The Environment Report
4:11 pm
Tue January 22, 2013

New report assesses current and future climate change

You can listen to today's Environment Report here or read an expanded version of the National Climate Assessment story below.

You probably remember that extreme weather was not kind to Michigan crops last year.

Frank Szollosi is with the National Wildlife Federation.

“We lost more than 80 percent of our apples and peaches, we lost grapes and cherries. Our cherry farmers saw 90 percent of its crop destroyed because of the unusually warm winter last year followed by hard freezes,” he says.

The federal government has put out a new draft report on how our climate is changing. More than 240 scientists wrote the report.  It’s called the National Climate Assessment.

Agriculture is one of the key messages of their chapter on the Midwest.

Don Scavia is a lead author of the Midwest chapter. He’s the director of the Graham Sustainability Institute at the University of Michigan. The report says in the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops.

“That could initially be good for agriculture. But then you have to think about what’s happening with precipitation. We’re getting more and more extreme rainfall events and floods in the spring, coupled with a longer, drier summer. So that increase in the frequency of storms and heat waves could actually end up being bad for agriculture,” Scavia says.

He says the agricultural community will also need to find ways to deal with the potential for warmer springs with sudden cold snaps.

Melting ice

The report also notes that ice cover on the Great Lakes has been going down since the 1970's, especially for lakes Superior, Michigan, Huron, and Ontario.  

Don Scavia says less ice could mean a longer shipping season. But it could also mean more lake effect snow.

“Because there will be more evaporation off of the Lakes, so initially that increased water vapor will end up as larger snow events and lake effect snow events, but as temperatures warm, they’ll probably turn into rain events,” he explains.

Six take-home messages

The Midwest chapter outlines these six key messages:

  1. In the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops, though those benefits will be increasingly offset by the occurrence of extreme events such as heat waves, droughts, and floods. In the long term, combined stresses associated with climate change are expected to decrease agricultural productivity, especially without significant advances in genetic and agronomic technology.
  2. The composition of the region’s forests is expected to change as rising temperatures drive habitats for many tree species northward. The region’s role as a net absorber of carbon is at risk from disruptions to forest ecosystems, in part due to climate change.
  3. Increased heat wave intensity and frequency, degraded air quality, and reduced water quality will increase public health risks.
  4. The Midwest has a highly energy-intensive economy with per capita emissions of greenhouse gases more than 20% higher than the national average. The region also has a large, and increasingly utilized, potential to reduce emissions that cause climate change.
  5. Extreme rainfall events and flooding have increased during the last century, and these trends are expected to continue, causing erosion, declining water quality, and negative impacts on transportation, agriculture, human health, and infrastructure.
  6. Climate change will exacerbate a range of risks to the Great Lakes region, including changes in the range and distribution of important commercial and recreational fish species, increased invasive species, declining beach health, and harmful blooms of algae. Declines in ice cover will continue to lengthen the commercial navigation season.

Learning to adapt

This is the third National Climate Assessment. Don Scavia notes that for the first time, it includes a chapter on ways we might be able to adapt to a warming climate.

“Much of the focus is rightly placed on mitigation – on what the countries need to do around the globe to reduce emissions, so we can stop this progression of moving towards a warmer climate, but we have to start helping people adapt, because no matter what we do at this point, the climate is already changing and it’s going to continue to change,” he says.

He says that means, for example, looking at the infrastructure in our cities and making sure we can deal with heavier storms, and protecting people who are at risk from increased heat waves.

The report is open for public comment.