Agriculture

The frequency, intensity, and duration of heat waves is expected to increase for the Northeast. Much of the southern portion of the region, including the majority of Maryland and Delaware, and New Jersey and West Virginia, are projected by mid-century to experience more than 18 additional days per year above 95°F compared to the end of last century, under a high emissions scenario

Climate models under a high emissions scenario indicate temperatures will increase by 4.5F° to 10°F by the end of the century, whereas climate models under a low emissions scenario project temperature increases from about 3°F to 6°F by the end of the century.

Heavy precipitation events have been increasing in number and severity in the upper Midwest in general and for Minnesota in particular, and many models agree that this trend will continue over the next century. For example, storms in the 99th-percentile category incrased by 42% from 1958 to 2016 across the Midwest. Large storms are also expected to deliver more rainfall as well. In the Midwest, 20-year return storms are projected to deliver 11 to 20% more rainfall by the end of the century. Most heavy precipitation events occur during summer in the Upper Midwest.

Evidence at both global and local scales indicates that growing seasons have been getting longer, and this trend is projected to become even more pronounced over the next century. As seasons shift so that spring arrives earlier and fall extends later into the year, phenology may shift for plant species that rely on temperature as a cue for the timing of leaf-out, reproductive maturation, and other developmental processes. Longer growing seasons could also result in greater growth and productivity of trees and other vegetation, but only if balanced by available water and nutrients.

Cold-season soil temperatures are projected to increase between 1.8 and 5.4 °F by the end of the century, and total frost depth is projected to deline by 40 to 80 percent across northern Wisconsin and western Upper Michigan by the end of the century. These conditions could increase water infiltration into the soil and reduce runoff, but they may also lead to greater soil water losses through increased evapotranspiration.

A variety of models project that across the Upper Midwest, more winter precipitation will be delivered as rain, more snow will melt between snowfall events, and the snowpack will not be as deep or consistent. Lake-effect snowfall may increase in the short-term, but these events may convert to rain as temperatures increase.

Soil moisture is expected to change in response to warmer temperatures and seasonal changes in precipitation. Changes are likely to vary seasonally as well as geographically. More intense and prolonged precipitation events would be expected to create wetter soil conditions, while increased temperatures and less frequent rainfall events would lead to drier soils .

A variety of models project that winters will become more mild across New England and northern New York as temperatures increase. Warmer temperatures will cause more winter precipitation to be delivered as rain. Snowfall, snow depth, and snow pack duration are all expected to be reduced.

Shorter-term fluctuations in the variability of ocean dynamics, atmospheric shifts, and ice mass loss from Greenland and Antarctica have been connected to recent accelerations in the sea level rise rate in this region. Sea levels have risen over the past century, and all global climate models agree that sea level will rise over the next century. Worst-case and lowest-probability scenarios project that sea levels in the region could rise upwards of 11 feet (3 m) on average by the end of the century.

Heavy precipitation events have increased substantially in number and severity in the across the Northeast over the last century, and many models agree that this trend will continue over the next century. Extreme precipitation events could lead to more frequent or severe flooding and an increase in soil erosion. Monthly precipitation in the Northeast is projected to be about 1 inch greater for December through April by end of century (2070–2100) under a high emissions scenario.