The Documentary Film & Discussion Series Explores the Science of Climate Change, May 10 and 22
The Documentary Film & Discussion Series will present two films in May, Climate Change: Examining the Evidence and Climate Change Models: Predictions and Uncertainty. Films are scheduled for 7:00-9:00 pm in the Ashland Public Library Community Room, 66 Front Street, Ashland, MA. Admission is free. Viewers are invited to stay for discussion. All points of view are welcome. The documentary film series is sponsored by the Friends of the Ashland Library.
Special guests Christine Fletcher, Ashland High School biology, marine biology and environmental science teacher, and Leah Marshquist of Transition Ashland, an effort to strengthen local economy and community, will be on hand to help lead the discussion.
Thursday May 10, Climate Change: Examining the Evidence (56 min)
This documentary presents and examines evidence of human induced climate change from the burning of fossil fuels. The 21st Century has been marked by record-setting increases in global average temperature. Small increases in global average temperature have consequences on ecosystems and species. The film examines impacts on forests, oceans, the Artic, Greenland Ice Sheet and permafrost.
In the Southwest, 40 to 80 percent of pinyon pine forests died between 2002 and 2003. The massive dieback was caused by high heat accompanying drought that began in 1996. Droughts in the region are not new. What is new is the higher temperature that pushed pinyon and other vegetation beyond its tolerance point. In addition, mountain pine beetles, surviving in larger numbers because of milder winters, have destroyed lodgepole pine in the Pacific Northwest and have jumped to the jack pine, potentially endangering forests from British Columbia to the east coast, including Canada’s climate-regulating boreal forests.
Warming ocean temperatures threaten coral reefs and the zooanthellae algae they depend upon for nourishment. It is a familiar pattern: new temperature extremes push dominant species into weakened condition and then disease finishes the species.
Temperatures are rising in the Artic. Glaciers are retreating. Sea ice is melting. Permafrost is thawing releasing methane and CO2 causing positive feedback. The Inupiaq people on the permafrost island of Shishmaref have evacuated. Dozens of other native communities are threatened.
Tuesday May 22, Climate Change Models: Predictions and Uncertainty (56 min)
Scientists around the world have developed systems for measuring temperature, precipitation, carbon dioxide, methane, carbon monoxide, hydrogen gas and other readings from which the climate record is built. These measurements are used in computer models to predict the weather. In recent decades, scientists have developed computer models to predict the effects of climate change. There is only one planet. We do not have a spare to experiment on. Computer models are the only known method to predict what will happen as the earth’s climate changes.
Accuracy of the data is crucial as is the laws and principles of physics fed into the super computer models. Scientists’ understanding of how climate change will affect the earth is continually changing as new information becomes available. For example, in the early 80’s it was assumed the Greenland ice sheet would melt slowly over many centuries. Scientists have been surprised by how much the ice sheet has melted in the past forty years. Through their investigations, scientists have a new understanding of the dynamics of ice sheet melting. The models must be revised with this new information.
The models have uncertainty, usually expressed as a range and that range can sometimes be quite large. Critics focus on model uncertainty to dismiss predictions. This documentary is an introduction to climate models and the world-wide systems of climate measurement and recording. It will not directly address the issue of uncertainty. That question will be address in a forthcoming documentary.
The Documentary Film & Discussion Series is in its seventh season at the Ashland Library.
For information on Transition Ashland, e-mail info@TransitionAshland.org.
The Documentary Film & Discussion Series meets every 2nd Thursday and 4th Tuesday of the month for an in-depth look at important topics of our day. The moderated discussions are often lively and thought provoking. All points of view are welcomed. For more information, call the library, 508-881-0134.
