By Janice Cantieri

“You can’t open a McDonald’s ketchup packet without the little notch. Try it, okay?” noted climatologist Richard Alley.

Without the little notches, plastic ketchup packets are almost impossible to open no matter how much you pull or tear. Cracks in the world’s ice sheets are like those little notches, Alley said. Once these cracks appear in ice sheets, the stress concentrates there and eventually can lead to large sections of ice falling off and melting quickly.

Alley, professor of geosciences at Pennsylvania State University, used the analogy to describe how ice sheets can rapidly break apart due to preexisting “cracks” or “notches” in the ice produced when meltwater opens small crevices and then makes them big ones, he said. “When you make these cracks bigger, it makes [the ice sheet] break way faster,” Alley said at this year’s Comer Abrupt Climate Change Conference.

Alley and a gathering of the world’s top geologists, paleoclimatologists, engineers and climate modelers meet each fall in southwestern Wisconsin to discuss their most recent discoveries on the origins and consequences of abrupt climate change.

“We know what nature can do, so we know that climate change is a big deal, and we know that what humans are doing now is not natural,” Alley said. “Across almost anything that we look at, the first degree of warming had very small costs, but we’ve done that. The second degree of warming will have larger costs. We’re mostly committed to that. The third degree of warming will have even larger costs.”

Alley emphasized the fact that the Pentagon prioritizes climate change as a national security issue, and that adapting to a sustainable energy system is beneficial for the economy.

The key question the scientists addressed at this year’s conference was urgent – “not whether or not global warming and climate change is happening, but how fast,” said Philip Conkling, a sustainability consultant and author. “To understand that, we have to understand the dynamics of the past.”

Field research took many of the scientists around the world and deep into the history of Earth’s climate in order to better understand the sensitivities and “switches” that triggered abrupt changes thousands and even millions of years ago. Piecing together these discoveries provides a progression of natural events to compare to the changes occurring today at an accelerating rate as a result of human impacts.

Joerg Schaefer, a geochemist at Columbia University, presented the latest findings on the threat to the stability of the melting  Greenland ice sheet, which holds an equivalent of about 7 meters of sea level rise (about 23 feet), enough to inundate many coastal cities.

“The Greenland Ice Sheet was most certainly gone during natural forcing [in the past] and of course this is also worrisome because what we are doing in the moment will almost certainly at one point, and maybe soon, deglaciate Greenland. So it’s really pressing that we understand these processes quickly,” Schaefer said.

The problem is that human use of fossil fuels is moving global climate much faster than nature does, several scientists said.

In order to avoid significant sea level rise, droughts, food shortages, disease, and international conflicts, the world must cut carbon dioxide emissions by more than a factor of 10, said pioneering climate scientist Wallace Broecker of Columbia University.

“Every ounce of CO₂ we put in the atmosphere makes it a little bit worse. We see things happening already and obviously. As we warm the planet up more those things are going to get bigger and extend further,” he said. “We’ll start to see whether sea level will start to rise at a bad pace. It’s going to move ecology everywhere.”

Levels of carbon dioxide in the atmosphere remained below 300 parts per million (ppm) for at least 800,000 years prior to the Industrial Revolution, even during the warm spells between the ice ages. Carbon dioxide levels are now rising above 400 ppm as the greenhouse gas traps heat and is rapidly warming the planet.

“The biggest hope is to get rid of using fossil fuels, but, you know, I can’t see that happening in less than 50 years,” he said. And because of the role of the ocean in absorbing CO₂, there is a high chance that the world is already committed to significant temperature rise, likely well above the 2 degrees Celsius cap (3.6 degrees Fahrenheit) set out in the 2015 Paris Agreement, Broecker said.

While many researchers painted a bleak future for the planet if no action is taken now, some promising innovations could provide solutions, or at least prevent some of the worst damages caused by warming. Physicist and engineer Klaus Lackner is developing a technology to capture carbon dioxide directly from the air. It could help “close the loop” of carbon emissions, he said at the conference.

A prototype of Lackner’s “artificial tree” is successfully operating on the roof at Arizona State University’s Center for Negative Carbon Emissions for the past year. One hundred million of the units, each built to remove one metric ton (2,204 pounds) of CO₂ a day, could offset the 36 billion metric tons of carbon dioxide emitted by human communities each year, he said.

Meanwhile, the global research continues. A team of researchers and graduate students led by climatologist Aaron Putnam from the University of Maine presented on field work in the remote Potanin Glacier Valley in Mongolia’s Altai Mountains. During the six-week expedition, the team trekked through the mountains and collected boulder samples that map the retreat of the glaciers, revealing clues about why, when, and how quickly the last ice age ended.

Kevin Stark of the Medill News Service presented drone footage and photos from his experience as an embedded reporter with Putnam’s team in Mongolia, and his story was published in Pacific Standard Magazine in October.

The conference closed with warm memories of the late Gary Comer, who created the Comer Family Foundation to support initiatives in healthcare, education and the environment. Comer, the founder of the Lands’ End retail company and a Chicago native, became concerned about warming global temperatures after completing a 2001 sailing expedition through the Northwest Passage, an Arctic passage connecting the Atlantic and Pacific Oceans. Warming temperatures had melted many of the icebergs in the famed shipwreck alley of the passage and created a clear pathway for his yacht.

Upon his return, Comer sought out Broecker, credited with coining the term “global warming” in 1975. Together with Alley and glaciologist George Denton, of the University of Maine, they created a fellowship program to support research on the causes and consequences of abrupt climate change. Since 2003, more than 300 papers have been published by Comer Fellows in peer-reviewed journals.

Philip Conkling closed the conference by reading a note he wrote for Gary Comer in 2005, after one of their final sailing expeditions together:

To be brave and cheerful – to be brave and cheerful is no easy thing. Staring in the face in the morning’s mirror, where the skin fits more loosely now. Like a favorite sweater, gone soft with age. Surely, the news cannot be all bad. The images the eyes dissolve are no longer cut with the sharpest knife, but we have already seen much of the world. And anyway, what we need now is vision, not sight. Inner vision too, and insight, if it’s not too much to ask. To be brave and cheerful is no easy thing. Be calm, and live with light in a slowly freezing sea. Should it be surprising that those who have given so much find it hard to drink from an overflowing cup? August 12, 2005.