January 10, 2006 Global and Regional Climate Change: Causes, Consequences, and Vulnerability Climate Science in the Public Interest UW Climate Impacts Group Jeremy S. Littell Climate Impacts Group, UW Center for Science in the Earth System 10 January, 2007

January 10, 2006 Mean January–December Temperature in the Conterminous United States (1895–2006) Data from the National Climatic Data Center, NOAA –2006 Period of record mean The calendar year 2006 was the warmest in the 112-year historical surface temperature record for the conterminous U.S.A was the first time that a mean annual temperature of 55F was recorded. The year's value was exactly 55.0F.

January 10, 2006

Climate System Overview Global climate change Physical components of the climate system – atmosphere – cryosphere – biosphere – hydrosphere – land surface (cryo, bio, lithospheres) Linda Brubaker, Chris Earle (UW)

January 10,

January 10, 2006 Atmosphere

The atmosphere is one part of the “heat engine” of the earth

January 10, 2006 Human sources: Fossil fuel burning (CO 2, CH 4, N 2 0) Deforestation and land use change (CO 2 ) Agricultural practices (CO 2, CH 4, N 2 0) Energy extraction (CO 2, CH 4 ) Ruminant (e.g., cows) (CH 4 ) Cement production (CO 2 ) Landfills (CH 4 ) Natural sources Wetlands (CH 4 ) Oceans, soils (CO 2, N 2 0) Decomposition of organic matter (CO 2, CH 4 ) Greenhouse gases (water vapor, CO 2, CH 4, N 2 O, O 3 ) play a critical role in determining global temperature Rapid increases in greenhouse gases are changing this balance

January 10, 2006 Cryosphere - 9-days composite image around the North Pole, generated from GLI L1B data during April 2-10, 2003

January 10, 2006 New Snow: 0.8 Melting Snow: 0.7 Melting Sea Ice: 0.65 Lake Ice: 0.5 Tundra: 0.2 Arctic Ocean: 0.07

January 10, 2006

Modis NDVI May-July 2000

January 10, 2006 Aug-Oct MODIS NDVI

January 10, 2006 Nov 2000-Jan MODIS NDVI MODIS NDVI

January 10, 2006 Feb-Apr MODIS NDVI

January 10, 2006 The hydrosphere integrates atmosphere, cryosphere, land surface

January 10, 2006

CO2 concentration levels – –Appear to be higher than any time in past ~ 23 million yrs The human footprint – –Human activities altering the climate system – –Human systems based on expectation of certain climate conditions – –Population growth, political boundaries, resource dependency/depletion, habitat fragmentation limit ability of natural and human systems to tolerate rapid change Present Day Climate Change: What is Different?

January 10, 2006 Atmos. concentration of CO 2 has increased 31% since 1750; CH 4 increased 150% CO 2 appears to be higher than any time in past ~23 million yrs ~70% of CO 2 emissions come from fossil fuel burning; 50% CH 4 from human activities Account for ~ 60% and ~20% of GHG warming (~53% combined) Carbon Dioxide & Methane

January 10, 2006 Changes in Global Average Temp Changes in Global Average Temp Since 1900, the planet has warmed 0.6  0.2°C (1.1  0.4°F) Source: IPCC

January 10, 2006 Source: Mann et al. 1998, IPCC 2001

January 10, 2006 Natural climate influence onlyHuman climate influence only All Climate Influences Observational record best matched when natural climate influences (solar variation and volcanic activity) and increases in CO2 concentrations are both included. Source: IPCC, 2001 Gaining perspective through climate modeling

January 10, 2006 Temperature increases in the late 20 th century are widespread. Temperature decreases are rare and small in comparison. Precipitation is more variable in space and time.