Human Impacts Deforestation / Fragmentation Pesticides Global warming Depletion of ozone layer Acid rain

Global Warming 1990s was the hottest decade, 1998 hottest year on record (since 1861) ~ 10% loss of snow cover since 1960s. Sea level has risen by cm during the 1900s. El Niño has been more frequent, persistent, and intense since 1970s (relative to past 100 years).

Global Warming (Land Surface)

Global Warming (Ocean) Levitus, S., Antonov, J.I., Boyer, T.P., & Stephens, C. (2000) Warming of the World Ocean. Science, 287,

Some Factors Influencing Climate Fluctuations in solar energy Orbital parameters Planetary albedo (reflectivity) –Aerosols (things in the air) –Ice, water, land, plant surfaces Anthropogenic factors (Greenhouse Effect) –Burning of fossil fuels –Deforestation

The Greenhouse Effect

Other Greenhouse Gasses

Global Warming: Causes

Global Warming: Human Influence “Our ability to quantify the human influence on global climate is currently limited because the expected signal is still emerging from the noise of natural variability…’” – 1995 IPPC Summary, cited by 2001 EPA global warming web site “In the light of new evidence... most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.” – 2001 IPCC Summary

Global Warming: Predictions IPCC 1995 –1.0 – 3.5 °C –1.8 – 6.3 °F IPCC 2001 –1.4 – 5.8 °C –2.5 – 10.4 °F

Global Warming: Predictions Uncertainty Analysis of Global Climate Change Projections, M. D. Webster, et al. Joint Program on the Science and Policy of Global Change, MIT Schneider, S.H What is 'dangerous' climate change? Nature 411: 17 – 19.

Changes in Phenomenon Confidence in observed changes Confidence in projected changes  max. temps over nearly all land areas LikelyVery likely  min. temps,  frost days over nearly all land areas Very likely  intense precipitation events Likely over many N. hemisphere mid- to high latitude areas Very likely over many areas  summer continental drying and risk of drought Likely in a few areas Likely over most mid- latitude continental interiors.  in tropical cyclone precipitation Insufficient data for assessment Likely in some areas Global Warming: Impacts

Demographic Changes Janzen, F. J Climate change and temperature-dependent sex determination in reptiles. Proceedings of the National Academy of Science of the United States of America 91:7487–7490. An increase in temperature of 4 °C would require a shift in mean temperature threshold of 35 SD!

Geographic Range Changes N range limit of 52 spp. 65% expanded N 34% stable 2% contracted S Parmesan, C., N. et al Poleward shifts in geographical ranges of butterfly species associated with regional warming. Nature 399:579–583.

Altitudinal Changes Climate changes more rapidly with elevation (1° C / 160 m) than it does with latitude (1° C / 150 km For 9 species in Swiss Alps with detailed records: –Observed rate of upward shift 1–4 m per decade. –Predicted rate of upward shift 8–10 m per decade based on the change in mean temperature over the last 90 years May indicate that these plants are unable to respond successfully to more rapid climate change. Grabherr, G., M. Gottfried & H. Pauli Climate effects on mountain plants. Nature 369:448

Phenological Changes Breeding datePied Flycatcher13 days24Slater 1999 Breeding dateTree Swallow5–9 days33Dunn & Winkler 1999 Breeding dateGreat Tit11.9 days27McCleery & Perrins 1998 Breeding date2 bird species30 days35MacInnes et al Breeding dateMexican Jay10.1 days27Brown et al Migration date4 bird species11.9 days50Mason 1995 Migration date39 bird species5.5 days50Oglesby & Smith 1995 Migration dateAmerican Robin14 days19Inouye et al McCarty, J. P. Ecological Consequences of Recent Climate Change. The Journal of the Society for Conservation Biology 15 (2),

Phenological Changes Inouye, D. W., et al Climate change is affecting altitudinal migrants and hibernating species. PNAS 97:1630–1633.

Global Warming Consequences Kiesecker, J.M., Blaustein, A.R., & Belden, A.K. (2001) Complex causes of amphibian population declines. Nature, 410,

Global Warming Consequences Kiesecker, J.M., Blaustein, A.R., & Belden, A.K. (2001) Complex causes of amphibian population declines. Nature, 410,

What’s Being Done to Control Global Warming? International policy National policy Personal policy

Greenhouse Gas Emissions

Greenhouse Gas Emissions Emissions per person have increased about 3.4% between 1990 and % of these emissions are from burning fossil fuels to generate electricity and power our cars. You can affect 32% of the total emissions per person –electricity, waste production, personal transportation The other 68% of emissions are affected by industry –types of offices we use, how our food is grown, etc.