New report highlights “significant and increasing” risks from extreme weather

Professor Peter Cox, from Exeter’s Mathematics department said: “We are much more vulnerable to climate change than is normally assumed. For example, it is normal to think about global warming in terms of the global mean temperature increase, which is dominated by the large ocean area that warms much more slowly than the land. Unfortunately people live on the land, so they experience much more than the global average warming.

“This report has highlighted the need to make people and infrastructure much more resilient to climate change. The recommendations include more consideration of ecosystem-based approaches to protection, such as maintaining coastal wetlands or forests, and more explicit consideration of climate risks in company finances.”

Professor Katrina Brown from the Environment and Sustainability Institute at the University of Exeter’s Penryn Campus in Cornwall added: “Building resilience to climate change and extreme weather must start now. We need to anticipate and plan for events, rather than wait until after them. Our analysis shows that a combination of conventional engineering and ecosystem-based approaches, which harness and enhance the buffering capacity of natural landscapes, are likely to be most effective. Governments should work alongside communities and other groups to find the best ways to keep people safe now and in the future.”

Between 1980 and 2004 the total cost of extreme-weather related events came to $1.4 trillion. Populations in countries with a low Human Development Index make up only 11 percent of those exposed to hazards but account for 53 percent of disaster mortality.

The report compares various practical options for the most effective and affordable defense against the impacts of flooding, drought and heatwaves.

The report concludes that engineered options, such as dams, sea walls, and wells are often the most effective at reducing the impact of a particular hazard, but that they are also expensive, and if they fail they fail cataclysmically. If used in combination with ecosystem-based approaches such as floodplain or mangrove re-establishment and planting vegetation they can be more effective and affordable as well as delivering wider benefits on an on-going basis — not just when the hazard strikes. These ecosystem or “natural” approaches are often more affordable and can have multiple additional benefits to society.

The working group therefore recommends that ecosystem-based approaches are increasingly used in combination with more traditional approaches, although more effort is needed to ensure they are systematically monitored and evaluated. The report uses the Slowing the Flow initiative in Pickering, U.K. as an example of where this is being done.

Professor Georgina Mace, chair of the working group for the report, said: “We are not resilient to the extremes of weather that we experience now and many people are already extremely vulnerable. If we continue on our current trajectory the problem is likely to get much worse as our climate and population change. By acting now, we can reduce the serious risks to our children and grandchildren.

“National governments have a responsibility to do everything in their ability to protect their people from the devastation caused by extreme weather events.”

Speaking from the report launch event in Bangalore, India, Professor Paul Bates from the University of Bristol’s Cabot Institute, said: “For the first time this report makes clear that global society is not resilient to the extreme weather that we experience now, and that in the future, with population and climate change, we will be even more threatened.” 

Professor Bates, a member of the report working group, emphasizes the need for action: “Importantly the report makes a number of practical suggestions, such as encouraging businesses to report exposure to natural hazards in their annual accounts, that will start to address this situation.”

The report also calls for changes to global financial accounting and regulation to ensure that extreme weather risk is made explicit. At present, these risks are not systematically factored into investors’ valuations or assessed by creditors.

Business surveys, economic forecasts, and country briefings that guide investment decisions and credit ratings are typically based on the availability of skilled labor, access to export markets, political and economic stability, and financial incentives — but there is little or no consideration of actual or potential exposure to disaster risks.

Specifically, the Royal Society suggests that companies report the following:

  • 1 in 100 (1 percent) risk per year — a stress test for a company’s solvency that evaluates the maximum probable losses expected for events that occur, on average, once in a hundred years or have a 10 percent chance of occurring every decade
  • 1 in 20 (5 percent) risk per year — a stress test for a company’s annual earnings
  • Annual Average Loss — a standardized metric for a company’s exposure to extreme events

The full report and interactive versions of global maps showing the change in exposure to floods, droughts, and heatwaves between 2010 and 2090 is available on the Web site.

— Read more in Resilience to extreme weather (The Royal Society, 2014)