Geologist uses mud to clarify Arctic warming

by Eric P. Skalac
Nov 04, 2010

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Yarrow Axford

Northwestern University's Yarrow Axford in the Arctic, where she studies of mud to show that the region is warming.

The Arctic is warming, and that’s not a good thing.

Yarrow Axford, a geologist at Northwestern University, is studying the temperature history of the Arctic using tools that may seem strange to us: the mud from beneath Arctic lakes, and the remains of non-biting midges contained within.

When Axford was a college freshman at Mount Holyoke College in the 1990s, she’d thought of science as a matter of “just about memorizing facts and equations,” though she soon realized just how many unanswered questions and topics of fresh investigation remained.

After an introductory geology class, Axford became enchanted by the way that earth science could explain the world around her. “There’s a reason there are mountains in certain places and not in other places. There are reasons it rains or doesn’t rain. Just the fact that there were actual explanations for all of that was really exciting.”

Now, Axford mostly researches the last 100,000 years—really recent stuff in geologic terms. Primarily, she studies climate processes and climate change in the Arctic, but also the role that the Arctic plays in the global climate system.

“She integrates biological data with geochemical data, which is a really powerful combination,” said Brad Sageman, chair of the Department of Earth and Planetary Sciences at Northwestern, and an enthusiast about Axford’s current work:  

Axford’s been very productive for a young scientist, Sageman said. “She’s been going gangbusters in the last two years… she’s really exploding out of the gate here.”

Axford  said that her research focuses on the question, “How unusual are the dramatic changes that we’ve seen in the Arctic recently?’”

It is in fact quite unusual, as Axford told the audience at this year’s Climate Change Symposium, co-sponsored by Northwestern’s Earth and Planetary Science Department, the Environmental Science and Engineering Program, the Environmental Policy and Culture Program, and the Initiative for Sustainability and Energy at Northwestern (ISEN).

“You hear that argument made a lot,” Axford said after the symposium, referring to climate change skeptics and their insistence that current climate warming is the result of natural variations in the climate system. “Well, we can test that idea by going back and looking at long-term records of natural variation, and asking those records if what’s happening now fits into natural variation that we’ve seen in the past.”

She teaches a graduate course on sustainable energy and climate change for ISEN and she demonstrates the factual evidence for human-driven climate change.

“What I try to establish pretty firmly," she said, "is an appreciation for the fact—and it’s a fact—that if you add a lot of carbon dioxide, or any greenhouse gas to the atmosphere, you’ll change Earth’s energy balance, and you’ll warm the planet.” 

But simple facts are often muddled by the reality of a very complicated science.

“That simple fact gets very clouded in all the details of climate feedbacks: of clouds that we don’t understand very well, the fact that we don’t know exactly how sensitive climate is to a given amount of greenhouse gas.”

Axford said that it often comes down to trust. “Most people are either predisposed to trust me on the issue or not trust me on the issue. That’s a very simple case, but kind of hard to make if someone’s not predisposed to trust me—I have to show them all the facts, and that takes a while.”

But she said she likes to start with the simple facts of climate change, because complicated questions follow. “How fast are we going to warm, how much should we worry about it, should we care, is it immoral to do nothing about it, what can we do, how much is it going to cost? Those are all really hard questions to answer, so I like to start with the easy part, which is yes, we’re warming the planet."