1. The Influence of Human Activity on the Environment
Ms. Whipple – Brethren Christian High School

2. Improvements in agriculture health and medicine have produced a dramatic rise in the human population
This increase in population size leads to an increase in pollution and higher demand for the world’s resources

3. Humans are using up the earth’s resources, including fossil fuels.

4. Burning fossil fuels in cars and power stations produces carbon dioxide, sulphur dioxide and other greenhouse gases
carbon dioxide traps heat in the atmosphere and causes the temperature of the earth to rise.
This leads to disruption of the weather patterns ex. drought, floods

5. Sulphur dioxide will dissolve in rain producing Acid Rain
Acid rain damages trees and pollutes rivers and lakes.

6. Acid rain causes erosion of buildings and statues particularly if they are made of limestone

7. Deforestation
In many countries people are chopping down forests to provide timber or space for agriculture for the growing population
One popular method of clearing forests is “slash and burn” which destroys whole ecosystems.

8. This causes several problems
Burning the timber increases the level of carbon dioxide in the air
Less trees means less carbon dioxide absorbed for photosynthesis
Soil is eroded as it is exposed to the wind and rain
Less water is transpired into the atmosphere so there will be less rain in that area. This leads to Desertification (the creation of a desert where there once was forest or rainforest)
Many animal and plant habitats are destroyed causing extinction of species

9. Intensive Farming
Farming has become more intensive to provide a higher % yield from land
Many people regard intensive farming of animals to be cruel
In order to produce more food from the land farmers have to use more fertilisers and pesticides

11. Problems with Fertilisers
Fertilisers enable farmers to grow more food as they are replacing the nutrients removed from the soil by plants
However, if too much fertiliser is added and it then rains, the fertiliser finds its way into rivers and lakes
This causes the water plants to grow and as there is competition for light, some will die

12. Bacteria decay the dead plants and in so doing use up oxygen from the water
This means the fish suffocate and die
This process is called Eutrophication
Raw sewage pumped into rivers has the same effect
Places where this has occurred are called “dead zones”

15. Pesticides & Toxins Pesticides kill insects that will damage crops
They also kill harmless insects or can get washed into rivers and pollute the water
They may even end up in the food chain causing a build up of toxins in top predators called Biomagnification.

16. In the 1960s, DDT in the food chain threatened bird populations
In the 1960s, DDT in the food chain threatened bird populations. Many birds of prey came close to extinction

18. Sea Level Rise
Global sea level rise estimated to have risen cm over last 100 years
The next 100 years average sea level projected 50 cm higher

19. Sea Level Rise Consequences
The oceans are predicted to rise about 0.5 – 10.0 meter by 2100
Beach retreat and flooding pose a high risk along east coast and gulf state
Bluff collapse is greatest threat along California

20. Beach Erosion California
Beach erosion is a serious problem for coastal communities
86% of California coasts are classified as actively eroding
1 in 4 homes within 500 feet of coast will be lost to erosion in 60 years
Some causes:
Sea level rise
Building near coast
Efforts to reduce erosion

21. Beach Erosion California
2004
2005
2002
Santa Barbara, California

22. Ocean Pollution Sources
Oil spills
Toxic wastes
Debris
Raw sewage

23. Coral Reefs Provide natural habitat for 25% of marine life
Serve as breeding ground for marine organisms
Natural breakwater for strong waves

24. Coral Reefs Issues Pollution Destructive fishing methods
Human waste, fertilizer, and pesticides
Destructive fishing methods
Dynamite and cyanide
Global warming
Fragile living conditions
Increased CO2 Levels leading to
Ocean acidification
At the present rate of destruction, 70% of world’s coral reefs will be gone in the next years
Completely gone by 2100

25. What can we Do?

26. Organic Farming
This produces less food and is more expensive but it does not produce the pollution problems of intensive farming

27. Use farmyard manure as a fertiliser and set aside land for growth of wild plants

28. Biological Control of Pests
This means using natural predators to eat pests instead of pesticides
It does not have harmful effects

29. Develop alternative energy sources
Conserve our rapidly diminishing fossil fuel reserves by using solar power or wind power

30. Benefits of conserving endangered species
Ecotourism
Agricultural benefits
Species indicators
Maintaining diversity in gene pool

31. Be an Intelligent Consumer!!
Pay attention to where the food and things you buy come from. Money has power in this world, use it wisely and honourably.
Which foods require the most energy and water? Meat, Dairy, Nuts…Limit these
For example, one 1/3lb burger takes 660gallons of water to make!!
Choose sustainable seafood (go to Seafood Watch conservation/research/seafood-watch )

32. Sources: