Patrick Hamilton doesn't want to depress you on Earth Day weekend, but he does want you to rethink your impact on the planet.
As curator of the new "Future Earth" exhibit opening at the Science Museum of Minnesota, he hopes to raise awareness about the ways humans are dramatically changing our globe.
Humans are destroying habitats and entire species as we cover swaths of Earth's surface in crops, pastures and cities. A growing body of scientific evidence suggests we are shifting the chemistry of the oceans, changing the atmosphere and reshaping the weather.
"We are fundamentally altering the way the planet works, and we need to either get really good at managing that or live with the consequences," said Hamilton, the
Human activity now has such long-lasting and far-ranging consequences that geologists are debating whether to rename the current geological epoch the Anthropocene, the new age of man.
The term was coined a decade ago by Dutch chemist and Nobel Prize-winner Paul Crutzen, and the International Commission on Stratigraphy, the group that pinpoints the start and end of geologic periods such as the Pleistocene epoch, is exploring whether to formally adopt it.
"I think it's an appropriate term to be using," said Sarah Hobbie, a professor of ecology, evolution and behavior at the University of Minnesota and an exhibit consultant. "People have unique impacts on the globe that warrant calling this era something different."
The exhibit cannot explore all the ways humans are changing the planet, so it briefly introduces three biggies: agriculture, atmosphere and ocean acidification. Visitors also learn how researchers such as Hobbie are seeking solutions.
Humans have converted 40 percent of Earth's land surface, excluding the ice caps, to crops, pastures and cities. Crops alone account for an area the
"The only land left is rainforest and desert, and I'd like to keep the rainforest, please," said Tom Foley, director of the Institute on the Environment at the University of Minnesota where researchers are working on the question.
"I don't want to turn the Amazon into a soybean field."
Foley and others have laid out strategies for doubling food production on existing agricultural land, focusing on Eastern Europe, South America and Africa. Agriculture would need to become more efficient, he said. Farmers would need to explore new varieties, perhaps perennials rather than annuals, and Western diets would need to ease up on meat.
If Earth were a peach, its atmosphere would be the fuzz on the skin. And human activity is changing the fuzz.
"A lot of people have this notion that the atmosphere is so vast, so thick," said Hamilton, as he stood in front of the exhibit's wall-size mural of Earth, its atmosphere represented by a thin ring.
As we burn coal, petroleum and natural gas to fuel our lifestyles, we release carbon dioxide and other gases that hang in the atmosphere like an insulating blanket. Heat from the sun that would otherwise reflect off Earth's surface back into space instead remains trapped in the atmosphere and raises global temperatures.
While the exhibit doesn't dwell on climate change, Hamilton said the recent extreme weather in the Midwest, including higher average dew points during the summer, is consistent with climate scientists' predictions.
"We will see more," he said.
Besides affecting the atmosphere, carbon dioxide emissions are altering the oceans. About 30 percent of the gas in the air dissolves into seawater.
"In one way, it's good. It keeps it out of the atmosphere and stalls the effects of rising global temperatures," Hamilton said. The downside is it is making the oceans more acidic.
An interactive display lets visitors mimic the process by pumping carbon dioxide into a tank of water and watching a gauge register the drop in pH level. More acidic water threatens coral and
If humans are causing these global changes, the exhibit suggests we also have the power to manage them.
"We want people to realize that these problems have solutions," Hamilton said.
Have you noticed plumes of steam rising from buildings in winter? That's energy going to waste that could be redeployed.
One solution the exhibit highlights is a retrofit designed by Twin Cities mechanical engineer David Solberg for Faribault Foods bean cannery.
Solberg helps businesses around the world slash their electricity and fuel bills by capturing stray energy. His retrofit reduced the cannery's fuel consumption by 50 percent and its water use by 70 percent.
His proposal for heating the Science Museum of Minnesota would result in an 88 percent energy savings.
Like the museum's 2009 exhibit "Water," which encouraged visitors to think about how to sustainably manage global water supplies, "Future Earth" is designed to inform individual choices and public policy discussions.
"Yes, we're facing some really big challenges," said Foley, of the Institute on the Environment. "Yes, we're burning through a planet to live our lifestyle. But overall, the planet has never been better off. We know more about what's going on than ever before. We have more wealth and ability to change things than ever before. What we need to do is roll up our sleeves and get to work. I, for one, am not a doomsday environmentalist."
Maja Beckstrom can be reached at 651-228-5295.
IF YOU GO
What: "Future Earth" exhibit
When: Opens Saturday, April 21. Speakers from 11 a.m. to 1 p.m. include polar explorer Will Steger; Shawn Otto, author of "Fool Me Twice: Fighting the Assault on Science in America"; and Maggie Koerth-Baker, science editor at boingboing.net and author of "Before the Lights Go Out: Conquering the Energy Crisis Before It Conquers Us."
Where: Science Museum of Minnesota, 120 W. Kellogg Blvd., St. Paul
Cost: $10 to $13
Information: 651-221-9444 or smm.org.