1 / 29

Chapter 23

Chapter 23. Environmental Science. 23.1 Humans and the Environment. Environmental science is the study of the relationships between humans and the Earth Since all life is interconnected, it is important to develop ways to correct global problems from humans.

dickp
Download Presentation

Chapter 23

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 23 Environmental Science

  2. 23.1 Humans and the Environment • Environmental science is the study of the relationships between humans and the Earth • Since all life is interconnected, it is important to develop ways to correct global problems from humans

  3. A Global Connection • Warming and cooling air form loops called convection cells in Earth’s atmosphere • Convection cells determine climate and create oceanic circulation patterns

  4. The sun’s rays heat air molecules near Earth’s surface The less dense, warm molecules rise Eventually they cool and sink back toward Earth Convection Cells

  5. Upwelling • Cold water rises from the ocean depths and carries nutrients upward • More nutrients support more plankton which leads to large populations of fish

  6. El Nino • Occurs when the warm surface water prevents upwelling from occurring • Causes fish populations to decline (anchovy exports decrease)

  7. O3 is a naturally occurring gas that protects living things from harmful UV rays CFC’s are ozone-destroying chemicals Declining Ozone

  8. Chlorofluorocarbons • Used as coolants in refrigerators and air conditioners and as propellants • Banned in 1992 • As long as we don’t use CFC’s, the ozone layer will continue to recover

  9. Increasing CO2 • Carbon dioxide is a byproduct of cellular respiration and a component of photosynthesis • It is also released when fossil fuels are burned

  10. Greenhouse gases form a blanket around Earth and keep it at a temperature suitable for life When the layer gets thicker, it traps too much heat which causes global warming The Greenhouse Effect

  11. Evidence About Global Warming • Ice-core samples show there is a correlation between rising temperatures and CO2 concentrations • Global temperatures are expected to rise 2°C (4°F) within the next century • Can affect rainfall patterns, soil moisture, sea level, crop growth, biodiversity, human diseases, etc.

  12. Future Population Growth • The U.N. estimates that human population will be at 12.5 billion by 2050 • This would result in more fossil fuels being burned and higher global temperatures

  13. 23.2 The Biodiversity Crisis • Biodiversity: the variety of organisms in a given area • Genetic diversity: the amount of genetic variation (the most important measure of biodiversity)

  14. Measuring Biodiversity • There are 3 million species that have been identified on Earth • It is estimated that there are 10-30 million species • Tropical rainforests have many undiscovered species

  15. Earth’s Biodiversity

  16. Extinction • Extinction is forever! • Rapid destruction of habitats is driving many species to extinction each day • More than half of all tropical rainforests have already been destroyed

  17. Ways to Save Biodiversity • Conservation strategies! (Ecotourism) • Debt-for-nature swap: richer countries or private organizations pay off some of the debts of a developing country in exchange for them not cutting down their rainforest

  18. The Importance of Biodiversity • Utilitarian Value: considers the economic benefits that biodiversity provides for humans (food, medicine, etc.) • Nonutilitarian Value: All life-forms deserve to exist (intrinsic value) • Need for a “Declaration of Interdependence”

  19. Conservation and Restoration Biology • Conservation biology: identify and maintain natural areas to preserve biodiversity • Restoration biology: convert damaged areas back into viable habitats

  20. Conserving Migratory Birds • Migratory birds spend spring and summer in Tundra and northern forests (abundant insects for food) • In the Fall, they migrate to warmer climates where there will be enough food to last until their next breeding season

  21. Flyways • There are four major flyways in North America

  22. Saving Critical Habitat • Wildlife refuges must be established along the flyways to allow birds a place to rest and eat during their long migrations • They also need protection in their wintering grounds • Conservation efforts need to be international!

  23. Magee Marsh

  24. Reintroduction of the Wolf • The gray wolf is an endangered species because they were killed by people • There has never been a documented case of a human being attacked by a healthy wolf! • They will occasionally kill livestock

  25. Without wolves in the park, the elk population exploded In 1995, 14 wolves were released Wolves in Yellowstone

  26. Drainage canals were built to divert water away from the everglades so people could use the land for homes More than 50% of the wetland was destroyed The Florida Everglades

  27. Wetlands • Wetlands are important habitats for wildlife • They also purify drinking water and help replenish groundwater • Coastal wetlands prevent flooding and beach erosion

  28. Everglades Restoration • Currently, a restoration plan is being implemented to remove some of the drainage canals • 40,000 hectares (100,000 acres) will be set aside for protection • Melaleuca trees will be cut down (non-native species)

  29. Get Involved! • Learn about your local environment • Get involved in your own community to preserve local biodiversity • Recycle • Urban ecology: increasing biodiversity in heavily developed areas

More Related