Land-use protection for climate change mitigation

• Published in: Nature climate change 2014-12, Vol.4 (12), p.1095-1098
• Main Authors: Popp, Alexander, Humpenöder, Florian, Weindl, Isabelle, Bodirsky, Benjamin Leon, Bonsch, Markus, Lotze-Campen, Hermann, Müller, Christoph, Biewald, Anne, Rolinski, Susanne, Stevanovic, Miodrag, Dietrich, Jan Philipp
• Format: Article
• Language: English
• Subjects: 704/106/694/682; 704/172; Agricultural expansion; Agricultural land; Agricultural production; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Carbon dioxide; Climate Change; Climate change mitigation; Climate Change/Climate Change Impacts; Climatology. Bioclimatology. Climate change; Deforestation; Earth, ocean, space; Emissions; Environment; Environmental Law/Policy/Ecojustice; Exact sciences and technology; External geophysics; Forest conservation; Fundamental and applied biological sciences. Psychology; Global warming; Land use; letter; Meteorology; Regrowth; Synecology; Terrestrial ecosystems; Tropical forests; Vegetation regrowth
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/nclimate2444

A significant challenge for policies aiming to reduce carbon emissions from deforestation is the avoidance of international carbon leakage. Research now shows, however, that even globally implemented forest conservation schemes could allow another type of carbon leakage through cropland expansion into non-forested areas. Land-use change, mainly the conversion of tropical forests to agricultural land, is a massive source of carbon emissions and contributes substantially to global warming 1 , 2 , 3 . Therefore, mechanisms that aim to reduce carbon emissions from deforestation are widely discussed. A central challenge is the avoidance of international carbon leakage if forest conservation is not implemented globally 4 . Here, we show that forest conservation schemes, even if implemented globally, could lead to another type of carbon leakage by driving cropland expansion in non-forested areas that are not subject to forest conservation schemes (non-forest leakage). These areas have a smaller, but still considerable potential to store carbon 5 , 6 . We show that a global forest policy could reduce carbon emissions by 77 Gt CO 2 , but would still allow for decreases in carbon stocks of non-forest land by 96 Gt CO 2 until 2100 due to non-forest leakage effects. Furthermore, abandonment of agricultural land and associated carbon uptake through vegetation regrowth is hampered. Effective mitigation measures thus require financing structures and conservation investments that cover the full range of carbon-rich ecosystems. However, our analysis indicates that greater agricultural productivity increases would be needed to compensate for such restrictions on agricultural expansion.