More than CO2: a broader paradigm for managing climate change and variability to avoid ecosystem collapse

Climate change policies currently focus on reducing the concentration of industrial atmospheric greenhouse gases due to burning fossil fuels and deforestation, but pay limited attention to feedbacks between the land surface and the climate system. In tropical and subtropical regions, forests and woodlands play an important role in the climate system by buffering climate extremes, maintaining the hydrological cycle and sequestering carbon. Despite the obvious significance of these feedbacks to the functioning of the climate system, deforestation continues apace. It is critical, therefore, that a broader focus be developed that includes the restoration of feedbacks between vegetation and climate. In this paper, we present a synthesis of the best available, policy-relevant science on the feedbacks between the land surface and the climate system, with a focus on tropical and subtropical regions. On the basis of this science, we argue for a stronger integration of land-use and climate-change policies. These policies need to include a virtual halt to all deforestation and an acceleration of investment in strategic reforestation, supported by a comprehensive global forest monitoring program. Without these actions, the degradation of the Earth's ecosystems will become exacerbated as their resilience is eroded by accelerated changes in temperature, precipitation and extreme weather events.