Climate change will change us

Dr. Meghann Jarchow, assistant professor of sustainability, speaks about the challenges facing agriculture because of climate change during Monday’s international forum at the University of South Dakota in Vermillion.

 (Kelly Hertz/Yankton Press & Dakotan)

By Randy Dockendorf

randy.dockendorf@yankton.net

At Monday's forum, University of South Dakota panelists found global warming to be a very hot topic.

"Global Warming: The Evidence Is In!" covered the scientific data pointing to global warming. But the panelists also acknowledged the political, social, economic and religious issues.

Climate change will directly affect agriculture and the way an exploding world population is fed, according to Dr. Meghann Jarchow, assistant professor of Sustainability in the Department of Biology.

The future points to intense, less frequent precipitation; and wetter winters and springs, along with drier summers, Jarchow said.

"We are seeing more events like 3 inches (of precipitation) followed by long periods of no rain, compared to spread-out rainfalls. That requires much adjustment," she said.

During the past four decades, temperatures have cooled during the day and have risen at night, Jarchow said. The Midwest has seen dramatic swings in climate patterns in recent years, she added.

Looking to the future, southeast South Dakota is projected to see its winter temperatures rise around 7 degrees by the end of the century, while summer readings are projected to rise about 5 degrees.

Jarchow showed a crop map of Clay County consisting almost exclusively of corn and soybeans. In the future, farmers will need to produce a wider, more diverse range of crops, she said.

The current farm system and government policies focus on highly productive, specialized crops, Jarchow said. "It requires intensive, carefully-timed management," she said.

She recommended a wider range of crops to reduce risks; government policies supporting diversification while continuing to provide risk protection such as crop insurance; and focusing on perennial crops. Future practices and policies also need to take into account carbon sequestration, along with water regulation and purification, she said.

The future is now in much of Africa, which is suffering from a lack of water and other problems created by global warming, said Dr. Moses Ikiugu of the School of Health Sciences.

He visited Kenya for a month, with no water supply at the house where he was staying. "The big chore was finding water, because it was not being replenished," he said.

The problem is not limited to Africa, he said, noting water shortages around the globe including the United States. Drought and other climate changes have contributed to problems including heart disease, water and food-borne illnesses, respiratory and skin diseases, West Nile Virus and increased infections, he said.

Global warming is accepted by most scientists, according to the third panelist, Dr. Mark Sweeney of the Earth Sciences Department.

"These days, most people agree that the Earth is warming," he said. "Scientific consensus is that humans play the primary role in this; those that disagree hide behind the often repeated mantra 'The climate has always changed naturally.' But one must understand what causes the climate to change naturally before making blanket statements that are not supported by data."

Sweeney noted this year's scientific milestones related to global warming.

The Arctic Sea ice is breaking the record for minimum extent, based on about 30 years of satellite data.

In addition, carbon dioxide is at its highest level, hitting 395 parts per million (ppm) this year, Sweeney said. Carbon dioxide increases by about 2 ppm per year, so it will break the 400 ppm mark in two to three years. Surpassing that mark would signal a new threshold for the dramatic global warming that has continued for the last two decades, he said.

"Climate scientists claim that, to restore Earth's energy balance, (carbon dioxide) emissions must not exceed 350 ppm per year," he said.

While politicians may ignore the issue, global warming continues, Sweeney said. "As carbon dioxide and other greenhouse gases increase, it's like steroids for the climate," he said.

Jarchow believes changing the conversation may create an atmosphere for finding solutions.

"If we talk about the effects as they are now, and the things we see, it's not as political," she said. "It's something we need to do now, and it won't be as polarizing."


Retired USD economics professor Benno Wymar moderated the event, sponsored by the USD Beacom School of Business. For more information on the international forums, email Benno.Wymar@usd.edu.

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