Climate Change, A Risk Assessment Report

A climate change risk assessment must consider at least three areas: the future pathway of global emissions; the direct risks arising from the climate’s response to those emissions; and the risks arising from the interaction of climate change with complex human systems. Each of these areas contains large uncertainties. From our assessment, we draw the following conclusions about the most significant risks.

• Emissions: Without increased political commitment and an acceleration of technological innovation, global emissions are likely to follow a medium to high pathway: continuing to increase for the next few decades, and then levelling off or decreasing gradually. 
• Direct risks: The risks of climate change are non-linear: while average conditions may change gradually, the risks can increase rapidly. On a high emissions pathway, the probability of crossing thresholds beyond which the inconvenient may become intolerable will increase over time. 
• Systemic risks: The risks of climate change are systemic. The greatest risks may arise from the interaction of the climate with complex human systems such as global food markets, governance arrangements within states, and international security.