Climate Column: Thoughts after Sea Change voyage
An elderly man raised his hand. "What do you know about the temperature of the lake?" he asked. "My memory is that it was always around 4 degrees C (38-40 degrees F)." We were sitting in a school library with a couple of dozen high schoolers, their teachers, the superintendent and other adults who were intrigued enough to listen to our presentation of "Climate Change on Lake Superior." His question was the perfect introduction to our next slide, in which Mark describes our "a-ha" climate moment.
Sailing along in offshore waters in 2010, the temperature 4 feet under the surface was 75 degrees Fahrenheit. In response, we all went swimming. "Don't forget this because it will never happen again," Mark predicted blithely, his climate radar still very low. He knew that historically, the lake temperature tops out around 59 degrees Fahrenheit in August or September — still too cold to swim in, though quick dips are possible at that temperature. The next three summers, he discovered, temperatures moved into the 70s every summer.
We take people sailing most days in July and August, and try to prepare people for sailing on Lake Superior. For our two hour sails, we start the season cautioning our guests, "Wear long underwear and a stocking cap." In recent years, as early as July, we've changed our tune to, "Bring a bathing suit just in case there's no wind." Sometimes it's hard to believe that things can change that quickly — and indeed, the summer of 2014 (after that terrific winter), the water did not get as warm. But by 2015, in the midst of a year of record global warmth, the temperatures actually reached 80 degrees near the south shore. We heard this from a fisherman who was trying to make sense of the fact that there were no fish to be caught that season.
Yes, Lake Superior is warming quickly; it is in fact one of the fastest-warming large, cold lakes on the planet. We know this because Zander, one of our crew, did some research and learned that NASA has studied 250 large lakes around the world and came to this conclusion about Lake Superior. Why is it warming so quickly? The ice cover provides a partial explanation. Lake Superior traditionally freezes over, at least a good chunk, for months of every winter. "It was white every year — you could count on it," an old-timer from Knife River told us. For Lake Superior, a few degrees of warming can mean the difference between ice and no ice, as it clearly has in recent winters. When there is no ice, water absorbs heat from the sun all winter rather than reflecting it back off the ice and into the atmosphere. All winter, the lake misses its customary ice-covered cooling, and in the spring is warmer than usual. This increases the chances that the lake cover will be sparse the following year. This is our current pattern, and it will continue to accelerate unless other forces override it.
This is the message we gave to 600 to 700 Canadians along the North Shore this spring, and the message that we continue to share with anyone who will listen. The story has no ending, and no one knows the future. How quickly we as a global community move to renewable energy in the next few years and decades will determine whether the Lake Superior our children know bears much resemblance to the lake as it was 50 years ago.
What is your role in this? This is a question no one can answer for anyone else. The Ojibway people of the Pic River First Nation, just south of Marathon in the far northern reaches of the lake, are taking an inspiring number of steps, even with their minimal resources. They are building a new school with geo-thermal heating; they are investing in a community solar garden, and they are building south-facing homes so that when they can afford the solar panels, they can be installed on the roofs. It isn't about funding, it's about making intentional decisions about what can be done, and then taking action. We will be returning to Two Harbors this summer full of awareness of what needs to be done and inspired by examples of what is being done elsewhere.
Katya Gordon of Two Harbors is a member of the Duluth/North Shore chapter of the Citizens Climate Lobby. She writes a regular column on climate change for the News-Chronicle.