Climate Expert Michael MacCracken to Talk on “Global

Warming: The Increasing Effects of Human Activities on Climate”

at Middlebury College on April 28

Michael MacCracken, a senior figure in the United

States Global Change Research Program (USGCRP), will give a talk,

titled “Global Warming: The Increasing Effects of Human Activities

on Climate,” at Middlebury College on Wednesday, April 28

at 7 p.m. The event will take place in the library of the Geonomics

Center for International Studies on Hillcrest Road off College

Street (Route 125), and is free and open to the public.

MacCracken is executive director of the National

Assessment Coordination Office of USGCRP, the portion of the program

responsible for assessing how global warming will impact the United

States. His talk is the 1999 Scott Margolin Lecture in Environmental

Affairs.

The lecture will include a number of topics related

to the cause of global warming, the evidence that it is occurring,

and its impact on the world. McCracken will discuss the fact that

emissions from fossil fuel combustion, deforestation, and non-sustainable

agriculture are releasing carbon dioxide, methane, and other greenhouse-effect

gases into the atmosphere, thereby altering atmospheric composition.

He will point to evidence-including rising ocean

and land temperatures, melting glaciers, the rising sea level,

and increasing rates of precipitation-that suggests human activities

are now having a discernible influence on the global climate.

MacCracken also will discuss prospects for the next

century that global average temperatures will rise one to three

and a half degrees centigrade, and that the sea level will rise

by 10 to 95 centimeters by the year 2100 if emissions are not

reduced below projections, and he will also review substantial

changes that will occur even if emissions start to be curtailed

early in the next century. He will show how these types of change

will lead to a range of possible environmental impacts that will

affect every region of the world.

Contact Dan Bedford of the Middlebury College geography

department at 802-443-5210 or bedford@middlebury.edu.