Climate Change and Public Health

Maine’s Climate Future(and past)

George L. JacobsonProfessor Emeritus of Biology, Ecology, and Climate

ChangeMaine State Climatologist

Climate Change InstituteThe University of Maine

April 7, 2010

Climate Change Institute (formerly Institute for Quaternary and Climate Studies)

• Climatology/Paleoclimatology• Historic climatology• Terrestrial paleoecology• Paleolimnology• Prehistoric archaeology• Glacial geology and glaciology • Atmospheric chemistry (incl. ice cores)• Geochemistry• Maine State Climatologist (GLJ)

“Maine Climate News” Web Site

Climate Change InstituteThe University of Maine

Central question:What is the natural variability of the earth’s climate, and what are the underlying mechanisms?

Weather or climate?

El Nino tendency over time(Nov. to Mar.)

All-time state record low temperature (– 50 F) 16 Jan 2009

OFFICIAL RECORD

20,000 years ago was the most recent glacial maximum

Maine under ice

Regular ice ages characterize the past million years

(information derived from ocean sediments)

warm

cold

Present interglacial (Holocene)

C.D. Keeling – IGY 1957

390 ppm as of February 2010

Projections show Maine becoming warmer and wetter in all regions of the state.

Was this winter a taste of late-21st Century norms in Maine?

Maine’s climate is highly compressed: equal to that of northern Europe

Maine’s steep climate gradient produces interesting patterns of range limits in plants.

Plant-hardiness zones have been shifting northward

Lakes have become ice-free earlier in the year

Range of deer ticks is spreading northward in recent years.

Future change are just the opposite of what happened in the past 1000 years --- southward expansion of spruce during a

cool period.

Sea-level rise is likely to accelerate

Courtesy UM Prof. Gordon Hamilton

Implications for Maine of global instabilities caused by climate change (broadly defined):

• Potential demand for resources (water, food, space, etc.)• Economic disruptions of many kinds• National security instabilities• Cumulative demand for health-related services &

resources• Many others…

Discussion?

Records of atmospheric N2O and of Dansgaard–Oeschger events over a 16,000-year interval during the last ice age.

Schmittner & Galbraith (2008) Nature 456:373-376.