Feb 17 1993 Climate Change Feb 21 2000

Feb. 17, 1993 Climate Change Feb. 21, 2000 Photo of glacial retreat on Mount Kilimanjaro (Feb. 1993 to Feb. 2000) from Wikipedia; Map of Africa from www. admin. uio. no

Weather Patterns are Dynamic e. g. , monthly variation Weather – the state of the atmosphere at a given time and place Temperature Image from Wikipedia (see “Climate”)

Weather Patterns are Dynamic e. g. , monthly variation Weather – the state of the atmosphere at a given time and place Precipitation Image from Wikipedia (see “Climate”)

Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History Climate – meteorological conditions that characteristically prevail in a region Image from Wikipedia (see “Geologic temperature record”)

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

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

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

Earth’s Climate is also Dynamic Climate Change (or Variation) Characterizes Earth’s History E. g. , Eocene seas were 100 - 150 m higher than today Image from www. thecanadianencyclopedia. com

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

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

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

Natural Climate “Forcing” Orbital Owing to other planets in our solar system, Earth’s orbit varies over long time scales; e. g. , eccentricity varies from 0. 005 to 0. 058 Hypothetical circular orbit, no eccentricity Image from Wikipedia (see “Milankovitch cycles”) Hypothetical orbit with 0. 5 eccentricity

Natural Climate “Forcing” Orbital Earth’s axial tilt (obliquity) varies from 22. 1° to 24. 5° Image from Wikipedia (see “Milankovitch cycles”)

Natural Climate “Forcing” Orbital forcing causes variation in solar heating of the planet (orbit influences radiative forcing, i. e. , solar input) Image from Wikipedia (see “Milankovitch cycles”)

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

Natural Climate “Forcing” Radiative Earth’s avg. temp. = 14 °C (57 °F) Without the atmosphere’s greenhouse effect it would be about -18 °C (-0. 4 °F) Image from: www. grida. no

Anthropogenic Causes of Climate Change At regional scales, deforestation leads to drying (and heating), owing primarily to reduced evapotranspiration and water-holding capacity of soil 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 Image from: http: //earthobservatory. nasa. gov

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

Anthropogenic Causes of Climate Change International Panel on Climate Change (IPCC) est. 1988 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 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 Photo from: www. thegeneralist. co. uk

Anthropogenic Causes of Climate Change The Keeling Curve Image from NOAA

Anthropogenic Causes of Climate Change IPCC predictions are for [CO 2] by 2100: 500 to 1000 ppm; with concomitant global temperatures 1. 1 to 6. 4 °C higher Image from www. epa. gov

Montreal Protocol (1987) – re CO 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 [e. g. , CFCs], with the ultimate objective of their elimination” September 2006 Image from Wikipedia (see “Ozone depletion”) – NASA image of largest Antarctic ozone hole ever recorded

Kyoto Protocol (1997) – re CO 2 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” Green = signed & ratified Red = signed, but not ratified Grey = non-signatory Image from Wikipedia (see “Kyoto Protocol”) Re CO 2 in comparison to CO – “This is an altogether higher orbit, involving much heavier lifting. ” Mc. Kibben (2008)

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

Feb. 17, 1993 Glacial retreat (loss) on Mt. Kilimanjaro Feb. 21, 2000 Photo of glacial retreat on Mount Kilimanjaro (Feb. 1993 to Feb. 2000) from Wikipedia; Map of Africa from www. admin. uio. no

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

Decreasing oceanic p. H Tatoosh Island, Washington Photo from Wikipedia; figures from Wootton et al. 2008 Proceedings of the National Academy of Science

Fig. 1. (A) Linkages between the buildup of atmospheric CO 2 and the slowing of coral calcification due to ocean acidification. O Hoegh-Guldberg et al. Science 2007; 318: 1737 -1742 Published by AAAS

Climate Change Impacts Biota 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

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

Opinions on Climate Change John Oliver re Climate Change “debate” https: //www. youtube. com/watch? v=cju. GCJJUGsg