As area's heat index regularly exceeds 90 degrees, weather experts are telling us that the last year has been the warmest on record in the United States. Extreme weather events “of the recent past,” like heat waves and droughts, are caused by climate change, reported climate scientist James Hansen and several of his colleagues in an August 6 study.

They maintain that in the last three decades, as the average temperature has risen, “the extremes have soared and now cover about 10 percent of the globe,” Hansen wrote in the Aug. 5 edition of the Washington Post. He is a scientist for the Goddard Institute for Space, NASA and a professor at Columbia University.

This study follows an Environment Virginia study in July that found that incidences of extreme precipitation are occurring 33 percent more frequently in Virginia since 1948, based on National Climatic Data Center information. The authors cited as an example a 2011 downpour in Northern Virginia during which 12 inches of rain pummeled the area.

This group said that heavy rain or snowstorms that used to occur once every 12 months, on average, in the state now happen every nine months on average. They also contend that from 1948 to 2011, the amount of precipitation in Virginia increased by 11 percent.

The Virginia Commission on Climate Change in 2008 predicted a 2.3- to 5.2-foot sea level rise per century in the Chesapeake Bay region. Among other recommendations, the commission supported reductions in heat-trapping greenhouse gas emissions in the state, noting that coal represents 83 percent of all greenhouse gases from electricity production in Virginia.

Global Warming to Affect Potomac River Communities

Without action, the Potomac River could rise by 2 feet by 2050 or, with a surge, by 4 feet, say National Oceanic and Atmospheric Administration experts. In March, a study by Climate Central, titled “Surging Seas,” reported that along the shores of the tidal Potomac River, sea level rise increases the risk of a 100-year flood from 16 percent to 19 percent by 2030. 

Many attribute rising sea levels to climate change. “The shorelines of the Chesapeake Bay and its tributaries, such as the Potomac River, are among the region’s most threatened resources ... ,” the Metropolitan Washington Council of Governments (COG) reported in 2009. 

COG concluded that the Potomac estuary has experienced 1 foot of sea level rise over the last century and projected that the trend will continue at an increased rate, leading to “expanded riparian flood plains and coastal inundation zones and more frequent droughts, heat waves and record-setting events.”  Impacts could include more frequent travel disruptions, increased damage to buildings, sanitary sewer overflows and adverse health impacts from flooding, storms, extreme heat and more poor air quality days.

In a 2009 analysis, Fairfax County staff told the board of supervisors that coastal flooding will become more frequent and will expand in areas like Cameron Run, Hunting Creek, New Alexandria and Belle View in northern Mount Vernon. Land and wetlands along the Potomac could be inundated. The New Alexandria tide gate and pumping station could be vulnerable. More intense storms could overwhelm stormwater facilities and flood roads and other infrastructure, these analysts advised.

County staff recommended that the county base what are called “adaptation strategies” on a projection of a rise of 1 to 1.6 feet in the sea level by 2050, incorporate sea level rise in some building designs and evaluate sea level rise impacts in flood protection projects in coastal areas and other steps.

Fairfax County Board of Supervisors Chairwoman Sharon Bulova said recently, “Fairfax County is taking proactive steps to address the impact of environmental change on our community, including rising sea levels. The county recognizes the potential impact of sea level rise as a an ongoing concern and is committed to working closely with partners in the federal, state, and local government to develop appropriate measures, including policies and regulations to safeguard critical infrastructure and protect our residents from those impacts.”

COG Director of Environmental Programs Stuart Freudberg had this to say:  “COG is taking a two-track approach to the issue of climate change: reduce and adapt. We know we’ve got to reduce our greenhouse gas emissions and we’ve laid out clear goals to do so – reducing regional emissions by 20 percent below 2005 levels by 2020 and by 80 percent by 2050.

"We’ve also done a lot of work to educate elected leaders and local government officials on strategies for adaptation of climate change. These strategies can be useful for combating the direct effects of climate change as well as storms and natural disasters occurring with greater frequency.”

A few facts:

• Northern Virginia gets half of its electric power from coal plants, a major source of greenhouse gas emissions.
• Virginia ranks 34th in energy efficiency among states, according to the American Council for an Energy-Efficient Economy.
• If growth continues as projected by COG, emissions from energy consumption will jump by 35 percent by 2030 and 43 percent by 2050. 

For more information on climate change in Virginia, visit the
Virginia Institute for Marine Science http://ccrm.vims.edu/coastal_zone/climate_change_db/index.html and http://www.sealevelrisevirginia.net/main_CCC_files/; in the Washington area, http://www.mwcog.org/environment/climate/adaptation.asp.

The Hansen study, published by the National Academy of
Science, is posted here.