[In the weeks ahead, BNA’s climate blog will take a closer look at U.S. regions covered in the draft National Climate Assessment. In addition to the Northeast, regions covered in the assessment include the Southeast and Caribbean, Midwest, Great Plains, Southwest, Northwest, Alaska and the Arctic, and Hawaii and U.S. Affiliated Pacific States.]

The main message in the draft National Climate Assessment for the Northeast United States is clear. Expect more sea-level rise, coastal and river flooding, intense precipitation events, and higher temperatures. All populations will be at increased risk, especially the disadvantaged.

In response to climate change, the Northeast, made up of high-density urban and coastal areas as well as substantial agricultural lands, will need to step up adaptation efforts, according to the draft assessment released by a federal advisory committee Jan. 11.

As detailed in a World Climate Change Report article published Jan. 11, the draft, released by the National Climate Assessment and Development Advisory Committee, is not yet an official federal document. It will become so once it’s submitted to the National Science Technology Council sometime this fall. The council is expected to review, modify, and approve a final draft by Jan. 30, 2014. A national assessment on climate science and climate change impacts is due to Congress every four years under the Global Change Research Act of 1990. However, only two reports have been completed since the law passed, one in 2000 and the other in 2009.

Temperature, Precipitation, Sea-Level Rise

While temperatures will rise between 2 and 4 degrees Fahrenheit in most of the United States in the next few decades, according to the draft assessment, the Northeast is expected to see even greater temperature increases. If greenhouse gas emissions remain on their upward trajectory, temperatures may rise between 4.5 to 10 degrees Fahrenheit by the 2080s or between 3 and 6 degrees Fahrenheit under a lower emissions scenario.

In addition, the Northeast should prepare for extreme heat events, according to the draft. And, while the heat island effect may result in a greater health impacts in urban areas, rural and small town residents where air conditioning may not be prevalent also may be adversely affected by heat waves. Increased levels of air pollution resulting from increased temperatures will further exacerbate ill health effects, especially in vulnerable populations such as the elderly, the young, and those with weak immune systems.

Changes in precipitation are less certain but heavy downpours will likely continue, the draft assessment found. Between 1958 and 2010, the Northeast saw a 74 percent increase in the amount of precipitation falling during very heavy events. Drought conditions also are expected to increase during summer and fall, stressing agriculture and ecosystems.

Sea-level rise in the Northeast is expected to exceed the global average of between one and four feet by 2100 by at least 4 inches, or more if the Gulf Stream weakens as some models suggest, the draft said. Even on the low end, rising sea levels are expected to increase one-in-ten-year flooding events to one-in-three-year events.

Hurricanes Sandy, Irene Covered in Report

One has to look no further than Hurricanes Irene and Sandy, according to the draft assessment, to understand the region’s vulnerability and how existing and evolving climate change adaptation plans measure up.
The most severe impacts of Irene, which hit the Northeast in August 2011, were inland, especially in upstate New York and central and southern Vermont, according to the draft assessment. The flooding affected roads, bridges railroads, and power lines. Hazardous waste was released in a number of areas and municipal wastewater treatment plants were breached. Agricultural losses included damage to farm structures and flooded fields of crops.

Hurricane Sandy, which made landfall in the Northeast in October 2012, became one of the most damaging storms to strike the continental United States, according to the draft. In addition to killing more than 100 people, the storm disrupted daily life for millions of coastal-zone residents across the New York-New Jersey metropolitan area and other areas across the east to Chicago. Destruction of property and critical infrastructure has been estimated to be in the tens of billions of dollars.

Region Ahead of United States

Compared to the rest of the United States, the Northeast is ahead of the game in planning for climate change. Of the 12 states in the Northeast, 11 have developed adaptation plans for several sectors and 10 have released or plan to release statewide plans, according to the draft assessment. In addition, several municipalities have begun to incorporate climate change risk in planning activities.

For example, the effects of Hurricane Sandy in New York would have been far worse if local climate resilience strategies such as those included in its sustainability plan known as PlaNYC had not been in place, the draft assessment said. PlaNYC, which was adopted in 2007, coordinates work on climate change, green buildings, and other energy and environmental projects, such as elevating structures out of floodplains.

However, implementation of most adaptation measures in the Northeast is still in the early stages and will require major expenditures and structural changes over the long-term, the draft found, and multi-state coordination could help implement adaptation strategies and reduce redundancies in planning.

The assessment pointed to a well-known planning tool developed by the New York City Panel on Climate Change and adopted by the Committee on America’s Climate Choices in which an eight-step iterative approach is used by decisionmakers to design a “flexible adaptation pathway” to address infrastructure, such as communication systems, energy production, transportation, and water supplies, along with other issues, by taking an inventory and assessment of risks posed by climate change.

The key, with respect to infrastructure, the draft assessment said, is to link adaptation strategies with capital improvement cycles to adjust plans to incorporate emerging climate projections.