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

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

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

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

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

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

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.

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

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

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

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”

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.

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

Sea Level Rise Global sea level rise estimated to have risen 10-25 cm over last 100 years The next 100 years average sea level projected 50 cm higher

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

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

Beach Erosion California 2004 2005 2002 Santa Barbara, California

Ocean Pollution Sources Oil spills Toxic wastes Debris Raw sewage

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

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 20-40 years Completely gone by 2100

What can we Do?

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

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

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

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

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

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 http://www.montereybayaquarium.org/ conservation/research/seafood-watch )

Sources: http://www.google.ca/url?sa=t&rct=j&q=Environmental+Issues+in+California+filetype:ppt&source=web&cd=4&ved=0CC4QFjAD&url=http%3A%2F%2Finstructional1.calstatela.edu%2Fpramire%2Fgeol%2520155%2520-%2520environmental%2520issues.ppt&ei=U4AuVdPwMs7ioASfw4HwDg&usg=AFQjCNE5JRlE79glGp-v-nf3iLYktMXYhw&bvm=bv.90790515,d.cGU http://www.google.ca/url?sa=t&rct=j&q=&source=web&cd=1&cad=rja&uact=8&ved=0CB8QFjAA&url=https%3A%2F%2Fwww.killeenisd.org%2FteacherDocs%2Fc8%2Fe20979%2Fdocuments%2FANewMenuItem-115422.ppt&ei=eX8uVYvlMJHToATgh4GYAQ&v6u=http%3A%2F%2Fs-v6exp1-ds.metric.gstatic.com%2Fgen_204%3Fip%3D24.43.39.14%26ts%3D1429112455665966%26auth%3D2duyahicelppt3n2gedj6tjb47x7grtf%26rndm%3D0.6662932629697025&v6s=2&v6t=7431&usg=AFQjCNEY5fY6RUVjCuxdj820o_t_tHZFBQ&bvm=bv.90790515,d.cGU