While ice cover across the Great Lakes – a network of five freshwater lakes about the size of the United Kingdom – has been declining since the early 1970s, this year it’s likely to reach an unprecedented low.
By mid-February, ice cover historically averages about 40%. This year it was about 4%. Even before the official end of winter on 19 March, three normally frigid cities – Grand Forks, North Dakota; Milwaukee, Wisconsin; and Minneapolis-St Paul, Minnesota – have already recorded their warmest winter on record this year. Scientists say warming temperatures are a result of human-made climate change and are expected to continue rising for decades to come.
This winter’s mild temperatures have played havoc across the midwest, wrecking plans and disrupting local economies.
A report published in January found that the number of -35˚F (-37.2˚C) readings in northern Minnesota have fallen by up to 90%. Low temperatures play a key role in weed and pest control.