By Josh Fischman

It's getting warmer, leading to dangerous heat waves, and it's getting wetter, producing more floods. Climate change is definitely increasing the risk of those hazards in many parts of the world, reported the world's leading climate-change study group on Friday. The group—the United Nations Intergovernmental Panel on Climate Change, or IPCC—used cautious language about the source of that change, saying there was evidence it was due to human activities but it was unclear how much we are to blame.

The focus of the report is less on causes and more on effects, and what particular geographic areas can do to reduce risk. The 29-page document, "Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation," concludes that "it is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes" will occur during this century, so it "is very likely that the length, frequency, and/or intensity of ... heat waves will increase." Also "it is likely the frequency of heavy precipitation ... will increase," particularly in high latitudes and in the tropics.

Those findings mean different things for different regions. The report gives a few examples:

  • Europe will bear the brunt of more heat waves, and a lack of air conditioning and an aging population are the major risks. Solutions include public air-conditioned spaces and more-aggressive social-care networks.
  • Hurricanes in the Caribbean and the United States are likely to increase in maximum wind speeds and the rain they drop (though a rise in the number of such storms is not strongly supported by scientific evidence). Population growth and sea-level rise will heighten the risk in this area. To manage those dangers, the report suggests better building codes and, naturally, better weather forecasting.
  • In East Africa there are likely to be more heavy rains leading to flash floods. Settlements built near rivers or blocked drainage areas will raise the risks here. Stronger buildings, improved drainage systems, and a reduction in poverty would help.
  • In West Africa, by contrast, the 220 scientists and policy makers who wrote the report had little confidence in drought projections for the region. Nonetheless, they recommend more use of drought-resistant crops and improved water management.

Christopher Field, a professor of environmental earth science at Stanford University who was a lead author of the report, said in a statement that he hoped it "can be a scientific foundation for sound decisions on infrastructure, urban development, public health, and insurance, as well as for planning."