Report: Northeast to Warm at Least 3º by 2080

Increase in Days Above 95 Degrees in Northeast, Climate ChangeEven with a significant reduction in greenhouse gas emissions over the coming decades, the Northeast will see its average temperature increase at least 3-6ºF by the 2080s. The troubling numbers were released late last week in a massive draft climate report issued by a 60 person National Climate Assessment and Development Advisory Committee.

The report, which was constructed by more than 200 authors, estimates Northeast warming will reach 4.5-10ºF by the 2080s if greenhouse gas emissions continue to increase.

Warming of that magnitude would increase the frequency, duration, and intensity of Northeast heat waves, while decreasing the frequency of cold air outbreaks. Around Greater Boston we can expect 3-6 more days per year to hit 95 degrees or greater by century’s end (image at left). Heavy precipitation events are also expected to increase.

Between 1895 and 2011 the Northeast saw a temperature increase of 2ºF. Precipitation increased 5″, and sea levels increased by a foot. The rate of sea level rise, in fact, surpasses the global average of just 8″.

The rate of sea level rise in the Northeast beats the global average because of land subsidence, and partially because of a weakening Gulf Stream current according to new research.

By 2100, Northeast sea levels are projected to increase another 1 to 4 feet. The new report expects this rise to turn a now 1-in-10 year coastal flood event into a 1-in-3 year flood event. For major population centers along the coast, this could be devastating and costly, especially to already aging infrastructure.

Across the United States as a whole, the report asserts that climate change is already affecting Americans. Temperatures nation-wide have increased 1.5º since 1895, with 80% of the warming since 1980. Changes, of course, are not uniform in every location. Higher latitude locations are impacted the most.

Over the coming decades, warming of at least 2-4º is expected nation-wide. If greenhouse gas emissions continue to rise, the report warns that average temperatures may spike 5-10ºF.

Climate change was the topic of many sessions at last week’s American Meteorological Society Annual Meeting, which I attended. Please read my summary of the conference here.