The Current State of Our Climate - PowerPoint PPT Presentation

1 / 16
About This Presentation
Title:

The Current State of Our Climate

Description:

2001 - Third IPCC report: unprecedented global warming ... find surprisingly strong 'global dimming' (pollution) has masked intensity ... – PowerPoint PPT presentation

Number of Views:18
Avg rating:3.0/5.0
Slides: 17
Provided by: tmd0
Category:

less

Transcript and Presenter's Notes

Title: The Current State of Our Climate


1
The Current State of Our Climate
  • Prof. Tim Raymond
  • Chemical Engineering Dept.
  • Bucknell University
  • Focus the Nation Obstacles to Change
  • January 31, 2008

2
(No Transcript)
3
History and Background
  • 1800s - CO2 at 290 ppm T 13.6C
  • 1824 - Fourier discovers natural greenhouse
    effect of atmosphere
  • 1896 - Swedish scientist Arrhenius predicts
    greenhouse warming from CO2
  • 1960 - CO2 at 315 ppm (up 9 from 1800)
  • 1970s - Unusual weather creates speculation on
    global warming/cooling

4
History and Background
  • 1981 Hansen shows previous cooling trend was
    from aerosols (pollution)
  • 1985 Ice cores confirm correlation of CO2 and
    temperature
  • 1990 - First IPCC report world has been warming
    and future warming seems likely
  • 1995 - Second IPCC report detects "signature" of
    human-caused greenhouse effect warming

5
History and Background
  • 2001 - Third IPCC report unprecedented global
    warming
  • 2002 - Studies find surprisingly strong "global
    dimming" (pollution) has masked intensity of
    greenhouse warming
  • 2005 - Kyoto treaty goes into effect
  • 2007 - Fourth IPCC report unequivocal warming
  • 2007 - CO2 at 382 ppm T 14.5C (up 32)

6
Annual Average Global Surface Temperature
Anomalies 1880-2006
7
Annual Average Global Surface Temperature
Anomalies 1880-2006
Warming
Warming
Cooling from Pollution
8
(No Transcript)
9
Scientists know with virtual certainty that
  • Human activities are changing the composition of
    Earth's atmosphere.
  • The atmospheric buildup of CO2 and other
    greenhouse gases is largely the result of human
    activities.
  • An unequivocal warming trend of about 1.0 to
    1.7F occurred from 1906-2005.
  • The major greenhouse gases emitted by human
    activities remain in the atmosphere for periods
    ranging from decades to centuries.
  • Increasing greenhouse gas concentrations tend to
    warm the planet.

10
Body of Evidence
  • Increase of global average air temperature
  • Increase is ocean water temperatures
  • Decrease in Arctic sea-ice extent/thickness
  • Decrease in glacier/ice cap extent/mass
  • Rising global mean seal level
  • Changes in freeze/thaw, precipitation, etc.

11
(No Transcript)
12
Other Climate Variables
  • Oceans are becoming more acidic (CO2)
  • Observational evidence from all continents and
    most oceans shows that many natural systems are
    being affected
  • Permafrost melting, instability, ecosystems
  • Ecosystems early spring, animal ranges
  • Migrations timing and extent

13
Whats Not Certain?
  • How much warming will occur
  • How fast it will occur
  • How the warming will affect the rest of the
    climate system

14
Summary of Current State
  • Warming of the climate system is unequivocal
  • Directly related to human activities
  • Directly related to increases in GHGs
  • Global effects already visible

15
Sources
  • http//www.aip.org/history/climate/timeline.htm
  • Observations of climate change The 2007 IPCC
    Assessment, Testimony of Dr. Kevin E. Trenberth,
    Committee on Science and Technology, United
    States House of Representatives, February 8, 2007
  • IPCC, 1996 Climate Change 1995 The Science of
    Climate Change. Eds. J. T. Houghton et al.,
    Cambridge University Press, Cambridge, U.K. 572
    pp.
  • IPCC, 2001 Climate Change 2001 The Scientific
    Basis. Eds. J. T. Houghton, et al., Cambridge
    University Press, Cambridge, U.K. 881 pp.
  • IPCC, 2007 Climate Change 2007 The Scientific
    Basis. Eds. S. Solomon, et al., Cambridge
    University Press, Cambridge, U.K. (in press).

16
Sources
  • http//www.epa.gov/climatechange/science/index.htm
    l
Write a Comment
User Comments (0)
About PowerShow.com