by
hurricanes and others turned into desert, forcing billions of people to
leave their homes.
Much of southern Europe would look like the Sahara, many of the
world’s major rivers would dry up in the dry season or re-route, Stern
added.
Hundreds of millions or probably billions would have to move, and the
implications of that are “extended conflict, social disruption, war
essentially, over much of the world for many decades”.
Rainforest
The conference heard that much of the Amazon rainforest may already
be doomed. A study by the Hadley Centre of Britain showed that even a
rise of just 2°C (above pre-industrial levels) could cause 20%-40% of
the forest to die in the next hundred years.
But this horror story is from the best scenario, that global
emissions will peak in 2015 and then decrease significantly from then,
while in fact emissions are presently still rising. A temperature rise
of 3°C would see drought destroy 75% of the forest, and a 4°C rise would
kill 85%, according to a Guardian report of the paper. The loss of the
Amazon would in turn have a catastrophic effect on climate.
Another study showed that global warming may be converting tropical
forests from net carbon sinks (that absorb carbon) to net carbon
emitters.
Rising levels of CO2 in the atmosphere increase the growth of trees
but also cause trees to die younger, and this reduces the carbon storage
capacity of the rainforests.
Temperature
According to a Guardian report, Australian scientist David Hilbert
estimated that each degree of temperature rise will result in 14 tonnes
of carbon emissions per hectare of rainforest, equating to 24.5
gigatonnes of carbon worldwide, or two-and-a-half times the world carbon
emissions in 2007.
At a warming rate of 0.05°C per year, forests will produce 1.2
gigatonnes a year of carbon, more than they are currently absorbing as a
sink (about 1 gigatonne a year).
The Copenhagen meeting also heard other scientific findings showing
why the climate situation is worse than that depicted by the IPCC’s 2007
reports.
The Guardian columnist George Monbiot reported:
Partly because the IPCC estimates took no account of meltwater from
Greenland’s glaciers, the rise in sea levels this century could be two
or three times as great as it forecast, with grave implications for
coastal cities, farmland and freshwater reserves.
Bacteria
A warming of 2°C in the Arctic could trigger a massive bacterial
response in the soils there. As the permafrost melts, bacteria are able
to start breaking down organic material that was previously locked up in
ice, producing billions of tonnes of carbon dioxide and methane. This
could catalyse one of the world’s most powerful positive feedback loops,
with warming causing more warming.
Perhaps the most bitter-sweet report from Copenhagen was the “good
news” that the current world recession could cause greenhouse gas
emissions to drop by 40%-50%, according to an estimate by Terry Barker,
director of the Centre for Climate Change Mitigation Research at
Cambridge University.
Third World Network Features
The writer is the Executive Director of South Center |