Gretchen Whitmer vows action on climate. Here’s how warming hurts Michigan.

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New Michigan Gov. Gretchen Whitmer is vowing to move aggressively on climate change, calling it a “a real threat to our environment, our economy, and the health and wellbeing of the people of our state.”

Sworn in last week, the Democrat vowed during last fall’s campaign to enter Michigan into the U.S. Climate Alliance, a group of 17 governors committed to reducing greenhouse gas emissions and create an office of climate change.

The vows come as independent scientific studies continue to conclude earth’s atmosphere and oceans are steadily warming because of human activity that emits carbon dioxide.

In October, the U.N. Intergovernmental Panel on Climate Change — comprised of the world’s top scientists — warned the planet will warm 2.7 degrees Fahrenheit by 2040 or sooner unless global leaders pursue “unprecedented” changes.

Without dramatic decreases in greenhouse gas emissions, severe drought and coastal flooding could displace millions of people in low-lying areas, disrupt global food supplies and destabilize some governments, the report warned.

What’s it mean for Michigan, whose 83 counties have all grown hotter on average over the past three decades?

In November, the National Climate Assessment, a landmark federal government report, examined climate change’s effects by region. Here are six takeaways from the report about the Midwest (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio and Wisconsin):

A blow to farming

“Projected changes in precipitation, coupled with rising extreme temperatures before mid-century, will reduce Midwest agricultural productivity to levels of the 1980s without major technological advances,” the report said.

That’s bad news for agribusiness, which includes 51,000 farms covering 10 million acres statewide. The Michigan food and agriculture industry employs nearly 1 million workers and contributes $101 billion to the economy, according to state estimates.

So far, warming has extended growing seasons and bolstered production of crops in some parts of the Midwest. But warming also will bring more rainfall that worsens soil erosion and improves breeding conditions for crop-damaging pests, the report warned.

Those trends are troublesome for growers of soybeans and corn, which are grown on 75 percent of the Midwest’s farmable land and are among Michigan’s top crop exports.

Michigan produced $1.1 billion in corn grain in 2016, and $983 million in soybeans.

Trees are in trouble

Climate change is threatening the Midwest’s 91 million acres of forests, which contribute $122 billion to the economy and are vital to everyone from hunters to tribes.

More frequent drought late in growing seasons is expected to kill younger trees, while warmer winters will reduce snowpack that insulates soil, leading to more frost that damages tree roots.

“Many tree species on which tribes depend for their culture and livelihoods—such as paper birch, northern white cedar, and quaking aspen—are highly vulnerable due to temperature increases,” the report said.

Forests cover more than half of Michigan lands, according to the U.S. Forest Service, and associated industries employ nearly 100,000 workers.

In 2016, 22 invasive plant species were identified in Michigan forests. Ash and beech trees have increasingly died off in recent years — largely due to a pest called the emerald ash borer and beech bark disease.

More species could go extinct

Development has already harmed species across the Midwest’s prairies, wetlands, forests and freshwater ecosystems. Warming temperatures and drought will “accelerate the rate of species declines and extinctions,” the report said.

The dire outlook extends to the Great Lakes, the world’s biggest freshwater ecosystem, which can expect rising temperatures, higher summer evaporation rates, more pollution from runoff and more harmful algal blooms.

The species loss would harm “flood control, water purification, and crop pollination, reducing the potential for society to successfully adapt to ongoing changes,” the report said.

Public health worries

Rising temperatures will worsen air quality, increase pollen, bring heavier rains and more threats from disease-carrying pests, the report warns.

Climate change could increase the prevalence of meteorological conditions that make pollutants like ozone dangerous. By 2050, researchers expect ozone concentrations to kill 220 to 500 Midwesterners each year.

“By mid-century, the region is projected to experience substantial, yet avoidable, loss of life, worsened health conditions, and economic impacts estimated in the billions of dollars as a result of these changes,” the report said.

“Improved basic health services and increased public health measures—including surveillance and monitoring—can prevent or reduce these impacts.”

In Michigan, rising temperatures could reverse decades of improvement. State reports show that monitoring sites in southeast Michigan – the most industrial area in the state –  have detected far less pollution since monitoring began in 1978.

Infrastructure threats

Heavier flooding and more heat will damage stormwater systems and other infrastructure — including roadways and bridges.

“The annual cost of adapting urban stormwater systems to more frequent and severe storms is projected to exceed $500 million for the Midwest by the end of the century,” the report said.

High heat stresses pavement, bridge expansion joints and railroad tracks.

“The EPA estimates that higher temperatures associated with unmitigated climate change would result in approximately $6 billion annually in added road maintenance costs and over $1 billion in impacts to rail transportation by 2090,” the report said.

That’s an area where Michigan is lagging. The state needs to find an extra $4 billion each year to keep roads, bridges, water and sewer systems from crumbling, according to a 2016 report from a commission assembled by Gov. Rick Snyder.

And Whitmer’s chief promise in her campaign was to “fix the damn roads,” which could lead to higher taxes or user fees.

Community action

Communities can take action — through studies and planning — to understand how to serve those who are most vulnerable to climate change, including the poor and elderly, the report noted.

“Documented implementation of climate change planning and action in Midwest cities and rural communities remains low,”

Since 2011, 13 Michigan communities have adopted plans to dramatically reduce greenhouse emissions or increase their use of renewable energy, according to the Michigan Climate Action Network.

Ann Arbor, Grand Rapids, Traverse City and Meridian Township in Ingham County, for instance, plan to increase use of renewables to 100 percent within 20 years, while Detroit’s plan calls for dramatic increases in recycling, among other reforms.