While the Earth’s climate has been changing throughout history, most of the current warming trend has a greater than 95 percent probability to be the result of human activity since the mid-20th century, according to NASA’s Global Climate Change website.
This global warming trend is proceeding at a rate that is unprecedented over decades to millennia, the website states. Scientists attribute it to the human expansion of the greenhouse effect caused by certain gases in the atmosphere — water vapor, carbon dioxide, methane, nitrous oxide and chlorofluorocarbons — that block heat from escaping.
It states climate change has already had observable effects on the environment — glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.
According to the fourth National Climate Assessment Report published by the U.S. Global Change Research Program, the Midwest will not be exempt from the effects of climate change.
Extreme heat, heavy downpours and flooding will affect infrastructure, health, agriculture, forestry, transportation, air and water quality and more, the report states. Climate change will also exacerbate a range of risks to the Great Lakes.
Here’s a look at some statistics that show the effects of climate change over the past few decades: