How and why is climate change impacting the Great Lakes? How is it affecting our future? What are we doing about it?
As part of its fifth assessment report published in 2013, the Intergovernmental Panel on Climate Change says “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.” The World Economic Forum, in its Global Risks Report this year, also recognized the failure of climate change mitigation and adaptation “as the most impactful risk for the years to come, ahead of weapons of mass destruction.”
Climate change is posing significant risks to communities, health and well-being, the economy, and the natural environment. These impacts are expected to become more severe, unless concerted efforts to reduce emissions are undertaken.
Climate change effects are being experienced in the Great Lakes. Effects observed across the basin include warming temperatures, changing precipitation patterns, decreased ice coverage, and variations to historic fluctuations of water levels. For example, over the last 60 years (1950-2010), the Great Lakes basin has experienced an increase in average annual air temperatures between 0.8-2.0 degrees C (1.4-3.6 F), with this warming trend projected to continue, according to a 2015 State of Climate Change Science in the Great Lakes basin report.
In the last century, surface water temperatures of the Great Lakes have increased by as much as 3.5 degrees C (6.3 F) and are projected to continue to increase. More work is needed to understand the full impact of these changes on Great Lakes water quality and the health of the aquatic ecosystem.
Recognizing the potential impacts of climate change on Great Lakes water quality and ecosystem health, Canada and the United States incorporated a Climate Change Impacts Annex in the 2012 Great Lakes Water Quality Agreement (GLWQA). The Annex is focused on coordinating efforts to identify, quantify, understand, and predict climate impacts on the quality of waters of the Great Lakes, and sharing information that Great Lakes resource managers need to proactively address these impacts. Implementation of this Annex is led by Environment and Climate Change Canada and US National Oceanic and Atmospheric Administration.
Over the first three years of implementation of the 2012 GLWQA, the work under this Annex focused on a review of the current and best available, peer-reviewed climate change science relevant to the Great Lakes. The “State of Climate Change Science in the Great Lakes Basin: A Focus on Climatological, Hydrologic and Ecological Effects” synthesizes the state of climate change impacts in the Great Lakes basin and identifies key knowledge gaps and provides a foundation of knowledge that will guide future work under this Annex.
In addition, a new product known as the “Great Lakes Climate Quarterly” was developed for use by government managers and practitioners, as well as stakeholders and the public. These quarterlies are available at binational.net and provide a quick and easy-to-understand overview of the latest season’s weather and water level conditions, weather and water level-related impacts, and an outlook for the upcoming quarter. Canada and the US also have a number of other interesting projects underway that are of value to this Agreement, including the Great Lakes Evaporation Network and the Lake Level Viewer.
For the next three years, the work under this Annex will involve examining what key science gaps identified in the “State of Climate Change Science in the Great Lakes Basin” report can be addressed, as well as supporting the implementation of the other GLWQA issue annexes in order to ensure that climate change impacts are being taken into consideration in the overall implementation of the Agreement.
The work under this Annex to understand how climate change is affecting processes now, and may affect processes in the future, is important to making informed management decisions for the Great Lakes.
. Editor's Note: This article was updated on Dec. 14, 2016, to clarify information on air and surface water temperature increases.