Climate Change Science Rapid change and “tipping points” Jim Quinn Information Center for the Environment UC Davis

National Academy of Sciences National Research Council

Increasing CO 2

Rising sea level

Record temperatures

Great Barrier Reef Bleaching

Projected sea ice

“Tipping Points”?

National Academy of Sciences

National Academy Tipping Point Candidates large, abrupt changes in ocean circulation and regional climate; reduced ice in the Arctic Ocean and permafrost regions; large-scale clathrate release; changes in ice sheets; large, rapid global sea-level rise; growing frequency and length of heat waves and droughts; effects on biological systems of permafrost/ground thawing (carbon cycle effects); phase changes such as cloud formation processes; and changes in weather patterns, such as changes in snowpack, increased frequency and magnitude of heavy rainfall events and floods, or changes in monsoon patterns and modes of interannual or decadal variability.

Possible “Tipping Points”

Rapid breakup of tidewater glaciers

Antarctic Ice Shelves

Larson Ice Shelf 31 Jan. 2002

Larson Ice Shelf 5 April 2002

Accelerating Greenland Glaciers NASA

Melting Ice Cap Surface

Impacts – More Extreme Weather? Hurricane Katrina – August 28, 2005

Cyclone Nargis Floods Burma (Myanmar) 2008

Size and Frequency of Tropical Storms

Normalized damage

Methane in hydrates (“clathrates”) and permafrost

NAS Assessment of “Tipping Point” Threats (physical processes p.1 of 3)

NAS Assessment of “Tipping Point” Threats (biology)

Uncertainties in adaptation and mitigation Best models Clouds and albedo Ocean-atmosphere coupling Tipping points? Scale Mitigation goals (primary productivity? Biomass? Impact on warming?) Policy

Adaptation for the Rich Thames Barrier

Extreme events

Stay Cool!