HUMAN GEOGRAPHY & the NATURAL ENVIRONMENT THE HUMAN IMPACTThe 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 unprecedentednumbers has taken only two centuries. This expansion has had an unprecedented impact on thenatural environment.Although there are many areas of environmental concern, both natural and human created, thethree currently of particular interest and concern to geographers are ozone depletion, greenhousewarming effect, and El Nino.
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.
CAUSES OF OZONE DEPLETION: A. JET AIRCRAFT C. CFC’S B. NUCLEAR EXPLOSIONS D. AIR POLLUTIONDETRIMENTAL EFFECTS OF OZONE DEPLETION: A. SKIN CANCER C. CATARACTS B. BIRTH DEFECTS D. DAMAGE TO FARM CROPSCURRENTLY:In 1987, many nations, including the U.S., banned the production and use ofCFC’s.FUTURE IMPLICATIONS:Will ozone depletion change human life-styles?Will ozone depletion hurt food production?