Last month, the fourth National Climate Assessment for the United States was released to the public.
This NOAA led report is based off of the latest peer-reviewed scientific literature, complemented by other sources where appropriate. In addition, authors used well-established and carefully evaluated observational and modeling datasets, technical input reports, USGCRP's sustained assessment products, and a suite of scenario products. Each source was determined to meet the standards of the Information Quality Act.
The report is quite long, so I am breaking it down the report by regions in the U.S.. Today I will focus on what the report has to say about the current and future impacts of climate change on the region through the end of this century.
--By 2035, the northeastern U.S. is projected to warm more than 2 deg. C (3.6 deg F.) above pre-industrial levels. This is about two decades faster than the global average based on the most likely global emissions scenarios.
--Winters have warmed three times faster than summers in the northeastern U.S.
--Fewer cold extremes are anticipated by mid-century.
--Early emergence of plants can make them more susceptible to later cold spells as their tolerance to cold air is reduced.
--Many deciduous trees are projected to experience an overall increase in their amount of autumn foliage color.
--More intense precipitation events have increased the risk of some types of inland floods in the region, especially in valley locations.
--Many of the larger cities in the Northeast, especially New England, were developed along rivers, canals and on the coast. The predicted increase in flood frequency or severity could increase the spread of contaminants into waterways, which can result in greater risks to health of nearby ecosystems, animals and people.
--Precipitation is expected to increase during winter and spring but with little change in summer.
--Less early winter snowfall and earlier snowmelt is predicted, based on the latest climate projections for this region. This will also result in decreased snow depth and a shorter snow season with fewer days of snow on the ground.
--The proportion of winter precipitation falling as rain has already increased across the Northeast and will likely continue to do so.
--The report also expects a trend toward less lake ice.
--The earlier snowmelt and related runoff may lead to lower spring peak streamflows for the 2014-2095 period compared to the 1951-2005 period.
Ski resort impacts
--Activities that rely on natural snow and ice cover are projected to remain economically viable in only far northern parts of the region by the end of the century under the higher greenhouse emissions scenario. This will put even more focus on more costly man-made snowmaking capabilities.
--However, the capacity of some vulnerable southern and low-elevation locations to adapt in the long-term is expected to be limited by higher nighttime temperatures.
Impact on Northeast U.S. agriculture
According to the report, the Northeast agriculture sector will benefit from the changing climate over the next half century due to greater productivity over a longer growing season.
However, excess moisture is already a leading cause of crop loss in the Northeast (waterlogged fields).
In addition, warmer winters are not killing off as many pests, which is leaving a higher number of pests to attack crops during the growing season.
Image courtesy NOAA.
--The coastal waters along the Northeast continental shelf warmed at a rate of 0.033 deg. C (0.06 F.) per year from 1982 to 2016, which is three times faster than the global average. This increase in warming has been greatest during the summer months.
--Sea level rise along the Middle Atlantic and northeastern U.S. coast has been three to four times higher than the global average.
--There has been a 100 to 200 percent increase in high tide flooding in some coastal locations.
--The report projects anywhere from a 2- to 4.5-foot increase in sea-level along the Northeast coast by the end of this century.
It is obvious that climate change adaptation efforts by local, state and federal governments will be critical from now through the end of this century.