The U.S. Drought Monitor shows the extent of current drought conditions.
Click on the map above to go to the drought monitor site with a full report and statistics.
Drought and Climate Change
Recent U.S. droughts have been the most expansive in decades. At the peak of the 2012 drought, an astounding 81 percent of the contiguous United States was under at least abnormally dry conditions, resulting in an estimated $30 billion in damages. Climate change increases the odds of worsening drought in many regions of the U.S. and the world in the decades ahead.
Global warming will increase the risk of drought in some regions, particularly in the Southwest United States. Even in regions that may not see changes in precipitation, warmer temperatures can increase water demands and evaporation, putting greater stress on water supplies.
Estimates of future changes in seasonal or annual precipitation in a particular location are subject to considerable uncertainty; more so than estimates of future warming. However, scientists are more confident that at the global scale, relatively wet places such as the tropics and the high latitudes will get wetter, while relatively dry places in the subtropics (where most of the world’s deserts are located) will become drier.
When droughts do occur, warmer temperatures can amplify their impacts. Droughts can persist through a “positive feedback,” where very dry soils and diminished plant cover can further suppress rainfall in an already dry area. Increased temperatures enhance evaporation from soils, making a periodic occurrence of drought worse than it would be under cooler conditions.
Threats to the U.S.
The United States is historically susceptible to drought. Paleoclimate studies show major droughts in the distant past, while some more recent dry periods are still within living memory, such as the Dust Bowl of the 1930s or the drought of the 1950s. These historic examples serve as guideposts to highlight our vulnerabilities to drought as we move into a warmer, and in some places, drier future.
Recent U.S. droughts have been the most expansive in decades. For example, in 2011, Texas experienced its driest 12 months ever. At one point, 80 percent of the state was rated at an “exceptional” level of drought. At the peak of the 2012 drought, an astounding 81 percent of the contiguous United States was under at least abnormally dry conditions. Severe drought can affect:
- Agriculture: Droughts affect livestock and crops, including cornerstone commodities like corn, soybeans and wheat. At the height of the 2012 drought, the U.S. Department of Agriculture declared a natural disaster over 2,245 counties, 71 percent of the United States.
- Transportation: Recent droughts have had major impacts on water levels on the Mississippi River and the ability to move goods along the river. Transport barges need at least nine feet of water, and to maintain this level, the U.S. Army Corps of Engineers had to blast, dredge, and clear obstructions on a key stretch between St. Louis, Mo., And Cairo, Ill.
- Wildfires: In the Southwest, drought conditions and record heat have fueled damaging and sometimes deadly wildfires in Arizona, Colorado and New Mexico. Millions of forested acres and thousands of homes have been lost over the past decade due to fires thriving in dry, stressed forest environments and because of the proximity of communities to fire-prone forests.
- Energy: Droughts can raise concerns about the reliability of electricity production from plants that require cooling water to maintain safe operations. When heat waves coincide with droughts, electricity demands can grow, compounding stress on the grid.
Potential Global Problems
In recent years, droughts have struck several major breadbasket regions simultaneously, adding to food price instability. In countries already facing reduced food security, cost spikes can lead to social unrest, migration, and famine. Several price spikes have occurred over the last decade, often connected to crop failures or poor yield. During the 2007-2008 crisis, the Food and Agriculture Organization of the United Nations estimated that high food prices increased the number of chronically hungry people in the word by 75 million.
How to Build Resilience
Governments and businesses must identify the vulnerabilities that droughts expose and take steps to improve resilience. Actions like using water more efficiently and developing more drought-resistant crops will help prepare us for both future droughts and climate change. These steps will be most effective if they are combined with reductions in greenhouse gases that can minimize the ultimate magnitude of climate change.
To Learn More
As with any single event, Hurricane Isaac doesn’t tell us anything about whether hurricanes are getting worse due to climate change. But Isaac’s impacts should be examined to teach us about our vulnerabilities to the types of extreme events scientists tell us climate change will make more common.
The loss of Arctic sea ice is progressing more rapidly and clearly than just about any other indicator of global climate change. As I’ve discussed previously, the minimum summer sea ice extent (i.e. the two-dimensional area of the floating ice cap) set new record lows in 2002, 2005 and 2007. Similarly, the total volume of sea ice set record lows in 2007, 2010 and 2011. For the first time since 2007, both the sea ice extent and volume have set new record lows in the same year (see figures). And what’s more, they did it with weeks remaining in the melt season, which usually ends in mid-September. So the records have been broken this year, but we don’t know yet just how low the extent and volume will go.
