By Travis Gulbrandson
More study is required to determine the exact nature of climate change, but solutions must be found to stem current warming trends, a recent visitor to the University of South Dakota said.
Dr. George Jacobson discussed these issues in his presentation, "Long-Term Climate Change Provides a Surprising Key to Understanding Our Environment," which he gave in Farber Hall on Sept. 6.
Jacobson is professor emeritus of biology, ecology and climate change at the University of Main, as well as past director of the Climate Change Institute.
"Studying climate in any one place doesn't really satisfy our need to understand the Earth's system," he said. "I think it's obvious, but if we're going to understand how the Earth's climate system functions, and how the oceans, atmosphere and biological systems are all active in the timing of the changes … we can't just have data from Maine or South Dakota."
For this reason, researchers collect sediment, ice and fossils from across the globe, each sample offering impact evidence from the past that allows for a more complete story.
"Our fundamental challenge is to understand the natural variability in the Earth's system – what kind of changes are happening in the Earth's climate, and what are the mechanisms of those changes?" Jacobson said.
This variability is a fundamental aspect of research, he said.
"Often we interpret what's happening in today's world with the changing chemistry of the atmosphere as a result of human activities, when we don't know what the natural variabilities could be," he said.
Jacobson pointed out that the Earth has gone through very warm periods which saw a much high rate of carbon dioxide in the atmosphere.
These periods ebbed, but now the trend seems to be returning. Jacobson said this is illustrated by the fact that the Arctic Ocean is freer of ice than is has been in "probably the last 10,000 years."
Not only is there less ice, the ice that remains is not as thick, which affects the climate.
"There no longer is a mechanism for producing the deep cold passes that come sliding down into northern Canada (and into the United States)," Jacobson said. "Even though the ice may develop in the ocean late in the winter … the ability of that area to produce these deep cold masses is drastically different."
He added that most of the arctic ice is only one meter thick, and nearly 80 percent of it is one year old.
"It's shocking how small an amount of ice there is and how fresh that ice is," he said.
As a result, Maine and other states are more likely to be 5-10 degrees warmer in all seasons, Jacobson said.
With the warmer temperatures, there is more concern for drought, as well as how various animal species and their migratory patterns are affected, he said.
Population also is a factor, being that the more people there are in the world, the more carbon their activities will generate.
"The higher amount of carbon in the atmosphere, the higher it stays for centuries," Jacobson said. "The residence time for carbon dioxide in the atmosphere is centuries."
This will only serve to keep temperatures higher, he said.
However, Jacobson said solutions can be achieved.
"When we think about sustainability and our ability to have a world that is safe for our children and grandchildren, we really have to come to grips with these issues," he said.
"There are going to be challenges, but we have a lot of smart people here and in other parts of the world who are trying to figure out how to do it.
"We can figure out a way to do a better job than we are now to deal with these issues," he said.
Jacobson cited the Clean Air Act as a positive example of how human behavior can affect the climate.
In the mid-1980s, there was much concern about acid rain and the number of factories producing sulphates that could lead to it, but between 1985 and 2010 the phenomena was almost entirely eliminated in this county, he said.
"It's pretty impressive," Jacobson said. "People said we couldn't do it … but now we wouldn't even consider going back."
Climate change needs to be approached in a similar way, he said.
"We can make decisions based on science that are effective and achieve some results," he said. "Now, changing the chemistry of the whole Earth's atmosphere from all over the world … is a real challenge.
"But humanity has this challenges, and I'm confident they will do what needs to be done," he said.