Climate change is a journey that we are all on for the rest of our lives. So let’s get right to the point: How will climate change impact the Great Lakes?

Warming temperatures, extreme weather and precipitation events and changes in growing seasons will impact the Great Lakes in many ways, notably:

1. Increase in invasive species;
2. Expansion of harmful algal blooms;
3. Fluctuation of water levels; 
4. Decline in coastal health.

Why do these matter? 

Some of these threats will be the subject of their own posts in the future. But a few connections for foundational understanding. 

As a fragile ecosystem, the Great Lakes have already been permanently damaged by invasive species. When non-native species are introduced by deliberate or accidental human activity, they often have no natural predators. Invasive species can decrease native fish or other species and degrade lake aesthetic value, threatening existing ecologies and economies. The zebra mussel infestation is one of the most prominent invasive species storylines of the Great Lakes. The mussels, which likely arrived in ballast waters or on ships from international seas, prolifically filter out algae that native species need for food, essentially sucking life out of the Great Lakes. They have created a dramatic upset in the ecosystem and, by reducing plant and animal life in the lakes, make them more prone to harmful algae. The mussels are also a physical nuisance, littering beaches, clogging pipes and even damaging boat motors.   

Harmful algal blooms upset the ecological balance of nutrients, plants and animals in and around the lakes. They can impact the respiratory health of animals and humans and they can threaten access to clean drinking water. The drinking water crisis in Toledo, Ohio in July 2014 raised awareness of this issue, but did not yield political or popular willpower to change human activity, notably in the agricultural sector, creating some of the challenge. 

Scientists see a future of significant water level variability due to climate change. High water levels and powerful waves and storms are causing coastal damage, including infrastructure damage along the shoreline and eroding beaches. A March 2020 analysis of rising Lake Michigan waters led the city of South Haven, Michigan to cite a cost of $16M to repair damage to infrastructure of the marina, stormwater pipes and utility lines and to make necessary improvements to their water filtration plant.

Low water levels due to greater evaporation as the climate warms put shipping, recreation and hydropower at risk and increases the possibility of harmful algal blooms, which thrive in shallower, warmer waters.   

Climate change also exacerbates existing water inequities.  Low-income communities and communities of color often bear the burden of environmental threats to the Great Lakes since they are often located in closer proximity to polluted waterways and access points and are more likely to have old and deteriorating infrastructure (e.g. lead water lines; older sewer pipes).

Our climate change journey will not have a happily ever after where everything turns out OK in the end. However, by better educating ourselves about impacts and potential mitigating activities, we can take personal and civic action to try and improve outcomes in our local communities, country and world.

I will continue to profile the impact of climate change on the Great Lakes region; it’s important that we honestly face and navigate the challenges. But I will also explore a connected, but distinct question: Will the Great Lakes region be a climate refuge? Stay tuned.