We’re the world champs. The Gulf of Maine, all the way from the north shore of Cape Cod to the top of the Bay of Fundy, is the fastest warming body of water in the entire world. On a map the gulf may look like an open bay but between Cape Cod and Nova Scotia the Gulf has a wall of banks, large underwater ridges that rise from the bottom of the ocean almost to the surface, that are pierced by 2 deepwater channels. These banks make our gulf a separate body of water, partially isolated from the Atlantic just as the many seas are. Only one other area in the world, a part of the northern Pacific Ocean, is warming faster. Some bodies of water like the Red Sea are hotter but they’re not warming is fast. We’re definitely number one, the fastest warming body of water in the world.
How come? Blame Greenland and her neighbors.
It’s a complicated story and there are 3 reasons for our warming. First, all of the oceans are warming. Well over 90% of the excess heat added to our planet is taken up by the oceans. Most is added to the surface waters, the top mile or so, but some of the heat warms water as deep as 2 miles.
Second are changes in the Gulf Stream current. That’s the large ocean current that runs north along the US’ eastern seaboard, bigger than 2000 Mississippi Rivers combined. It’s formed from hot tropical waters from both the North and South Atlantic Oceans. This is where Greenland and her neighbors enter the story. Their ice is melting so fast that there is a huge area of fresh cold meltwater in the middle of the Gulf’s path across the North Atlantic. A big problem. Hot Gulf Stream waters are backing up and pushing the normal colder Arctic waters around Newfoundland, Nova Scotia and the Gulf of Maine out of the way. So instead of the Gulf of Maine getting mostly Arctic waters from the coast of Labrador, we’re getting a lot more of the hotter Gulf Stream water. In 2018 there was hot water 400 feet deep off northern Nova Scotia. My daughter said that the swimming in Cape Breton was warmer than the swimming in Harpswell. I’ve never seen that.
Third, the story isn’t quite this simple. Surface ocean currents are driven by the prevailing wind currents which have similar paths. The warming of the entire Arctic has destabilized both the polar and the North Atlantic winds. These changes vary producing years or seasons with more backup, faster rising Gulf of Maine water temperatures and more sea-level rise. And then there are years with less backup. To what extent and how we’re just finding out. After all, in human history it’s never happened before. To quote Bob Dylan “the times they are a’changin”.
We’re at a critical time in human history. Recently 11,256 scientists warned that today we are “clearly and unequivocally … facing a climate emergency” that “is accelerating faster than most scientists expected”, “a catastrophic threat” to our planet if we continue with business as usual. However the UN reports that world governments are planning to use about 120% more fossil fuels by 2030 “than would be consistent with [limiting global] warming to 1.5°C”. Since 2017 energy from fossil fuel consumption has increased and that from renewables has decreased. In the next decade China alone plans to add new coal-fired power plants equivalent to the European Union’s entire power production. Many scientists think we are reaching or have already reached climate tipping points, thresholds once crossed that will have no return. Yet our country and the rest of the world continue to proceed with business as usual and the Gulf of Maine’s water temperature continues to rise.
Bruce MacDougal teaches climate science at Midcoast Senior College and is talking about climate change and the Global Order, the next 30 years, in MSC’s February Winter Wisdom program.
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