Look to weather, climate changes

Key Points

• Extreme-rainfall events have increased during the past century, and those trends are expected to continue. Combined with land-cover changes, increased precipitation has and likely will continue to lead to flooding, erosion and declining water quality – and negative impacts on transportation, agriculture, human health and infrastructure.

• In the next few decades, longer growing seasons and increasing carbon dioxide levels will increase yields of some crops; those benefits will be progressively offset by extreme-weather events. In the long term, the combined stresses associated with climate change are expected to decrease agricultural productivity.

• The composition of forests in the Great Lakes is changing as the climate warms. Many tree species are shifting northward, with more southerly varieties replacing them. Many iconic north-wood tree species will lose their advantage and be slowly replaced during the next century.

• Increased heat-wave intensity and frequency, increased humidity, degraded air quality, reduced water quality and change in vector-borne disease patterns will increase public-health risks.

• The Great Lakes region has an extremely-energy-intensive economy, with per capita emissions of greenhouse gases more than 20 percent more than the national average. The region also has a large and increasingly utilized potential to reduce emissions that cause climate change.

• Climate change will exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of some species, increases in invasive species and harmful blooms of algae, and declines in beach health.

• Ice-cover declines will lengthen the commercial navigation season.

• At-risk communities in the Great Lakes are becoming more vulnerable to climate-change impacts such as flooding, drought and increases in urban heat islands. Tribal nations are especially vulnerable because of their reliance on threatened natural resources for their cultural, subsistence and economic needs. Integrating climate adaptation into planning processes offers an opportunity to better manage climate risks. Developing knowledge for decision-making in cooperation with vulnerable communities and tribal nations will help to build adaptive capacity and increase resilience.