In a taste of what may be to come, the worst drought in a century struck Brazil in 2005, reducing rivers to record low flows, and causing water shortages, devastating forest fires and power shortages as Brazil’s hydroelectric sector, struggled to cope with low water and high demand.
The future also promises new diseases in new places, as rising temperatures expand the habitats of tropical insects carrying the likes of malaria and dengue fever into the typically cooler southern parts of the country. In early 2007, more than 85,000 cases of dengue fever were reported in southwestern Brazil, a 30 per cent rise on the previous year.
And climate change threatens widespread hunger and dislocation on a continent where 30 to 40 per cent of people are still farmers. Studies in Brazil, Chile, Argentina, and Uruguay show declining yields in key crops – barley, grapes, maize, potatoes, soybeans, and wheat – potentially linked to global warming.
The continent’s forests will play a critical role in mitigating the regional and global impacts of climate change, and yet they themselves are at risk. These forests account for more than one-quarter of global forests, and are essential to the carbon cycle that regulates the planet’s oxygen and carbon dioxide.
If temperatures rise more than the critical 2ºC threshold and continued drying leads to large-scale die-back, a vicious circle may be created whereby the carbon released from the decomposing vegetation will accelerate global warming and lead to the extinction of countless plant and animal species.
Scientists are now trying to determine the temperature at which the Latin American forests will cease to cope and ecosystems begin to collapse. Some researchers say that threshold could be passed in the next few years. Others say it is decades away, provided the forests are not destroyed.
Researchers have found that more than 18,000 square kilometers of rainforest was destroyed in 2004-05 to make way for cattle pastures, soybean farms, or other land use that is more economically profitable than untouched rainforest. Deforestation affects regional rainfall and climate patterns, while slashing and burning releases massive amounts of carbon dioxide and represents up to 75 percent of Brazil’s total greenhouse gas emissions.
Retaining forests is one of the most effective ways to mitigate the rate and severity of regional as well as global climate change. The international community has an important role to play in helping Latin American countries to reduce and eventually halt deforestation, particularly by supporting community-based strategies.
For example, donor countries and organisations should dramatically increase support for small-scale agriculture. Highly diverse systems, as opposed to commercial monocultures, have repeatedly been shown to be more resilient, more productive, less likely to involve wholesale forest clearance and less reliant on expensive and energy-intensive inputs such as fossil fuels and artificial fertiliser.
Boosting crop yields is crucial to relieving the pressure to clear new land. This requires systems that combine new insights and technologies with the wisdom of tradition. That means more research. Clearing forest land and planting biofuels as opposed to food crops should also be avoided.
Latin American countries can assist the fight against climate change by adopting clear targets and timetables for reducing deforestation by improving local governance and providing incentives for sustainable forest management. Such initiatives could benefit from donor country support.
Tropical deforestation has negative impacts on biodiversity, air quality, local communities, and indigenous peoples. Reducing deforestation is also the key to reducing overall greenhouse gas emissions and staying below the 2C global warming threshold. The international community must support Latin American countries in this effort with appropriate technology, resources and regulations, for all our sakes. CM