Climate Change Photo of glacial retreat on Mount Kilimanjaro (Feb to Feb. 2000) from Wikipedia; Map of Africa from Feb. 17, 1993 Feb. 21, 2000

Image from Wikipedia (see “Climate”) Temperature Weather Patterns are Dynamic e.g., monthly variation

Image from Wikipedia (see “Climate”) Precipitation Weather Patterns are Dynamic e.g., monthly variation

Image from Wikipedia (see “Geologic temperature record”) Climate Change – a shift of average weather across a region Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History

Image from Wikipedia (see “Geologic temperature record”) E.g., Eocene temperature was 4 – 6 °C warmer than today Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History

Images from Eocene on Ellesmere Island, far north Canada Modern day on Ellesmere Island, far north Canada E.g., Eocene temperature was 4 – 6 °C warmer than today Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History

Image from E.g., Eocene seas were m higher than today Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History

Image from Wikipedia (see “Geologic temperature record”) E.g., Milankovitch Cycles –Earth’s changing orbit influences temperature with ~41,000 & ~100,000 yr periodicities Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History

Image from Wikipedia (see “Geologic temperature record”) E.g., Pleistocene glacial and inter-glacial periods Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History

Image from Wikipedia (see “Geologic temperature record”) E.g., Pleistocene glacial and inter-glacial periods Natural Climate “Forcing” (Physical processes that influence Earth’s avg. temp.)

Image from Wikipedia (see “Milankovitch cycles”) Owing to other planets in our solar system, Earth’s orbit varies over long time scales; e.g., eccentricity varies from to Hypothetical circular orbit, no eccentricity Hypothetical orbit with 0.5 eccentricity Natural Climate “Forcing” Orbital

Image from Wikipedia (see “Milankovitch cycles”) Earth’s axial tilt (obliquity) varies from 22.1° to 24.5° Natural Climate “Forcing” Orbital

Image from Wikipedia (see “Milankovitch cycles”) Orbital forcing causes variation in solar heating of the planet (a.k.a. radiative forcing) Natural Climate “Forcing” Orbital

Image from Wikipedia (see Global Warming) Natural Climate “Forcing” Radiative

Image from: Earth’s avg. temp. = 14 °C (57 °F) Without the atmosphere’s greenhouse effect it would be about -18 °C (-0.4 °F) Natural Climate “Forcing” Radiative

This isn’t very surprising, since clouds that form from transpired water are absent over wide, treeless rivers & their immediate floodplains in the Amazon Basin At regional scales, deforestation leads to drying (and heating), owing primarily to reduced evapotranspiration and water-holding capacity of soil Image from: Anthropogenic Causes of Climate Change

E.g., cities in the Brazilian Amazon are warmer and drier than those areas were before they became urban centers At regional scales, deforestation leads to drying (and heating), owing primarily to reduced evapotranspiration and water-holding capacity of soil These examples are not global, but they demonstrate that humans can alter regional climate patterns E.g., much of Greece is warmer and drier today because of deforestation in earlier millennia Anthropogenic Causes of Climate Change

International Panel on Climate Change (IPCC) est by the United Nations Taking all the accumulated evidence into account, anthropogenic increases in greenhouse gases are the principal causes of modern global warming; i.e., we are experiencing an anthropogenically enhanced greenhouse effect Image from Wikipedia (see “Greenhouse gas”) Anthropogenic Causes of Climate Change

Photo from: Al Gore (b. 1948) 45 th U. S. Vice President Shared Nobel Peace Prize (2007) with IPCC Academy Award (2007) for the documentary film: An Inconvenient Truth Anthropogenic Causes of Climate Change

Image from NOAA The Keeling Curve Anthropogenic Causes of Climate Change

Image from IPCC predictions are for [CO 2 ] by 2100: 500 to 1000 ppm; with concomitant global temperatures 1.1 to 6.4 °C higher Anthropogenic Causes of Climate Change

Legally binding treaty through 2012 (when ratified by states) intended to enact resolutions from the United Nations’ Framework Convention on Climate Change (1992) to achieve “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system” Image from Wikipedia (see “Kyoto Protocol”) Green = signed & ratified Red = signed, but not ratified Grey = non-signatory Kyoto Protocol (1997)

Treaty to enact resolutions from the United Nations’ Vienna Convention on the Protection of the Ozone Layer (1985) to “protect the ozone layer by taking precautionary measures to control equitably total global emissions of substances that deplete it, with the ultimate objective of their elimination” Montreal Protocol (1987) Image from Wikipedia (see “Ozone depletion”) – NASA image of largest Antarctic ozone hole ever recorded September 2006

Image from Wikipedia (see “Global Warming”) Declining Glacial Thickness

Photo of glacial retreat on Mount Kilimanjaro (Feb to Feb. 2000) from Wikipedia; Map of Africa from Glacial retreat (loss) on Mt. Kilimanjaro Feb. 17, 1993 Feb. 21, 2000

Glacial retreat (loss) in the Alps Photo by K. Harms – looking down the glacial valley below Lämmerenhütte; Switzerland, October 2010

Glacial retreat (loss) in the Alps Photo by K. Harms – looking up the glacial valley below Lämmerenhütte; Switzerland, October 2010

Glacial retreat (loss) in the Alps Photo by K. Harms of Lämmerenhütte; Switzerland, October 2010

Glacial retreat (loss) in the Alps Photo by K. Harms – the remnant glacier above Lämmerenhütte; Switzerland, October 2010

Photo from Wikipedia; figures from Wootton et al Proceedings of the National Academy of Science Decreasing oceanic pH Tatoosh Island, Washington

Altered expression of traits (owing to phenotypic plasticity; e.g., phenology) Range shifts (especially upslope and to higher latitudes) Adaptation (to changing environment) Extinctions (when range shifts and adaptation fail to keep pace with changing environments) Climate Change Impacts Biota

Range map and image of polar bear (Ursus maritimus) from Wikipedia Climate Change Impacts Biota

From Doran & Zimmerman (2009) Eos (formerly Transactions of the American Geophysical Union) Opinions on Climate Change Do you think human activity is a significant contributing factor in changing mean global temperature?