A1257278361KRmtU - PowerPoint PPT Presentation
1 / 12
Title:
A1257278361KRmtU
Description:
the arctic ice cap has lost 48% of its thickness since 1970... 1998 - Warmest year on. Mean annual 1998. temperatures departures. from normal ... – PowerPoint PPT presentation
Number of Views:36
Avg rating:3.0/5.0
Title: A1257278361KRmtU
1
Is Climate Changing?
As of 2001
- the growing season on the prairies has
lengthened by 12 days since 1960 - the arctic ice cap has lost 48 of its thickness
since 1970 - the arctic ice cap has lost 40 of its summer
area since 1975 - the mean sea level in equatorial regions has
risen 20 cm since 1980
2
How do we know climate change is happening?
- United Nations Intergovernmental Panel on
Climate Change scientists agree that human
activity has affected the global climate - Temperature records to 1860
- Ice and sediment core data evidence dating back
thousands of years - Tree rings give clues to climate variation
- Computer modeling Canadian model is among the
best in the world
3
The Greenhouse Effect
4
WHAT ARE THE GREENHOUSE GASES ?
Water vapour the most common gas
Carbon dioxide released through burning fossil
fuels
Methane from wetlands, rice paddies, Animal
digestive processes, landfills and sewage
treatments
Nitrous oxide from soils and the ocean
Ozoneexists naturally in the upper atmosphere
Halocarbons human-made chemicals
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
Modeling Major Climatic Changes
IPCC WGI 2001
9
Global Climate Change Indicators
- Increased average annual temperatures
- Changes in seasonal average temperatures
- Greater fluctuation in annual and seasonal
precipitation - Changes to global weather patterns
- Decreased overall rates of evapotranspiration
- Melting permafrost in Northern regions
10
Projected temperature increase - summer 2090
(June, July, August)
Adaptation Impacts Research (AIR) Group,
Environment Canada, 1999
11
Projected temperature increase - winter 2090
(December, January, February)
Source Adaptation and Impacts Research (AIR)
Group, Envionment Canada, 1999
12
Mean annual 1998 temperatures departures from
normal (Normal 1951 to 1980 mean)
Source Environment Canada, Atmospheric
Service, Climate Research Branch
Recommended
CrystalGraphics Presentations
