1. +35% IPCC. AR4. 2007 Land use change

2. What is climate?: Average weather 30+ year averages for temperature, precipitation, wind patterns Source: NOAA, Local Climatological Data December Average Low: 35 º F (3º C) December 7 – 13, 2008 Colder than average

3. What is controversial about climate change? Undisputed: - CO 2 in the atmosphere warms the planet. - Humans are adding CO 2 to the atmosphere. - Adding additional CO 2 will change temperature and precipitation patterns (climate) - Climate change impacts humans and ecosystems, both harm and possible benefit, significant uncertainty. - Most of the observed warming over the 20th century has been due to anthropogenic climate change. Disputed: - The magnitude and timing of climate change: How much and when? - Attribution: Exactly how much change is anthropogenic, how much is natural?

4. Climate Science beginnings and method Gene-Baptiste-Joseph Fourier, 1826: The earth’s atmosphere traps heat. Svante Arrhenius, 1896: The scientific community began to consider that humans could actually change the climate. Richard Keeling, 1950s: Set up an observatory on Mauna Loa in Hawaii to monitor CO 2 concentrations in the atmosphere. Consensus on climate change is based on: historical observations mathematical (computer-run) models based on understood physics what-if scenarios of past and future climate

5. The Keeling Curve The Wilderness Society Publication, 2008, p. 12 - 14

6. What causes changes in climate? 3 ways to change the solar radiation balance of the earth Source: IPCC Working Group 2007, FAQs I. Changes in incoming solar radiation

7. What drives global climate? Uneven solar heating Rotating Earth: The Coriolis effect Image: NASA Aqua MODIS satellite True or False? Moist air is less dense than dry air

8. TRUE Moist air is less dense than dry air Figure 7.2, p. 149 PV = nRT, Pressure is proportional to Temperature

9. Solar heating varies with latitude Atmosphere circulates because the Earth is heated unevenly Near the equator, sunlight (shortwave radiation) hits from straight overhead, concentrating energy in small area Near the poles, shortwave radiation hits at a low angle, so the same amount of energy is spread out over a larger area Fig. 7.3

10. Net heat gain (low latitudes) Net heat loss (high latitudes) Energy in = Energy out

11. Climate Factor #1: Incoming Solar Radiation Milankovitch cycles: Natural variations in climate due to changes in incoming solar radiation.

12. Source: IPCC Working Group 2007, FAQs II. Changes in solar radiation reflected What causes changes in climate?

13. Changes in Solar Radiation Reflected Climate Factor #2: Albedo

14. % of Solar Radiation Reflected Climate Factor #2: Albedo

15. 1991 Eruption of Mt. Pinatubo in the Phillipines Source: http://en.wikipedia.org/wiki/Mount_Pinatubo Source: IPPC Working Group 2007, FAQs Climate Factor #2: Albedo

16. Source: IPCC Working Group 2007, FAQs III. Changes in longwave radiation reflected back to space What causes changes in climate?

17. Climate Factor #3: Atmospheric Chemistry Only infrared radiation absorbed, occurs in troposphere

18. Greenhouse effect Ozone layer Climate change is NOT related to the ozone thinning

19. Most Important Greenhouse Gases Source: U.S. EPA 2005 GHGsSource Examples Water: H 2 O Oceans, Rivers, Plants, Soil Carbon Dioxide: CO 2 Combustion, Respiration, Oceans,Volcanoes Methane: CH 4 Mining operations, Combustion, Animals, Wetlands, Oceans Other GHGs : Nitrous oxide (N 2 O), Ozone (near surface), Halocarbons http://www.for.gov.bc.ca

20. Instrumental Temperature Record and Carbon Dioxide Source: NOAA Δ Temperature ( C ) Δ Temperature ( F )

21. Measuring Ocean Heat Changes Argo Information Centre Photo courtesy of Sabrina Speich NASA, Visible Earth

22. Spring snowpack is projected to decline as more winter precipitation falls as rain rather than snow. Snowpack will melt earlier with warmer spring temperatures Pacific Northwest: Less summer water supply +4°F, +4.5% winter precip April 1 Snowpack

23. How can you stay informed? “Scientific method is designed to let us ask questions of nature without being fooled by the answer.” - Philip Meyer Real Climate science blog