 Carbon dioxide is the
leading heat-trapping greenhouse gas. Human activities
result in some 7 billion tons of carbon in the form
of carbon dioxide annually, with fossil fuel use the
largest single source. Since the Industrial Revolution,
carbon dioxide concentrations have increased by about
30 percent, primarily due to the burning of coal, oil,
and natural gas for industry, electricity-generation,
and transportation, and, to a lesser extent, the oxidation
of biomass and decomposition of soil organic matter
from conversion of forests to agriculture. Agriculture's
role in climate change is just starting to be recognized.
Clearing trees for fields and pastures, transforming
soil into cultivated land, flooding areas for rice and
sugarcane production, burning crop residues, raising
ruminant animals, and using nitrogen fertilizers all
release greenhouse gases into the atmosphere. Global
agriculture is now estimated to account for about 20
percent of total anthropogenic emissions of greenhouse
gases. Thus, agriculture plays a significant role in
climate change. Cost-effective reductions in greenhouse
gases can be achieved by:
- Better managing agricultural soils, rangelands,
and forests
- Improving the efficiency of fertilizer use
- Restoring degraded agricultural lands and rangelands
- Improving ruminants' digestion through better feed
- Improving rice farming to reduce the amount of methane
escaping into the atmosphere
- Slowing deforestation by reducing slash-and-burn
agriculture
- and establishing appropriate tree plantations.
Forest and agricultural soils are potential repositories
of carbon and could hold down concentrations of carbon
dioxide in the atmosphere. Their potential for trapping
additional carbon each year is high if farmers adopt
improved management practices, including agroforestry.
According to IPCC estimates, the potential for carbon
sequestration in tropical ecosystems by the year 2010
is 125 megatons of carbon a year for croplands, 170
megatons for forests, and 240 mega-tons for grazing
lands
For the world's poorest farmers the global response
to climate change could be an enormous opportunity to
grow higher-yielding crops, healthier animals, and more
sustainable forests, and improve their livelihoods;
for all of us, the correct response could protect the
environment for future generations
Source CGIAR |
