Planting Trees May Not Help Stop Global Warming
10/23/99
OVERVIEW & COMMENTARY
We know relatively little about what holds the global ecological
system together. Recent climate change research indicates that
planting trees may be a bad way to address global warming. It may
well be a case of the axiom that "complex problems have simple, easy
to understand, wrong answers." Essentially, the new theory states
that forests planted as a sink for carbon become saturated and return
their carbon to the atmosphere, perhaps accelerating climate changes
at that time. This argues even more strongly for reducing carbon at
its source through reductions in emissions rather than seeking some
magic bullet to save us from the urgency of doing so. "Sinks are
much less secure than carbon and fossil fuels left unburnt, as things
may change unpredictably over time." These findings relate more to
the alleged carbon sequestering benefits of planting trees, and does
_not_ mean carbon currently tied up in natural forests should be
released through continued deforestation--with other land use changes
currently the second largest source of increased atmospheric carbon
dioxide.
g.b.
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Title: Trees lose their appeal as panacea for global warming
Source: Independent (London)
Status: Copyright 1999, contact source for permission to reprint
Date: October 21, 1999
Byline: Oliver Tickell
Planting trees may be a bad way of trying to slow global warming,
according to research from the United Nations Intergovernmental Panel
on Climate Change.
It says new "carbon sink" forests will quickly become saturated with
carbon and begin to return much of the carbon they contain into the
atmosphere just as global warming accelerates.
The panel's report, highlighted in New Scientist magazine, undermines
a key provision of the Kyoto Protocol, which requires industrialised
countries to cut CO2 emissions. Under it, countries are allowed to
offset emissions by planting trees, at home or in other countries,
and count the carbon so absorbed against their industrial emissions.
The United States in particular has taken this route rather than
seeking more efficient energy and generation use or developing
renewable sources. Confronted with the panel's findings, the US
Environmental Protection Agency has refused to comment on the issue.
But the problem of "sink saturation" will catch up with the agency at
the intergovernmental meeting in Bonn next week, where it will be a
big theme. Some countries, including the US, had hoped to use the
meeting to complete plans for "carbon forests". But with the
credibility of the idea demolished by climate scientists, it looks
improbable that any agreement will be reached.
Britain in particular thinks carbon sink forests should take low
priority. "The main action should be reducing emissions," said a
Department of the Environment spokesman. "Sinks are much less secure
than carbon and fossil fuels left unburnt, as things may change
unpredictably over time."
In its last assessment in 1996 the panel concluded that "carbon
fertilisation", by which elevated CO2 levels stimulate plant growth,
would cause forests to soak up 290 million tonnes of carbon over the
next century, even without new planting. With planting, that could be
raised by another 100 million tonnes. The figures promised a
substantial "carbon sink" into which industrial CO2 emissions, now 6
million tonnes a year, could vanish.