Northeast annual average temperature has increased by 2Â°F since 1970, with winter temperatures rising twice this much. Warming has resulted in many other climate-related changes including more frequent very hot days, a longer growing season, an increase in heavy downpours, less winter precipitation falling as snow and more as rain, reduced snowpack, earlier break-up of winter ice on lakes and rivers, earlier spring snowmelt resulting in earlier peak river flows, rising sea surface temperatures, and rising sea level. These trends are projected to continue, with more dramatic changes under higher emissions scenarios compared to lower emissions scenarios. Some of the extensive climate-related changes projected for the region could significantly alter the regionâ€™s economy, landscape, character, and quality of life.
A note on the emissions scenarios
None of the emissions scenarios used in this report assume any policies specifically designed to address climate change. All, including the lower emissions scenario, assume increases in heat-trapping gas emissions for at least the next few decades, though at different rates.
Extreme heat and declining air quality are likely to pose increasing problems for human health, especially in urban areas.
By late this century under higher emissions scenarios, hot summer conditions would arrive three weeks earlier and last three weeks longer into fall. Cities that currently experience just a few days above 100Â°F each summer would average 20 such days per summer. Cities like Hartford and Philadelphia would average nearly 30 days over 100Â°F per summer. In addition, cities that now experience air quality problems would see those problems worsen with rising temperatures, if no additional controls were placed on ozone-causing pollutants.
Agricultural production, including dairy, fruit, and maple syrup, are likely to be adversely affected as favorable climates shift.
Large portions of the Northeast are likely to become unsuitable for growing popular varieties of apples, blueberries, and cranberries under higher emissions scenarios. The climate conditions suitable for maple/beech/birch forests are projected to shift dramatically northward, eventually leaving only a small portion of the Northeast with a maple sugar business and the colorful fall foliage that is part of the regionâ€™s iconic character.
Severe flooding due to sea-level rise and heavy downpours is likely to occur more frequently.
The densely populated coasts of the Northeast face substantial increases in the extent and frequency of storm surge, coastal flooding, erosion, property damage, and loss of wetlands. New York state alone has more than $2.3 trillion in insured coastal property. Much of this coastline is exceptionally vulnerable to sea-level rise and related impacts.
Ski Areas at Risk
under Higher Emissions Scenarioâ€
The projected reduction in snow cover will adversely affect winter recreation and the industries that rely upon it.
The length of the winter snow season would be cut in half across northern New York, Vermont, New Hampshire, and Maine, and reduced to just a week or two in southern parts of the region by late this century under a higher emissions scenario. Winter snow and ice sports, which contribute $7.6 billion annually to the regionâ€™s economy, will be particularly affected by warming.
The center of lobster fisheries is projected to continue its northward shift and the cod fishery on Georges Bank is likely to be diminished.
Lobster catches in the southern part of the region have declined dramatically
in the past decade, associated with a temperature-sensitive bacterial
shell disease. Analyses also suggest that lobster survival and
settlement in northern regions of the Gulf of Maine could increase
under warmer conditions. Cod populations, also subject to overfishing
and other stresses, are likely to be adversely affected as temperatures
continue to rise.