Climate Change

1
Climate Change
Feb. 17, 1993
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
2
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)
3
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)
4
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
Climate meteorological conditions that
characteristically prevail in a region
Image from Wikipedia (see Geologic temperature
record)
5
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
Climate Change a shift of average weather
across a region
Image from Wikipedia (see Geologic temperature
record)
6
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
E.g., Eocene temperature was 4 6 C warmer than
today
Image from Wikipedia (see Geologic temperature
record)
7
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
E.g., Eocene temperature was 4 6 C warmer than
today
Eocene on Ellesmere Island, far north Canada
Modern day on Ellesmere Island, far north Canada
Images from www.thecanadianencyclopedia.com
8
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
E.g., Eocene seas were 100 - 150 m higher than
today
Image from www.thecanadianencyclopedia.com
9
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
E.g., Milankovitch Cycles Earths changing
orbit influences temperature with 41,000
100,000 yr periodicities
Image from Wikipedia (see Geologic temperature
record)
10
Earths Climate is also Dynamic Climate Change
(or Variation) Characterizes Earths History
E.g., Pleistocene glacial and inter-glacial
periods
Image from Wikipedia (see Geologic temperature
record)
11
Natural Climate Forcing (Physical processes
that influence Earths avg. temp.)
E.g., Pleistocene glacial and inter-glacial
periods
Image from Wikipedia (see Geologic temperature
record)
12
Natural Climate Forcing Orbital
Owing to other planets in our solar system,
Earths orbit varies over long time
scales e.g., eccentricity varies from 0.005 to
0.058
Hypothetical circular orbit, no eccentricity
Hypothetical orbit with0.5 eccentricity
Image from Wikipedia (see Milankovitch cycles)
13
Natural Climate Forcing Orbital
Earths axial tilt (obliquity) varies from 22.1
to 24.5
Image from Wikipedia (see Milankovitch cycles)
14
Natural Climate Forcing Orbital
Orbital forcing causes variation in solar heating
of the planet (orbit influences radiative
forcing, i.e., solar input)
Image from Wikipedia (see Milankovitch cycles)
15
Natural Climate Forcing Radiative
Image from Wikipedia (see Global Warming)
16
Natural Climate Forcing Radiative
Earths avg. temp. 14 C (57 F) Without the
atmospheres greenhouse effect it would be about
-18 C (-0.4 F)
Image from www.grida.no
17
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 isnt 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
18
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
19
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)
20
Anthropogenic Causes of Climate Change
Al Gore
(b. 1948) 45th U. S. Vice President Shared
Nobel Peace Prize (2007) with IPCC Academy Award
(2007) for the documentary filmAn Inconvenient
Truth
Photo from www.thegeneralist.co.uk
21
Anthropogenic Causes of Climate Change
The Keeling Curve
Image from NOAA
22
Anthropogenic Causes of Climate Change
IPCC predictions are for CO2 by 2100 500 to
1000 ppm with concomitant global temperatures
1.1 to 6.4 C higher
Image from www.epa.gov
23
Kyoto Protocol (1997)
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)
24
Montreal Protocol (1987)
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
25
Declining Glacial Thickness
Image from Wikipedia (see Global Warming)
26
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
27
Glacial retreat (loss) in the Alps
Photo by K. Harms looking down the glacial
valley below Lämmerenhütte Switzerland, October
2010
28
Glacial retreat (loss) in the Alps
Photo by K. Harms looking up the glacial valley
below Lämmerenhütte Switzerland, October 2010
29
Glacial retreat (loss) in the Alps
Photo by K. Harms of Lämmerenhütte Switzerland,
October 2010
30
Glacial retreat (loss) in the Alps
Photo by K. Harms the remnant glacier above
Lämmerenhütte Switzerland, October 2010
31
Decreasing oceanic pH
Tatoosh Island, Washington
Photo from Wikipedia figures from Wootton et al.
2008 Proceedings of the National Academy of
Science
32
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 tokeep pace with changing environments)
33
Climate Change Impacts Biota
Range map and image of polar bear (Ursus
maritimus) from Wikipedia
34
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)