* Deforestation, which is occurring all over the world, has a doubly damaging effect: it
reduces the number of trees that can recover the carbon dioxide produced by human activities,
and it releases into the atmosphere the carbon contained in the trees that are cut down.
* The world at large currently doesn't "pay" much for the positive
effects of forests. The value of trees as lumber and as firewood, and the value of
the land they occupy for housing or farming, tend to be short-term and specific. In fact,
these benefits may be a matter of survival in some regions. The value of forests for
preventing global warming and preserving the earth's biodiversity, by contrast, are
long-term and their rewards apply to everyone generally. A way has to be found to make the
expansion and nurturing of forests appealing and cost-effective to the local populations that
usually decide their fate.
* In terms of efforts to reduce global warming, a forest in one place is as good as a forest
in another. That can give rise to certain practical arrangements and efficiencies. Under the
Kyoto Protocol, once it takes effect, industrialized countries which lack
space or cost-effective options for expanding forests on their own territories may partially
compensate for their greenhouse-gas emissions by paying for the establishment and maintenance
of forests in other countries.
Changing agricultural methods
* Carbon stored in agricultural soils often can be preserved or enhanced by switching to
"no-tillage" or "low-tillage" techniques, which slow the rate at which
organic soil matter decomposes.
* In rice fields, emissions of methane, a powerful greenhouse gas, can be suppressed to some
extent through tillage practices, water management, and crop rotation.
* Using nitrogen fertilizers more efficiently can reduce emissions of nitrous oxide, another
potent greenhouse gas.