State of the Rainforest 2014

World biomes and carbon storage

Carbon stored by biome* Billion of tonnes (Gigatonnes)

Tropical, Subtropical Forests

600

Boreal Forest

500

Temperate Forest

Temperate Grasslands, Savannas Shrublands

400

Deserts and Dry Shrubland

300

Tropical, Subtropical, Savannas, Shrublands

Tundra

200

100

* Carbon storage values include above- and below-ground storage and soil storage. Values calculated by UNEP-WCMC, 2009

0

Source: Adapted from Olson, D., M., Terrestrial Ecoregions of the World: a new map of life on Earth. Bioscience, 2001; WCMC 2009

instance, are no longer reliable, and although this is not systematic and scientifically produced knowledge, it corresponds to the changes being observed by researchers. The 2014 report from the IPCC states that both in South America and in Central Africa one can conclude with “medium certainty” that changes in rainfall, floods and droughts are related to climate change. 52 The geographical distribution of species is changing because of climate change. 53 There is an emerging debate about whether climate change has already led to the extinction of species, and about what level of climate change that may trigger large scale extinction. 54 The IPCC has previously assessed that as much as 30% of the world’s biodiversity could be threatened in a “medium scenario”, with temperature rise by more than 3 degrees centigrade. 55 The huge, densely forested areas of the Amazon, the Congo Basin – and to some extent Southeast Asia – have a direct impact on the planet’s systems for exchanging oxygen and humidity, producing rainfall and cloud formations. There is a lot of uncertainty regarding how climate change will affect this, but the consequences may be far-reaching. Both in the Amazon and in the Congo Basin the forests themselves generate a large part of total rainfall. If the forests are reduced to such an extent that their capacity to create their own rainfall is hampered, a tipping point will be reached that may have irreversible consequences. This mechanism is best understood in the Amazon, where the Andean mountain range prevents humidity from escaping west into the Pacific, driving rainfall north and south of the Equator. Reduced rainfall and cloud formation are bound to affect agricultural production within these regions, and the effect may reach other continents.

Improved remote sensing and monitoring technology nevertheless means that figures for forest cover, carbon content and the emissions stemming from forest destruction gradually become more reliable. In the 2007 IPCC report, emissions from deforestation were estimated to be 17%. The fact that the current estimate has been reduced to 11% does not primarily reflect reductions in deforestation, however. Greenhouse gas emissions from other sources have increased significantly, and methods for calculating emissions have developed. 50 Even if deforestation currently contributes relatively less to overall carbon emissions, it is still vital to reduce forest-related emissions to reach the international goals of limiting climate change to below two degrees centigrade. Halting the destruction of tropical forests is more important than the 11% share would seem to indicate. In addition to their role in regulating climate patterns and rainfall and absorbing and storing carbon, emissions from tropical deforestation may be reduced rapidly, as the Brazilian example demonstrates. Given the urgency of rapidly reducing emissions, and the time it will take to alter the global energy matrix from fossil to renewable sources – reducing emissions from deforestation is vital. Climate change threatens the rainforest Rainforests are vulnerable to climate change. Higher temperatures and less rainfall over a period of time can lead to drought in areas that usually have moist rainforest, as we have seen happen in the Amazon and Asia during recent years. 51 Rainforest inhabitants describe that the climate is changing. Traditional signs indicating when to plant, for

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STATE OF THE RAINFOREST 2014