Good news: Norway has become the first country to ban deforestation. The Norwegian Parliament pledged May 26 that the government’s public procurement policy will be deforestation-free. Any product that contributes to deforestation will not be used in the Scandinavian country. The pledge was recommended by Norwegian Parliament’s Standing Committee on Energy and Environment as part of the Action Plan on Nature Diversity.
Nonlocal effects: Deforestation influences surface temperature at the location of deforestation (local effects) and elsewhere (nonlocal effects). […] Using simulations in a climate model, we show that deforestation-induced changes in the brightness of the surface influence surface temperature mainly nonlocally and thus may be largely overlooked in observation-based data sets. The simulations show that the nonlocal effects have a larger impact on global average surface temperature than the local effects, independent of how much area is deforested and at which latitude the deforestation takes place.
Stable forests: We argue that resource and finance allocation for stable forests should be incorporated into countries’ and donors’ comprehensive portfolios aimed at tackling deforestation and forest degradation as well as resulting emissions.
Key policy insights:
Vicious cycle of destruction in the Amazon:
Here we show that the risk of self-amplified Amazon forest loss increases nonlinearly with dry-season intensification. […] Our results suggest that the risk of self-amplified forest loss is reduced with increasing heterogeneity in the response of forest patches to reduced rainfall. […] Although our findings do not indicate that the projected rainfall changes for the end of the twenty-first century will lead to complete Amazon dieback, they suggest that frequent extreme drought events have the potential to destabilize large parts of the Amazon forest.
Deforestation and the global water cycle:
We show that deforestation is as large a driving force as irrigation in terms of changes in the hydrological cycle. Deforestation has decreased global vapor flows from land by 4% (3,000 km3/yr), a decrease that is quantitatively as large as the increased vapor flow caused by irrigation (2,600 km3/yr). Although the net change in global vapor flows is close to zero, the spatial distributions of deforestation and irrigation are different, leading to major regional transformations of vapor-flow patterns. We analyze these changes in the light of future landuse-change projections that suggest widespread deforestation in sub-Saharan Africa and intensification of agricultural production in the Asian monsoon region. Furthermore, significant modification of vapor flows in the lands around the Indian Ocean basin will increase the risk for changes in the behavior of the Asian monsoon system.
Major land use and land cover changes in Brazil and their impacts on precipitation and evapotranspiration:
For the Amazon biome, decreasing dry season P and in annual ET were reported. In the Cerrado biome, decreasing P in the wet and dry seasons and decreasing dry season ET were the most common result. For the Atlantic Forest biome, increasing annual P and increasing wet season ET, likely due to reforestation, were reported.