According to a January 2013 U.S. National Climate Assessment, a federal government report, the Northeast may experience the following scenarios under high carbon dioxide concentrations by the year 2100:
* In some cities, temperatures through nearly the entire summer will remain over 90 degrees Fahrenheit.
* Summer in Massachusetts could feel like the typical summer in South Carolina by the end of the century.
* Under the high emission scenario, average annual temperatures in the Northeast will rise three degrees Fahrenheit by 2039, seven degrees by 2069, and nearly 13 degrees by 2099.
* Increased flooding, less snow, changing forests, declining air quality, and more frequent droughts will lead to a different landscape in the Berkshires by 2100.
* By 2100, the health industry will be tested by the threats to human health as a result of climate change: Increasingly frequent and intense heat, more wildfires, diseases spread further by invasive species of insects, increasingly intense precipitation and flooding, and intensified air pollution will all lead to increasing health risks for those living in the Northeast with the elderly, the young, the chronically ill and the poor being the most at risk.
* Management of water supplies will become increasingly more challenging, with more frequent droughts and increased flooding changing the way water is captured, treated and delivered.
* "Climate change-driven perturbations to ecosystems that have direct human impacts include reduced water supply and quality, the loss of iconic species and landscapes, distorted rhythms of nature, and the potential for extreme events to eliminate the capacity of ecosystems to provide benefits," the report concludes. Released this month, a report by Environment Massachusetts’ research and policy center, a nonprofit environmental group, shows:
* Since 2007, federally declared weather-related disasters -- including Hurricane Sandy, severe winter storms and Tropical Storm Irene, affected all 14 Massachusetts counties.
* In 2012 alone, federally declared weather-related disasters affected Massachusetts counties housing more than 2 million people. Nationally, 11 weather disasters inflicted economic damages of $1 billion or more.
* Nationally, federally declared weather-related disasters have affected counties housing 243 million people since 2007-- or nearly four out of five Americans.
* The U.S. has experienced an increase in heavy precipitation events, with the rainiest 1 percent of all storms delivering 20 percent more rain on average at the end of the 20th century than at the beginning.
* The trend toward extreme precipitation is projected to continue, even though higher temperatures and drier summers will likely also increase the local risk of drought in between the rainy periods.
* Records show that the U.S. has experienced an increase in the number of heat waves over the last half-century. Scientists project that the heat waves and unusually hot seasons will likely become more common.
* Hurricanes are expected to become even more intense and bring greater amounts of rainfall, even though the number of hurricanes may remain the same or decrease.