Although carbon dioxide from fossil fuel combustion is the primary cause of global warming, other human activities and greenhouse gases are also central to the climate story. Today, forests and soils contain three times as much carbon as is currently in the atmosphere. These lands also provide critical natural services to humanity and shelter much of the world’s biodiversity. But in many countries, remaining forests are being decimated by industrial logging and conversion to agriculture.
To solve this piece of the climate problem, humanity will need to greatly reduce the destruction of forests and improve management of cropland and livestock. The good news is that emissions reductions through land use and forestry changes are generally inexpensive, conserve soils, and boost farm income.
The clearcutting of rain forests is concentrated in about 10 nations, and accounts for about 10 percent of greenhouse gas emissions. Developing equitable arrangements for forest protection is an essential part of any climate action plan. Since forest conservation is one of the largest and most affordable greenhouse gas reduction opportunities, it is a logical centerpiece of emerging international carbon offset and trading plans.
Atmospheric concentrations of two other greenhouse gases – methane and nitrous oxide – have also grown rapidly. Methane is a very powerful greenhouse gas, accounting for about 18 percent of the current warming. Forty percent of methane emissions come from livestock, rice paddies, and other agricultural activities.
Nitrous oxide accounts for about 9 percent of greenhouse gas warming. Its primary sources are agricultural soils and fertiliser use, animal manure, and power plant and vehicle exhausts. There is a growing range of approaches for reducing these emissions, often at a profit.
From a global perspective, farmers, ranchers, and forest dwellers are the logical providers of emissions “offsets” that can be traded between countries. Policy opportunities include:
- Developing programs that offer indigenous peoples incentives to preserve local forests.
- Rewarding farmers and ranchers for altering their agricultural practices, with the aim of reducing soil and livestock emissions.