IPCC Releases Full Report on Extreme Weather Risk Management

Back in November the Intergovernmental Panel on Climate Change (IPCC) released the executive summary for a “special report” called Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX for shorthand). Today, the IPCC released the full technical report that underlies the executive summary. In addition to documenting the scientific evidence that extreme weather events are on the rise, the report provides a risk-based analysis of how society can best respond to the climate threat. In the words of Chris Field, co-chair of one of the two working groups that produced the report:

“The main message from the report is that we know enough to make good decisions about managing the risks of climate-related disasters. Sometimes we take advantage of this knowledge, but many times we do not.  The challenge for the future has one dimension focused on improving the knowledge base and one on empowering good decisions, even for those situations where there is lots of uncertainty.”

The main conclusions about weather trends include:

  • “It is likely [> 2:3 odds] that anthropogenic influences have led to warming of extreme daily minimum and maximum temperatures at the global scale.”
  • “There is medium confidence that anthropogenic influences have contributed to intensification of extreme precipitation at the global scale.”
  • “There is medium confidence that some regions of the world have experienced more intense and longer droughts.”
  • “It is likely that there has been an anthropogenic influence on increasing extreme coastal high water due to increase in mean sea level.”
  • There is low confidence in any observed long-term (i.e., 40 years or more) increases in tropical cyclone activity (i.e., intensity, frequency, duration), after accounting for past changes in observing capabilities.
  • There is low confidence in observed trends in small spatial-scale phenomena such as tornadoes and hail because of … inadequacies in monitoring systems.

The report finds compelling evidence that manmade greenhouse gases have contributed to some of these trends. At the same time, damages and costs from extreme weather events have been increasing in recent decades. That trend is due in large part to socioeconomic trends – like more people and wealth concentrating along coastlines where storms sweep them away. But from a risk-management perspective, it is common sense to realize that when two trends are both moving in the direction of greater risk, it’s time to do something about it.

The SREX appropriately dedicates much more text on social risk factors, such as trends in settlement patterns, sub-population vulnerability, and uneven capacity to adapt to changing weather patterns. It finishes with what we know and don’t know about how society can/should respond to changing weather extremes, focusing on “low-regret” strategies that have improved health and safety already and that simply make the world a better place to live, such as early warning systems, insurance innovations, and infrastructure improvements.

I suspect most people will find the SREX report highly technical; even the summary for policymakers might be slow reading for many. Fortunately, there is a handy 3-page fact sheet that boils it down neatly. Also, C2ES released a paper last December called Extreme Weather and Climate Change: Understanding the Link, Managing the Risk. That paper is in accord with the SREX and offers an accessible overview of extreme weather risk for the interested public. Of course, anyone who wants the gory details is welcome do dive into the full technical SREX document.

Keep your eyes open for our brief summary of the full report coming next week.

Jay Gulledge is Senior Scientist and Director of Science & Impacts Program at C2ES.