Around 300 million hectares go up in flames every year. The result: a cloud of CO2 and sterile soils.
ENVIRONMENT travels to Marseille in the South of France where over 13OO hectares of land were brunt to a crisp in July. Over the past few years wildfires have become increasingly common and more widespread.
"We're seeing more and more extreme conditions of drought and heat waves, conditions that with a changing climate will happen more frequently, conditions that are ideal for fires, particularly intense ones," notes Corrine Lampin of Cemagef, a public agricultural and environmental research institute.
Global warming and mankind are causes common across continents but the flames are fanned differently depending on the type of tree. Mediterranean forests are suffering because of the rural exodus that leaves lands barren and dry and quick to ignite.
Tropical forests have the opposite problem and are under pressure from constant fires by farmers and industries clearing land for new plots to harvest. Finally boreal forests are less sensible to human activity but more susceptible to climate change.
Wildfires are not only destroying communities, they also pose an increasing threat to the environment. As forests burn, the carbon they contain is emitted into the atmosphere.
A 2008 study by the American National Center for Atmospheric Research showed that such fires could also raise levels of ozone at ground level.
When fires hit the same spot again and again, the soil becomes so fragile that it's eventually unable to regenerate.
"The quantity of organic matter and the quality of the soil are equally important, and everything that's a part of biological activity - bacteria in the soil or ground animals - are affected by fires; if they recur too often, these communities lose their capacity for resistance, their resiliance. We think you need about fifty years between two fires for an ecosystem to completely recover to a quantifiable level,” explains Michel Vennetier of Cemagef.
The real time bombs however are peat-bogs. Plant matter builds up in them over centuries and when they burn, it releases CO2 that’s been trapped for centuries.
Finally ENVIRONMENT travels to Kenya to visit the Mau Forest. Once a 400,000 hectare thicket of trees spread across the rolling hills of the southern Rift Valley it has contracted by 30% since the early 90s. According to the United Nations the land is being destroyed by tens of thousands of settlers who have cleared the cedar trees to make way for farming land. The result is reduced rain capture and a drought that threatens the lives of 10 million people.
Date created : 2009-07-31