Did you know that since the dawn of agriculture, almost one third of the soil capable of supporting farming worldwide has been lost to erosion? Did you know that Antarctica doubles in area when the surrounding southern ocean freezes each winter? Did you know that the doubling of Earth's population, a process that once required thousands of years, now takes place in less than fifty? Do you know ... how these facts relate?
Last Wednesday, I had the opportunity to attend an engaging talk by Dr. Henry Pollack
, professor of geophysics (emeritus) in the Department of Geology at the University of Michigan, about his most recent publication, a book called A World Without Ice
. As the title suggests, the book is about the relationship between ice and people. Pollack surveys the pivotal function ice has had throughout Earth's history, including the development of the Earth's climate and landscape, and the corresponding impact that people have had on ice — something the website
calls "a delicate geobalance."
At the talk, Pollack explained that the time frame for the book spans from when humans were small players, reacting and adapting to their environment, to today's epoch, where as nearly seven billion humans currently occupy the Earth, we have become "the strongest geological agent on the planet." We move more dirt than rivers, we continue to send more chemicals to the ocean, we change the composition of the atmosphere at previously unobserved rates. Therefore, the partnership between ice and people is more precarious today than it has ever been — and is worth serious consideration.
So why ice as the vehicle to tell the story of climate change? Dr. Pollack
, who served as science advisor to former Vice President Al Gore's Climate Project, said ice is "a very good prism through which to see the story of climate change." In the climate system, ice is a major player. It has an extremely high albedo, meaning that the white color makes it very reflective of solar radiation. The global distribution of the sun's heat is dependent on the interaction between ice and other things on Earth that are not as reflective. Consider the Arctic Ocean. Each summer, a greater area of dark, open ocean is exposed. Instead of reflecting solar radiation, the ocean is absorbing it, causing the ocean to heat and expand. Because our climate is so sensitive, when the temperature changes only slightly, the feedback is tremendous, and large areas of ice melt and disappear. We can observe these climate changes through the global distribution of ice.
The second reason Dr. Pollack chose ice: the consequences of changing ice on Earth affect people very dramatically each year. The first ice that we are losing is mountain glaciers, of which he says few will survive this century. The mountain top ice and winter time snow that is continuously falling in shorter intervals provides the water for agriculture for about a third of Earth's population. Further, there is the media and Hollywood's apocalyptic harbinger, sea level rise. Fear-inducing scenarios aside, it is directly, relevantly related to ice and climate change. As sea water gets warmer, it thermally expands and occupies more volume. Pollack gave "substantial probability" that by the end of the century, the sea level will be a meter higher, and possibly two meters, depending on how humans mitigate and arrest the situation. The Earth's densely populated coasts will have to answer to these decisions.
Finally, Dr. Pollack chose ice as his medium because it is "apolitical." At this point, he read a quote from the book: "Ice asks no questions, presents no arguments, reads no newspapers, listens to no debates. It is not burdened by ideology and carries no political baggage as it changes from solid to liquid. It just melts."
He went on to point out two conclusions from the IPCC's last report in 2007. First, climate change is unequivocal. We do not need to argue about it anymore. Second, most of the observed increase in global average temperature since the middle of last century is very likely due to human activity, with about a 90 percent probability. I appreciated the analogy that followed: if you went to a casino and they told you that your chances of winning were 9 out of 10, you would take them. Therefore, the IPCC is making very strong scientific statements. Yet, only about half of America believes that climate change is real, let alone that humans are playing a role.
Pollack was particularly receptive to the difficulty in grasping our own role. The cause and effect between leaving the thermostat on high, for example, and ice melting in the Arctic is separated by such a large space and time that it is difficult to imagine that we have agency. Moreover, "the biggest barrier to the acceptance of anthropogenic climate change is a social barrier," said Pollack. The issue has been removed from the realm of science into the realm of political discussion, and as bipartisan politics typically operate in America, if you do not like the messenger, you do not listen to the message.
Dr. Pollack wrapped up his talk by acknowledging an important distinction. There are uncertainties with social science. We do not know the number of people that will be living on Earth by the end of the century, for instance. But there are no uncertainties with climate science.
In the spirit of Earth Day, let us remind ourselves that we have the power to intercede with the momentum of the changing climate. As individuals, it might seem that our influence is negligible. But we cannot continue to deny our collective power. After all, we are the strongest geological agent on the planet.
Dr. Pollack's book A World Without Ice
is available through Amazon, Barnes & Noble, Borders, Indiebound and Penguin. You may contact the author at firstname.lastname@example.org