Environmental Problems Today

1. Overusing Resources:-Two Main Types:

*Renewable: sunlight, forests, air, soil

*Nonrenewable: minerals, gems, & fossil fuels

* Right now, we over use both types, but esp. nonrenewable resources

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2. Energy Consumption From Fossil Fuels:

* Oil, coal, & natural gas provide 80% of energy used in industrialized countries

* NONRENEWABLE & causes pollution

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3. Pollution: = any physical, chemical, or

biological change that negatively affects organisms or negatively alters the environment

*Includes air, water, & soil pollution

*At least 1.1 billion people lack an adequate supply of safe drinking water

*More than twice that don’t have modern sanitation

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4. Global climate change:

* Human activities release carbon dioxide (CO2) & other greenhouse gases that trap heat in the atmosphere

* Over the past 200 years, atmospheric CO2 has increased by 35%

* By 2100… global temps will probably warm 1.5 to 6C (2.7-11 F)

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5. Overpopulation

*More people = increased use of resources = destruction of environment

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6. Loss of Biodiversity:

*Biodiversity: diversity of organisms (different species) in an area* Over the past century, more than 800

species have gone extinct & at least 10,000 species are now threatened

Tasmanian tiger- extinct 1936

Great Auk

- extinct 1844

tree kangaroo- endangered

cheetah- endangered

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*Biodiversity

*Number species on Earth known & described is ~1.7 million

*Estimated to actually be ~ 10 million

*INTERESTING FACT: Insects constitute the greatest number of species (nearly 1,000), followed by plants, arachnids, fungi, mollusks, and vertebrates 3:32

*Why Biodiversity is Important:

*We depend on healthy ecosystems and many organisms for balanced nutrient cycles & energy flow. *Every species is dependent on or depended upon by at least one other species.

*We use organisms for food, clothing, shelter, & medicine. *About 25% of drugs prescribed in the US

are derived from plants. Almost all antibiotics are derived from chemicals found in fungi. 3:36

*Tropical rain forests, coral reefs, coasts, & islands have high biodiversity*~50% world’s species live in tropical rain forests

*25 spots on Earth are “Biodiversity hotspots” = have high #s of endemic species & are threatened*Endemic = found in a limited area; risk extinction

*The hotspots include places like Madagascar, the Caribbean, and tropical forests in South America, China, the Philippines, etc.

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*Examples of Endemic Species

Lemurs of Madagascar Rock macaque of Taiwan

Galapagos Tortoises Philippine Crocodile2:58

*Biodiversity Threats:*Endangered species = likely to go extinct in near future

*~10,000 animals worldwide are “endangered”

*Threatened species = populations are declining

Threats to Biodiversity:

1. Habitat fragmentation & destruction

(Ex: Florida panther almost went extinct)

2. Pollution

3. Overharvesting & Poaching (illegal hunting)

(Ex: fishing industries)

4. Invasive species (not native to a particular region; Ex: Fire ants, kudzu)

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*Preventing Biodiversity Loss: 1.Captive breeding: zoos, conservation groups

2. Endangered Species Act (1973) – law against hurting, trading, or destroying habitat of endangered species

3. IUCN (International Union for the Conservation of Nature and Natural Resources) – founded 1948; works to protect species & habitats worldwide

4.CITES (Convention on International Trade in Endangered species) – treaty pass in 1973 by 170 countries; controls trade of wildlife

5. National Parks & Wildlife Sanctuaries3:24