Over the next few weeks, S&S will be bringing you a summary of regional climate change impacts expected across the United States over the next century, according to the National Climate Assessment (NCA) published by the White House in early May. Building off of the first post on the overall impacts expected across America, this segment focuses on the specific impacts of climate change for states in the Northeast and the Southeast regions. The most important takeaways from the NCA for each region are summarized below.
Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, West Virginia, and the District of Columbia
Residents of the Northeastern United States will face significant increases in precipitation, flooding and heat waves as the climate begins to warm. Already, temperatures in the Northeast have warmed almost 2° F and sea level has risen one foot in the past century. This region has also experienced the greatest increase in extreme precipitation in recent years, with a 70% increase in the amount of precipitation falling in “very heavy events” since 1958. If emissions continue to increase, warming of 4.5° F to 10° F is projected by the 2080s; even if global emissions were reduced substantially, projected warming still ranges from about 3° F to 6° F by the 2080s. With 64 million people residing in some of the densest urban areas in the country and farmland generating $17 billion in annual sales, this region is highly vulnerable to the impacts of climate change. Among the major concerns are:
- More frequent and more severe heat waves: Under both high and low emissions scenarios, the duration of heat waves is expected to increase in the Northeast. States in the southern part of the region will experience significantly more days over 90° F by the end of this century compared to the end of last century.
- Precipitation increase: The amount of precipitation, especially in the winter and the spring, is likely to increase throughout the course of the century. Models predict 5-20% increases in winter precipitation in the Northeast by 2100. Despite expected warming, this still means winters of even heavier snow for many northern states in the region. In the summer and winter, there is a slightly smaller (but still measurable) predicted increase in heavy downfalls and potential for flash flooding.
- Sea level rise brings more dangerous coastal flooding: Overall global sea level is expected to rise 1-4 feet by 2100, an estimate that is recently even being called conservative given new changes in the Antarctic and Greenland ice sheets. A sea level rise of only two feet would more than triple the frequency of dangerous coastal flooding in the Northeast, exacerbating the impacts of extreme weather events such as the recent onslaught of hurricanes in the region.
These impacts of climate change in the Northeast will be detrimental for residents, infrastructure, agriculture and ecosystems in the area. Additionally, with the country’s financial and political capitals housed in this region, the country as a whole is vulnerable to any impacts that may occur in the Northeast. Planning and adaptation has already begun, with 11 of the 12 states having developed adaptation plans for several sectors, and 10 in the process of releasing statewide adaptation plans. Notable activities include the Regional Greenhouse Gas Initiative to reduce the amount of greenhouse gases produced by Northeastern industries, risk assessments of infrastructure, and research and outreach efforts to help farmers find ways to adapt to the rapidly changing climate.
Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Puerto Rico and the U.S. Virgin Islands
The Southeast’s biggest concerns with climate change revolve around water – both too much and too little of it. With some of the lowest-lying land in the country, the Southeast is the most vulnerable region of the United States to sea-level rise, which has the potential to make some areas permanently uninhabitable. Simultaneously, significant and extended heat waves in other parts of the Southeast will threaten agriculture and human health, while making drinking water increasingly scarce. Another complicating factor is that the Southeast is one of the biggest energy-producing regions in the US, and is the highest energy user of any region in the country. While temperatures in the Southeast have fluctuated more over the past century than in the Northeast, they have been increasing since 1970 and are now averaging 2° F higher than 40 years ago. Notable concerns in the Southeast include the following:
- Sea level rise threatens built environments and growing economies: As the rate of global sea level rise is expected to increase over the next century, portions of the Southeast are especially vulnerable. Roughly half of the population of New Orleans currently lives below sea level and is considered at very high risk of irreversible flooding. Miami, Tampa, Charleston and Virginia Beach are also among those most at risk. The coastline of Puerto Rico is also already eroding at a rate of 3.3 feet per year. With sea level rise comes damage to homes and infrastructure from flooding, contamination of freshwater drinking supplies, impacts on the vulnerability of offshore energy capture, and the degradation of freshwater ecosystems inundated with sea water.
- Increased frequency, duration and severity of heat waves: Atlanta, Miami, New Orleans, and Tampa have already had increases in the number of days with temperatures exceeding 95° F. Heat has been shown to have highly detrimental effects on human cardiovascular, cerebral and respiratory systems, and these extended heat waves have resulted in higher than average number of hospitalizations and deaths. Other impacts of increased heat include more mosquitos that can carry diseases such as malaria and West Nile Virus, harmful algae blooms in coastal waters and fish poisoning, reduced land available for agriculture and stresses on livestock and crop production.
- Decreased freshwater availability: The Southeast is home to growing, sprawling urban areas and an unfortunate vulnerability to extensive droughts. Expected increase in evaporation due to rising temperatures and high growth in residential, commercial and agricultural areas will put added pressure onto water sources in the region, exacerbated by saltwater intrusion due to rising sea levels. Areas in the west of the region are the most vulnerable, as are dense urban areas in the region that are some of the fastest growing metropolitan areas in the country.
To face the challenges of climate change, the states in the Southeast will need to consider both adaptation and long-term behavior modifications. Currently the region uses the most electricity out of any region in the United States, due to both climate and cultural forces. This will put significant stress on energy infrastructure as demand for air conditioning increases with higher temperatures. While some regions may become uninhabitable depending on the amount of sea level rise, local governments will have to increase innovation to continue inhabiting several of the sea level rise and drought-stricken areas. Notable adaptations thus far have included infrastructure changes such as the raising of roads in coastal North Carolina and innovating solutions such as a water recycling system in Georgia. Regional cooperation will also be vital to the effort to curtail sea level rise throughout the Southeast.
Our next post will look at the climate change impacts to the Midwest, Great Plains and the Southwestern United States.
Image Credit: Metropolitan Transport Authority of the State of New York via Wikimedia Commons