One of the bonus amenities on an Antarctic cruise I took recently with Abercrombie & Kent was the enrichment lectures, which helped me to understand the birds, whales, seals, ice and rocks we were seeing at the bottom of the Earth.
One that stuck with me was Reed Sherer's talk on climate change, entitled "Paleoclimates: Is What's Past Prologue?"
Even though Scherer's topic was among the least warm and fuzzy of the cruise -- no cute penguins or sleek seals -- I'd say about half of the 165 passengers on the ship attended.
Scherer is a professor of micropaleontology and biostratigraphy at Northern Illinois University, and some of his research projects focuses on climate change, the Antarctic ice sheet and fossil diatoms.
He's spent time in the continent's interior, melting and drilling through thick ice to take core samples of air frozen in ice hundreds of thousands of years ago. Like the rest of the A&K expedition team, Sherer excelled at making his expertise understandable to lay passengers.
He explained how air bubbles trapped after snowfalls in Antarctica up to 800,000 years go show much lower levels of the greenhouse gas carbon dioxide in the atmosphere. It was easy to relate to photo slides Sherer showed of his research team taking samples, because we were right there in the snow and ice, too.
In a chart, Scherer showed the dramatic measured increase in atmospheric CO2 since the dawn of the industrial age.
His message, drawn from Shakespeare's "The Tempest," is that while "the past is prologue" when it comes to climate change, "what to come [is] in yours and my discharge."
In other words, the past may be set, but the future is up to us.
Scherer said he tends to agree with climatologists who say that it is probably too late to prevent the two major ice shelves in west Antarctica from melting away, but he said that human action could still slow the rate of melt and forestall the effects for decades.
I asked Sherer about another pollution problem that first manifested itself in Antarctica: the hole in the ozone layer that shields humans from the most harmful ultraviolet radiation from space.
Caused by refrigerants, aerosols and other products that used chlorofluorocarbon gases (CFCs), the hole in the ozone in Antarctica was viewed with alarm when first discovered in the 1980s but has been closing steadily and at the current pace should disappear in the 2070s.
Was the success in combating ozone depletion a model for addressing climate change?
Scherer said the biggest difference between then and now was the respect accorded scientific opinion. Discovery of the hole led in short order to the 1987 Montreal Protocol, an international agreement banning CFCs.
Progress on climate change at conferences in Kyoto and Paris has been halting at best. Sherer said the public and politicians no longer defer to scientists the way they did in the 1980s, making agreements on climate change harder to reach.