Climate Change

As climate has changed in the Lake Champlain Basin, lake ice has melted earlier in the spring.

Research has shown that climate in the Lake Champlain Basin is changing. Temperatures and precipitation have increased, and climate models predict that they will continue to rise in the coming decades. The average temperature in Vermont has increased by 2.7ºF since 1941, and the last decade has been the warmest on record. Temperatures in the Basin are projected to increase 3-6ºF by the middle of the century, and by 5.5-8ºF by the end of the century. Summer surface water temperatures in some parts of the Lake have risen as much as 6.8ºF since 1964. In winter, the number of days when the Lake is covered by ice is decreasing.

This changing climate is expected to result in more intense storm events (greater than one inch of precipitation per day). Heavy rainfall can affect water quality by increasing erosion in streambanks and other areas, and by causing combined sewer overflows. These events will deliver more nutrients, sediments, and pathogens to tributaries and the Lake. Increased flooding also will damage infrastructure and infrastructure. Warmer water temperatures can contribute to potentially toxic blue-green algae blooms, which threaten human health and reduces dissolved oxygen in the water available to fish and other aquatic organisms.

While many people are working to prevent or slow climate change, the focus of watershed managers in the Basin is on adaptation to climate change. Steps like allowing rivers to access their floodplains and implementing best management practices to minimize erosion will help to minimize the impacts of more frequent intense storms.