Climate Change Threatens Health: Extreme Weather

Extreme Weather: Record-Breaking Events in 2011



2011 was a year of unparalleled extremes: 14 disastrous weather events in the US each resulted in over a billion dollars in property damage. This was an all-time record breaking number -- and their estimated $53 billion price tag did not include health costs. When health-related costs of extreme events are calculated, the total tally increases by billions more dollars, as shown recently, in a first-of-its-kind study published in the journal Health Affairs1. Costs will likely continue to climb as climate change continues.

Beach front home damaged by hurricane dennis


Since climate is the baseline for weather, alteration of the climate affects extreme weather events, too. Some people have likened the effects of climate change to "weather on steroids": taking steroids makes hitting a home run more likely for a ball player, and climate change makes some types of extreme weather events more likely.

A troubling trend has been identified by the international reinsurance company MunichRe2; they concluded that from 1980 through 2011, the frequency of damaging extreme events increased substantially in the U.S. Many of the 2011 extreme events, such as record temperatures, devastating storms, wildfires, and extreme droughts and floods, are among the types expected to worsen as climate change continues. A newly-released analysis by international climate scientists (the IPCC)3 concluded that climate change will amplify extreme heat, heavy precipitation, and the highest wind speeds of tropical storms.

We need to be prepared. Emergency planning must incorporate risks from climate change. For example, maps describing flooding zones need to account for increased risks caused by extreme rainfall and sea level rise resulting from climate change. While these plans are made at the local level, the Federal Emergency Management Agency (FEMA) must also prioritize addressing and preparing for climate change by providing guidance and resources to state and local governments.

See how states are addressing extreme weather events >>

  • California's plan addresses extreme heat, flood events, droughts, wildfires, water and food- borne illnesses and promotion of local food systems. The cities of Berkeley and San Francisco also address extreme weather events in their plans. Find out more >>
  • Florida's plan addresses extreme heat, storms, floods, wildfires, and increased risk of infectious diseases, particularly vector-borne diseases. Find out more >>
  • Maine's plan addresses extreme heat, storms, and risk of infectious disease due to extreme weather events. Find out more >>
  • Maryland's plan addresses extreme heat, storms, infectious diseases, food safety and supply. Find out more >>
  • Michigan's plan addresses extreme heat, storms, flooding, infectious diseases, food supply, public health infrastructure, and critical health services. Find out more >>
  • New York's plan addresses extreme heat, increased air pollution, risk of infectious diseases, and flood events. New York City's plan includes measures to decrease flooding risk by improving the stability of physical infrastructure. Find out more >>
  • Oregon's plan addresses extreme heat, flood events, droughts, storms, wildfires, food supply, agriculture, infrastructure design, food and water-borne pathogens, and mental health impacts. Find out more >>
  • Pennsylvania's plan addresses extreme heat, flooding, and drought events. Find out more >>
  • Virginia's plan addresses extreme heat, flood, drought, wildfires, infectious diseases, and storm events. Find out more >>
  • Washington's plan addresses extreme heat events. Find out more >>
  • Wisconsin's plan addresses extreme heat and flood events. The city of Milwaukee's climate plan includes goals to improve their warning system for extreme weather events. Find out more >>

Map Methods

This map was generated based on NRDC's Extreme Weather Map 2011 project which created an animated graphic that tracked "record-breaking" weather events over the course of 2011 within the 50 United States. The following modifications to the original methods were made to enable the geographic specificity of this map:

Monthly temperature, rain and snowfall records were compiled into a single map. Multiple monthly records at a single meteorological station are marked by a single icon.

Extreme drought point locations were replaced by a shaded polygon representing the geographic areas found to experience "Exceptional Drought" (D4) in 2011 by the National Drought Mitigation Center's Drought Monitor.

Extreme flood point locations to mark the Lower Mississippi Floods ( and Upper Midwest floods ( were replaced with shaded polygons created by digitizing maps produced by the National Climatic Data Center. Because flooded area maps were unavailable, the flood point locations marking record high peak flows due to the impacts of Hurricane Irene and Tropical Storm Lee were retained as point data.

The 10 large-scale storm events depicted as large polygons during the animated sequence were not included in this map.

Related Links

  1. Knowlton K, Rotkin-Ellman M, Geballe L, Max W, Solomon GM. 2011. Six climate change-related events in the United States accounted for about $14 billion in lost lives and health costs. Health Affairs 30(11):2167-2176.
  2. Munich Re. 2011.Half-Year Natural Catastrophe Review, July 12, 2011. MR NatCatSERVICE. Available at: A webinar regarding the entire year of 2011 by MunichRe is available at:
  3. IPCC Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation, Summary for Policymakers (Nov. 18, 2011), available at:
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