Impacts of Climate Change Could Strongly Increase by Mid-Century

Environmental models employed by researchers at the University of New Hampshire are demonstrating that the effects of climate change could become increasingly strong by the middle of the 21st century, a warning to nature lovers. These models also show that a number of weather and ecosystem conditions could steadily decline more in the future.

If carbon dioxide emissions continue at the existing rate, they report that situations of future conditions could not just lead to a major decrease in snow days, but could result in an increase in the number of summer days over 90^o and a severe decline in stream habitat with 40% not suitable for cold water fish.

While this research was applied to New Hampshire, the approach can be generally applied, and a number of things that people care about will worsen due to climate change, for example, right now the average number of snow days is 60 per year, but in 20 to 30 years the models show that the number of snow days could be as low as 18 days per year.

Wilfred Wollheim, associate professor in the department of natural resources and the environment and one of the study’s authors.

The research, featured recently in the journal Ecology and Society, employed models bench marked to field measurements in order to assess the Merrimack River watershed in New Hampshire. They discovered that together with a decrease in snow cover in the winter, other possible impacts could comprise of up to 70 hot summer days each year with temperatures of 90^o or more by the end of century, a bigger probability of flooding, a significant loss of cold water fish habitat, and increased nitrogen inputs to coastal areas which could result in eutrophication, referring to an irregular amount of nutrients capable of polluting the water and depleting fish species. Researchers explain that the largest impact will be around urban areas, close to where people live.

Land use and population growth interacting with climate change are also important drivers, these models can help guide efforts to make plans to adapt to the changing climate. Alterations in land use policy could reduce these impacts. In particular, prevention of sprawl and investment in storm and waste water infrastructure would further maintain more ecosystem services. Implementing policies that reduce greenhouse gas emissions are essential to limit even further changes.

Wilfred Wollheim, associate professor in the department of natural resources and the environment and one of the study’s authors.

According to the researchers, this study is the first time a model such as this has been applied to New England watersheds that constantly account for land use change, climate change, aquatic ecosystem processes and forest ecosystem processes, including inconsistency in weather that takes place within years (storm and seasonal) and across years, to evaluate a whole suite of differences simultaneously.

This research has been funded by NSF EPSCoR Ecosystems and Society (#EPS 1101245). A part of the funding was provided by the National Sea Grant College Program of the U.S. Department of Commerce’s National Oceanic and Atmospheric Administration grant NA10OAR4170082 to the N.H. Sea Grant College Program, and by the New Hampshire Agricultural Experiment Station (NHAES) through USDA National Institute of Food and Agriculture Hatch Project 0225006. This is NHAES Scientific Contribution Number 2736.