Picture a square of tropical rainforest 100m to a side. According to a study from 2000, it is heavily laden with carbon: between 155 and 187 tonnes for wet forest and between 27 and 63 tonnes for dry. That means that each square kilometre of rainforest is holding between 2,700 and 18,700 tonnes of carbon: with about 70% of that in trees, 20% in the soil, and the rest in roots, understory, and litter.
Cutting down the trees for timber and to open farmland releases some portion of that stock into the atmosphere: with the amount dependent on how the soil’s carbon absorption changes and what is done with the wood and wood waste. When the forest is burned, either intentionally to clear land or unintentionally, the bulk of that carbon gets released into the atmosphere more of less immediately. As a result of both land use change and forest burning, the World Resource Institute estimates that deforestation represents about 18.3% of all human greenhouse gas emissions. As such, tackling it is a priority.
Arguably, the best thing individuals can do is refuse to eat meat or use first-generation biofuels. A considerable amount of cattle production takes placed in cleared areas of rainforest, with additional land cleared to grow soya to feed to cattle. On the biofuels front, there are both situations where rainforest is cleared directly for biofuel plantations (palm oil) and situations where the use of agricultural land to grow biofuel crops (corn) increases the overall need for agricultural land, pushing things like soy production into previously forested areas.
One other element to be aware of is the connection between population growth, urbanization, and deforestation. Several states actively encourage people to relocate from crowded areas to more sparsely populated zones bordering forested areas. Indonesia has sought to shift people away from Java in the same way Brazil has encouraged development in the Amazon to try to reduce crowding in the south.
Addressing deforestation is thus a two-fold proposition. In the first instance, the developed world needs to be aware of how commercial activities directly encourage deforestation. Restricting the use of tropical hardwoods, encouraging vegetarianism and veganism, and improving public transit would all help. Secondly, developing states must be encouraged to value their forests at a level high enough to prevent their destruction. That will probably require some kind of international financial instrument whereby the states actually protecting forests receive payments from all the states that benefit from ecological services those forests provide. The latter is a more wide-ranging solution, but the former can be more immediately implemented. If we are to keep that carbon in rich tropical soil and majestic tree trunks, action on both fronts needs to be undertaken.
- Papdopol, C.S. “Impacts of climate warming on forests in Ontario: options for adaptation and mitigation.” Forestry Chronicle. 76(1): 139-149 (2000).
- Livingston, Nigel and G. Cornelis van Kooten. “Terrestrial Carbon Sinks and Climate Change Mitigation.” in Coward, Harold and Andrew Weaver eds. Hard Choices: Climate Change in Canada.