Ahead of his upcoming lecture, “As the Tide Rises: Decades of Watching Ice Sheets Change,” being held at the National Aquarium on November 2, we talked to Dr. Alley about his work and what continues to inspire the research that has taken him around the world.
What inspired your career as a glaciologist?
Initially, an accident. I wanted to major in geology, growing out of a childhood love of the outdoors, mountains and caves, rocks and minerals. But, I also wanted a summer job to make money to afford school, and to contribute to my education. I was fortunate that the professors at Ohio State helped me in finding one. Two jobs were open: one cleaning fossils with a dental pick, and the other “helping the glaciologist” (the late Ian Whillans). I opted for glaciology. It was so fascinating that I stayed with it. I started the summer of 1977, so that was 40 years ago.
What do the changes in ice sheets tell us about the overall changes on Earth?
We know with very high confidence that the world is warming, primarily because of human release of carbon dioxide from fossil-fuel burning. The support for that statement takes about 1,000 pages by the Intergovernmental Panel on Climate Change, and I do it in a semester in class. But, we do know that with high confidence.
One line of evidence that the world is warming is that we see shrinkage in all of the major classes of snow and ice where and when they are temperature-sensitive. The center of East Antarctica, which is colder than minus 40 degrees, is not likely to melt if you warm it by a degree or two. In really cold places, warming allows the air to carry more moisture and may give bigger snowstorms. But, if you look where and when the temperature matters, we see loss of seasonal snow, and seasonally frozen ground, permanently frozen ground, river ice, lake ice, sea ice, mountain glaciers and great ice sheets. There are exceptions, but looking at the big picture, there is shrinkage because of warming.
This shrinkage is causing many effects. Places such as parts of Asia and California have relied on winter snow as a reservoir, which melts slowly in the summer to release the water used by farmers and homeowners and salmon. Earlier snowmelt lowers this reservoir, and thus lowers streamflow when it is most important. I could go on with similar examples. The biggest one may be sea level rise, as ice from glaciers and ice sheet is turned into water that flows into the oceans.
What can we do to shift the Earth’s current trajectory when it comes to climate change and sea level rise?
We humans love the good we get from energy use, but we often dislike the unintended side effects. We suffered large problems when we burned trees and other fuel sources much faster than they grew back, creating scarcity and other issues. Fossil fuels provided new energy sources, but we are burning fossil fuels about a million times faster than nature saved them for us, and they simply will not grow back fast enough to be useful for millions of years.
Fortunately, we now know how to build a sustainable energy system that will power everyone almost forever. Getting there is a huge task, but the scholarship shows that we can do it in ways that help the economy as well as the environment, ethics, employment and national security.
Of the places you’ve spent most of your time as a researcher—Antarctica, Greenland and Alaska—which has had the most profound impact on you?
All of them together. We have a fantastic, diverse, beautiful world, that sustains us and so many other living things. When our hunter-gatherer ancestors spread around the world, they contributed to extinctions. In some sense, the planet was overpopulated, when the population may have been as small as a few million people. By learning to farm, we grew more food in less area, and allowed other species to thrive here with us. We again threatened biodiversity when we were burning trees and other fuel sources far faster than they grew back, but fossil fuels helped save them. Now, the climate change from fossil fuels and other impacts again cause threats, but we can learn to farm energy as we learned to farm food, making us and other living things better off.
As part of our Marjorie Lynn Bank lecture series, we invite you to come listen to Dr. Alley’s lecture on November 2, 2017! Tickets can be reserved here.