The document discusses three environmental issues of interest to geographers: ozone depletion, greenhouse warming effect, and El Nino. It provides details on the causes and effects of ozone depletion, including the discovery of the ozone hole over Antarctica in 1975. The production and use of CFCs is identified as the main cause of ozone depletion. The document also discusses the phenomenon of global warming, noting the hottest years on record and trends of rising global temperatures, glacial melting, higher sea levels, and more severe droughts.

1. HUMAN GEOGRAPHY & the NATURAL
ENVIRONMENT
THE HUMAN IMPACT
The relationship between human society and the natural environment is central to human geography.
Human history spans 6 million years or more, but the expansion of humanity to unprecedented
numbers has taken only two centuries. This expansion has had an unprecedented impact on the
natural environment.
Although there are many areas of environmental concern, both natural and human created, the
three currently of particular interest and concern to geographers are ozone depletion, greenhouse
warming effect, and El Nino.

2. OZONE DEPLETION
The ozone layer exists between an altitude of 10 and
40 miles above the Earth’s surface and it absorbs
potentially lethal quantities of ultra-violet radiation.
Concern about ozone depletion occurred in 1975
when a hole in the ozone layer was discovered over
Antarctica.
The ozone hole appears each Antarctic spring and
fluctuates in size.
Of concern to scientists is the growing size of the
hole and the length of time the hole remains wide
open.

4. CAUSES OF OZONE DEPLETION:
A. JET AIRCRAFT C. CFC’S
B. NUCLEAR EXPLOSIONS D. AIR POLLUTION
DETRIMENTAL EFFECTS OF OZONE DEPLETION:
A. SKIN CANCER C. CATARACTS
B. BIRTH DEFECTS D. DAMAGE TO FARM CROPS
CURRENTLY:
In 1987, many nations, including the U.S., banned the production and use of
CFC’s.
FUTURE IMPLICATIONS:
Will ozone depletion change human life-styles?
Will ozone depletion hurt food production?

7. GLOBAL WARMING

9. “Some of the ice we have here is already gone from the mountains.” (L. Thompson)

12. Increased worldwide urbanization is exasperating the global warming phenomenon – why?
Have you noticed that the average temp. in urban areas is higher than that in rural
areas?

13. The concern is over the rate of
warming over a limited period of
time.
Scientists have been closely
studying the correlation between
CO2 production and the steady
rise in global temperature.

14. HOTTEST YEARS on RECORD:
1. 2006
2. 2005
3. 2004
4. 1998
5. 2002

15. CURRENT CLIMATE TRENDS
Global temperatures are on the rise and
the consequences include glacial melting, …

17. …, resulting in higher sea levels, …

18. … coastal flooding (“Things that normally happen in geologic time are happening during the
span of a human lifetime”), and ….

20. …. more severe droughts, which are causing the
Great Lakes to dangerously “dry up,” and ….

21. …. accelerating desertification
throughout the world.