A key feature of climate change is that it doesn’t pose one single risk. Rather, it presents multiple, interacting risks that can compound and cascade. Importantly, responses to climate change can also affect risk.
In our highly connected world, climate risks and our responses to them can be transmitted from one system or sector to another, creating new risks and making existing ones more or less severe. In many cases risks cannot be understood without considering these interactions.
Recent evidence indicates how some of the most severe climate change impacts, such as those from deadly heat or sudden ecosystem collapse, are strongly influenced by interactions across sectors and regions.
For example, global warming of 2°C is projected to reduce yields of staple crops by 5%–20%. The compound interaction between heat and drought can make the risk to crops more severe. In response, global trade networks that link distant food systems together can help compensate for reduced local food security. But they can also create new risks, such as more rapid spread of disease, pests and invasive species. And new threats to local food security can arise from commodity price spikes caused by policy responses to climate shocks elsewhere.
Limiting global warming will reduce risk to crop yields. Yet the response actions selected to achieve this will also affect risk. For example, planting forests might displace food crops. Read more…