Human Impact l LAND RESOURCES l FOREST RESOURCES

Human Impact l. LAND RESOURCES l. FOREST RESOURCES l. OCEAN RESOURCES l. AIR RESOURCES l. WATER RESOURCES l. OZONE DEPLETION l. GLOBAL WARMING

Land Resources What is happening? Plowing removes the roots that hold the soil in place, increasing the rate of Soil erosion SOIL EROSION – is the wearing away of surface soil by water and wind. Desertification- the process of turning once productive areas into deserts from a combination of farming, overgrazing, and drought.

Land Resources Why is it a problem? Soil is a renewable resource, however it can be permanently damaged if mismanaged What is being done? Contour plowing- fields are plowed across the slope of the land to reduce erosion Leaving stems and roots of the previous year’s crops in place to hold soil

Forest Resources What is Happening? Deforestation- loss of forest which leads to severe erosion Why is this a problem? Old growth forest can be considered a nonrenewable resource because it would take centuries to reproduce Forests provide O 2 and remove CO 2 from the atmosphere They also store nutrients and provide food and habitat to organisms

Forest Resources What is being Done? Tree farms can be planted and harvested efficiently making them fully renewable resources Tree geneticists are also breeding new, faster-growing tree varieties that produce high- quality wood.

Ocean Resources What is happening? Overfishing- fish stocks in many fisheries are being harvested faster than they reproduce. Why is this a problem? People depend on the ocean as a major source of protein, both from finfish and from shellfish With the amount of fish caught each year increasing the fish cannot reproduce fast enough to keep up

Ocean Resources What is being done? Limiting the catch of fish Certain fishing grounds have been temporarily closed Aquaculture- farming of aquatic organisms

Air Resources What is happening? Smog- a mixture of chemicals that occurs as a gray-brown haze in the atmosphere. This is due primarily to automobile exhausts and industrial emissions Pollutant- a harmful material that can enter the biosphere through air, land or water The burning of fossil fuels can release pollutants that cause smog and other problems in the atmosphere.

Air Resources Why is it a problem? This leads to toxins that enter the mouth, nose and lungs causing health problems over the long term. Gases released from the burning of fossil fuels combine with water vapor to form ACID RAIN Acid rain kills plants, and changes the chemistry of soils What is being done? Technology to control emissions from factory smokestacks Strict automobile emission standards and clean air regulations

Water Resources What is happening? Pollution such as OIL SPILLS threatens our water supply Improperly discarded chemicals can enter streams and rivers Domestic sewage entering or water ways causing increase in bacteria growth

Water Resources Biomagnification

Water Resources Why is this a problem? Fresh water is used daily for everything from drinking and washing to watering crops and making steel. Although water is a renewable resource, the total supply of fresh water is limited What is being done? Conservation by: drip irrigation, and consumer awareness of conservation

Ozone Depletion What is happening? Chemicals called CFC’s which were once widely used in aerosol cans, the production of plastics and as coolants in freezers, refrigerators and air conditioners have caused a hole in our ozone layer and this hole is continuing to grow

Ozone Depletion Why is this a problem? The ozone layer absorbs a great deal of harmful UV rays before it reaches the earth’s surface. As the ozone layer is depleted UV exposure can cause sunburns, cancer, eye damage and decrease an organism’s resistance to disease What is being done? The US has joined many other nations to phase out the use of CFCs

Global Warming What is happening? An increase in the average temperature of the biosphere. Over the past 120 years global temperatures have risen. 5 degrees Celsius CO 2 and other gases are being released into the atmosphere and being retained causing more heat.

Global Warming Why is this a problem? Polar ice caps will continue to melt and could rise enough to flood some low lying coastal areas Storms and other weather disturbances could become more frequent and severe Heat favors rodents weeds and insect that reproduce and spread quickly What is being Done? Alternate energy sources are being researched to reduce or stop the burning of fossil fuels that release gases into the atmosphere that retain heat.