National Aeronautics and Space Administration

National Climate Assessment

NASA National Climate Assessment (NCA) Activities

NASA Centers Call for Proposals

National Climate Assessment - 2011 NASA Centers Call For Proposals

Lead PI and Center: Dale Quattrochi, Marshall Space Flight Center
Title:  Development of National Future Heat Scenarios to Enable the Assessment of Climate Impacts on Public Health
Proposal Type: Assessment Capabilities & Products
Co-investigators: William L. Crosson, Ph.D., Universities Space Research Association, National Space Science and Technology Center, Huntsville, AL; Mohammad Al-Hamdan, Ph.D., Universities Space Research Association, National Space Science and Technology Center, Huntsville, AL; Maurice G. Estes, Jr., M.S., University of Alabama in Huntsville; Sue Estes, M.S., University of Alabama in Huntsville


FINAL PROJECT SUMMARY

This sequence shows the averave annual number of days on which the Heat Index exceeded, or is expected to exceed, 100 degrees Farenheit. The increase in such hot days across the US is dramatic and is expected to have serious public health impacts, as heat is the #1 weather-related cause of deaths in the US.
This sequence shows the mean annual maximum Heat Indes for the recent past to the end of the 21st Century. Increases in the Heat Index across the US are dramatic due to predicted higher temperatures and humidities. This is expected to have serious public health impacts, as heat is the #1 weather-related cause of deaths in the US.

In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization which contributes to local-scale urban heat islands, it is very likely that extreme heat events will become more common and more severe in the U.S. The objective of this project is to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S. (CONUS). We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The project’s emphasis is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change captured via GCM output, and the temporal and spatial characteristics of short-term extremes are represented for the CONUS.

Two future time horizons, 2031-2060, and 2081-2110 are the focus of future assessments; these are compared to the recent past period of 1981-2010. We characterize regional-scale temperature and humidity conditions using GCM output for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES) authored by the Intergovernmental Panel on Climate Change (IPCC). For each future period, 30 years of multi-model GCM output are analyzed to develop a ‘heat stress climatology’ based on statistics of extreme heat indicators. Differences between the two future and the past period are used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes are combined with the historical meteorological data, which is hourly and at a spatial scale (12 km) much finer than that of GCMs, to create future climate realizations at those scales. From these realizations, we compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air temperatures heat indices, and a new heat stress variable called the “Net Daily Heat Stress” that gives an integrated measure of heat stress (and relief) over the course of a day. Comparisons are made between the past and future climate periods to assess how climate change will impact heat stress across the United States (see illustrations).

One of the principal foci for this project is to integrate simulations of future heat stress statistics into the Center for Disease Control and Prevention’s (CDC) Wide-ranging Online Data for Epidemiologic Research (WONDER) system (http://wonder.cdc.gov/). Gridded datasets produced through this project have been aggregated to the county level, which is a popular scale of analysis for public health researchers, and were made available to decision makers through the WONDER website. CDC WONDER is an easy-to-use, menu-driven system that makes CDC information resources available to public health professionals and the public. WONDER’s website receives about 26 million web requests a year from over 600,000 distinct hosts. The addition of heat stress measures to CDC WONDER will allow decision and policy makers to assess the impact of alternative approaches to optimize the public health response to extreme heat events. It will also allow public health researchers and policy makers to better include heat stress measures in the context of national health data available in CDC WONDER. The users will be able to spatially and temporally query heat-related and public health data sets and create county-level maps and statistical charts of such data across the coterminous U.S.


INITIAL PROJECT ABSTRACT


Background:
In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. In keeping with NASA and the National Climate Assessment’s (NCA) guidance, the objective of this project is to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S.

Proposed Effort:
We will use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The project’s emphasis will be on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change will be captured with GCM output, and the temporal and spatial characteristics of short-term extremes will be represented by the reanalysis data.

Two future time horizons, 2040 and 2090, will be the focus of future assessments; these will be compared to the recent past period of 1981-2000. We will characterize regional-scale temperature and humidity conditions using GCM output for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM output will be analyzed to develop a ‘heat stress climatology’ based on statistics of extreme heat indicators. Differences between the two future and the past period will be used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes will be combined with the historical meteorological data, which is hourly and at a spatial scale (12 km) much finer than that of GCMs, to create future climate realizations at those scales. From these realizations, we will compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air temperatures, heat indices and a new heat stress variable that gives an integrated measure of heat stress (and relief) over the course of a day. Comparisons will be made between projected (2040 and 2090) and past (1990) heat stress statistics.

Results/Significance:
All output will be provided at the fine spatial scale and will also be aggregated to the county level, which is a popular scale of analysis for public health researchers. County-level statistics will be made available by our collaborators at the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. The CDC WONDER is an easy-to-use, menu-driven system that makes the information resources of the CDC available to public health professionals and the general public. This addition of heat stress measures to CDC WONDER will allow decision and policy makers to assess the impact of alternative approaches to optimize the public health response to EHEs. It will also allow public health researchers and policy makers to better include such heat stress measures in the context of national health data available in the CDC WONDER system. The users will be able to spatially and temporally query public health and heat-related data sets and create county-level maps and statistical charts of such data across the coterminous U.S.