'Halt CO2 by 2050 to save Earth'
2009-01-14 08:14
Washington - To avoid the most
catastrophic effects of climate change, world carbon emissions
will have to drop to near zero by 2050 and "go negative" after
that, the Worldwatch Institute reported on Tuesday.
This is a deeper cut than called for by most climate
experts and policymakers, including President-elect Barack
Obama, who favours an 80% drop in US carbon emissions
by mid-century.
Limiting carbon emissions aims to keep global mean
temperature from rising more than 2°C
over what it was before the Industrial Revolution - but one
Worldwatch author said even this is too dangerous.
"Global warming needs to be reduced from peak levels to 1°C as fast as
possible," co-author William Hare said at a briefing on the
"State of the World 2009" report. "At this level you can see
some of the risks fade into the background."
Climate-warming carbon dioxide
Global mean temperature has already risen 0.8°C) since 1850, so drastic cuts in emissions of
climate-warming carbon dioxide are needed, according to Hare,
now working at the Potsdam Institute for Climate Impact
Research in Germany.
Hare said that global greenhouse gas emissions would need
to hit their peak by 2020 and drop 85% below 1990 levels
by 2050, and keep dropping after that.
He said carbon dioxide
emissions would have to "go negative", with more being absorbed
than emitted, in the second half of this century.
The burden of cutting greenhouse emissions should fall more
heavily on rich countries than poor ones, Hare said, with
industrialised nations reducing emissions by 90% by
2050, allowing developing nations to let their economies grow
and develop new technologies that will ultimately reduce
climate-warming gases.
2009: a pivotal year?
Even with these dramatic changes, the world may face an
additional rise of nearly 1°C because
the impact of past greenhouse emissions hasn't yet been felt on
surface temperatures, the report said.
This year could be pivotal in the movement against climate
change, said co-author Robert Engelman, with "scientists more
certain and concerned, the public more engaged than ever
before, an incoming US president bringing to the White House
for the first time a solid commitment to cap and then shrink
this country's massive injections of greenhouse gases ... into
the atmosphere".
Engelman also noted this year's deadline for a global
agreement to craft a successor pact to the carbon-capping Kyoto
Protocol. This is set to happen in December at a meeting in
Copenhagen.
Engelman said the Copenhagen meeting could put in place a
new "financial architecture" that discourages greenhouse
emissions and rewards actions that take these emissions out of
the atmosphere.
Cap-and-trade system
This could take the form of a cap-and-trade system or a
carbon tax, he said, and could also include "the best terms of
trade, investment and credit" for countries that make the
transition to a low-carbon economy.
"However this turns out, we still have some precious time
and a clear shot at safely managing human-induced climate
change," Engelman said.
"What's at stake is not just nature as
we've always known it, but quite possibly the survival of our
civilisation. It's going to be a really interesting year."
Commenting on the report, environmental chemist Stephen
Lincoln of the University of Adelaide in Australia said in a
statement: "The strongest message from State of the World 2009
is this: if the world does not take action early and in
adequate measure, the impacts of climate change could prove
extremely harmful and overwhelm our capacity to adapt."
The Washington-based Worldwatch Institute is an independent
research organisation.