July 31, 2012
Contact: Laura Rehrmann, 703-516-0621, email@example.com
C2ES Releases New Extreme Weather Map on Eve of Senate Climate Hearing
The Center for Climate and Energy Solutions (C2ES) has created a new online map providing an overview of extreme U.S. weather events since 1990. The map highlights examples of extreme heat, heavy precipitation, drought, and wildfire -- four types of events with clear trends connected to climate change.
In a blog post announcing the new map, C2ES science and policy fellow Dan Huber summarizes the recent run of extreme weather:
- The last 12 months were the hottest on record for the lower 48 states by a significant margin. The “Summer in March” heat wave broke thousands of heat records across the country.
- Almost as soon as the spring heat subsided, wildfires sprang up in the West, with New Mexico’s largest wildfire on record and Colorado’s most damaging fire occurring within weeks of each other.
- The United States is mired in the most extensive drought since 1956. Nearly two-thirds of the contiguous U.S. is currently in drought and 75 percent of that area is categorized as severe. Last year, Texas had its most severe drought ever, resulting in billions of dollars in agricultural losses.
“Climate change is elevating the risk of extreme weather,” writes Huber. “It’s crucial that we take stock of what each disaster teaches us so that we understand the rising risks and are better prepared for what’s to come.”
The science behind climate change will be the focus of a hearing tomorrow (Wednesday, Aug. 1) before the Senate Environment and Public Works Committee titled “Update on the Latest Climate Change Science and Local Adaptation Measures.” The hearing, set for 10 a.m. in 406 Dirksen, is the Senate’s first in this Congress focusing directly on climate change science.
For more information:
Extreme weather map: http://www.c2es.org/science-impacts/extreme-weather
Climate Compass blog: http://www.c2es.org/climatecompass
Contact Senior Communications Manager Laura Rehrmann at firstname.lastname@example.org to arrange an interview with a C2ES expert.
About C2ES: The Center for Climate and Energy Solutions (C2ES) is an independent non-profit, non-partisan organization promoting strong policy and action to address the twin challenges of energy and climate change. Launched in November 2011, C2ES is the successor to the Pew Center on Global Climate Change.
Despite the very different views of the majority and minority parties in the Senate, there was in fact a fair degree of agreement among the witnesses at today’s hearing on climate science and local adaptation.
During the climate science portion of the Senate Environment and Public Works Committee hearing, both the majority and minority witnesses agreed that the Earth has warmed over the past 120 years. With the recent publication of the Berkeley Earth Surface Temperature project by former skeptic Richard Muller, there are now four (NOAA, NASA and Hadley are the others) major global temperature records that are in agreement that the Earth has warmed 1.5 degrees Fahrenheit over the past 50 years.
Today’s Senate hearing isn’t just about the science of climate change. It’s also about the actions that need to be taken now to adapt to the reality of a changing climate. Businesses and governments each have a critical role to play in building resilient communities and economies.
Business-as-usual is already being interrupted by extreme heat, historic drought, record-setting wildfires, and flooding. Events from water shortages to floods are disrupting the supply chains for such companies as Honda, Toyota, Kraft, Nestle and MillerCoors. By the end of 2011, the United States had recorded more billion-dollar disasters than it did during all of the 1980s, totaling about $55 billion in losses.
The Senate Environment and Public Works Committee holds a hearing tomorrow called “Update on the Latest Climate Change Science and Local Adaptation Measures.” This is the first Senate hearing focused directly on climate science in the 112th Congress, and we hope it won’t be the last. Climate change is happening, the news from peer-reviewed science is increasingly daunting, and the public needs to hear what credible scientists are learning about the risks and potential solutions.
Today we’re updating our online map providing an overview of extreme weather events in the United States since 1990. The map highlights memorable examples of extreme heat, heavy precipitation, drought, and wildfire, four types of events with clear trends connected to climate change.
I recently responded to a question on the National Journal blog, "Does climate change cause extreme weather like the heat waves much of the country has been enduring for the past few weeks?"