First study of all Amazon greenhouse gases suggests the

damaged forest is now worsening climate change

    The Amazon rainforest is most likely now a net contributor to warming of the planet, according to a first-of-its-kind analysis from more than 30 scientists.

    For years, researchers have expressed concern that rising temperatures, drought, and deforestation are reducing the capacity of the world’s largest rainforest to absorb carbon dioxide from the atmosphere, and help offset emissions from fossil-fuel burning. Recent studies have even suggested that some portions of the tropical landscape already may release more carbon than they store.

    But the inhaling and exhaling of CO2 is just one way this damp jungle, the most species-rich on Earth, influences the global climate. Activities in the Amazon, both natural and human-caused, can shift the rainforest’s contribution in significant ways, warming the air directly or releasing other greenhouse gases that do.

    Yet no team had ever tried to assess the cumulative impact of these processes, even as the region is being rapidly transformed. The research estimates that atmospheric warming from all of these sources combined now appears to swamp the forest’s natural cooling effect.

    The damage, however, can still be reversed. Halting global emissions from coal, oil, and natural gas would help restore balance, but curbing Amazon deforestation is a must, along with reducing dam building and increasing efforts to replant trees. Continuing to clear land at current rates appears certain to make warming worse for the entire world.

Internet:<www.nationalgeographic.com> (adapted). 

How rich countries cause deforestation in poor ones

    Forests are crucial to the functioning of the Earth. They provide homes for plants and animals, absorb rainfall, produce oxygen and suck up carbon dioxide, helping to keep global temperatures in check. Environmentalists are increasingly worried about their loss. Ten thousand years ago, more than half of the world’s habitable land was covered in trees; since then one third have been cut down to make way for agriculture and an ever-growing number of humans. Efforts to reverse this trend, including tree-planting programmes in America, Europe, China and India, among other places, have helped replenish some of what is left of the world’s forests.

    But such gains do not tell the whole story. For all their tree-planting efforts at home, rich countries continue to contribute, through their consumption, to the levelling of vast tracts of forests in poor countries. A study, published on March 29th in Nature Ecology & Evolution, reveals the extent and location of the world’s “deforestation footprint”. Keiichiro Kanemoto and Nguyen Tien Hoang, of the Research Institute for Humanity and Nature in Japan, combined data on global forest loss with that on international trade between 2001 and 2015. They calculated that rich-country demand for goods led overwhelmingly to deforestation outside their own borders, and mostly in tropical countries. In G7 countries, for example, the area covered by forests increased every year between 2001 and 2015. But after adjusting for trade, the authors found that these countries contributed to a net loss of 20,000 square kilometers of forest in the rest of the world in 2015 alone.

Internet: <www.economist.com> (adapted).