Earth

1
Earths Changing EnvironmentLecture 1

• The Next Mass Extinction?

2
Global Warming Scenarios

• The IPCC (Intergovernmental Panel on Climate
  Change) predicts that the global average
  temperature of the Earth will increase during the
  next 100 years. They use computer models to make
  predictions based on different scenarios of
  economic growth and greenhouse gas emissions.

3
IPCC Projections Global Temperature Change
4
IPCC Projection with History
5
Projections for 2050

• Models indicate that between now and 2050 there
  will be an increase in global mean temperature
  with a minimum equal to 0.8 oC (1.4 F) and
  maximum greater than 2 oC (3.6F).
• These temperature changes could have profound
  impacts

6
Extinction of Species
7
Recent Letter in Nature

• Extinction risk from climate change
• Nature 427, 145 - 148 (08 January 2004)
  doi10.1038/nature02121
• On the web at www.nature.com

8
Results of the Study

• When the average of the three methods and two
  dispersal scenarios is taken, minimal
  climate-warming scenarios produce lower
  projections of species committed to extinction
  (18) than mid-range (24) and maximum-change
  (35) scenarios.

9
Comment

• These estimates show the importance of rapid
  implementation of technologies to decrease
  greenhouse gas emissions and strategies for
  carbon sequestration.

10
Between 1/5 and 1/3 of all species will become
extinct in your lifetime!
11
BBC NewsFriday, 9 January, 2004, 0114
GMThttp//news.bbc.co.uk

• Climate change is the most severe problem we
  are facing today.
• - Sir David King, UK governments chief science
  adviser

12
Most of us ignored this report.

• Most people ignore environmental problems, do not
  understand them, remain inactive, hope everything
  works out well, or dont connect the science with
  reality (disconnect problem).

13
Are There Better Responses?

• Since environmental issues affect us, our
  friends, our families, and the world around us,
  we need take a responsible and defensible
  position.

14
Skeptical

• A skeptic does not accept the science and
  advocates business as usual.

15
Optimistic

• An optimist accepts the science, but advocates
  business as usual.

16
Activist

• An activist accepts the science, and advocates
  change.

17
How would you classify yourself on this or other
environmental issues?

• Skeptic
• Optimist
• Activist

18
Goal of this Course

• The goal of this class is to help you become a
  better informed and more thoughtful skeptic,
  optimist, or activist.

19
Another Goal

• My personal hope is that this course will help
  you become a thoughtful activist.