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ENVIRONMENTAL PROBLEMS

BIODIVERSITY LOSS
Biodiversity - refers to the number and size of populations in a community; variability of species in an area

In general, there are three categorical levels of biodiversity: 1. Genetic biodiversity
- involves populations, individuals, chromosomes, genes and nucleotides

2. Taxonomic biodiversity
- include kingdoms, phyla, orders, families, genera, species, subspecies and populations - for practical reasons, the most commonly used taxonomic diversity measure is species diversity, or alpha diversity which is also called species richness and is simply the number of species in a given area

3. Ecological biodiversity
- refers to the diversity of habitats on which individuals within a species depend on for their own unique niches that they occupy within the ecosystem. Niche – role of an organism in its ecosystem

Megadiverse countries
- the 17 countries which harbor 60 to 70% of species in the world - a group of countries in which less than the 10% of the global surface has more than the 70% of the biodiversity - most of these countries are located in the tropics

Hotspots
- British biologist Norman Myers coined the term "biodiversity hotspot" in 1988 as a biogeographic region characterized both by exceptional levels of plant endemism and by serious levels of habitat loss

Causes of biodiversity loss:
1. deforestation
2. exploitation by humans
3. habitat destruction
4. pollution
5. natural catastrophes

Threats to biodiversity:
1. becoming threatened
A species that is facing an extremely high risk of extinction in the wild in the immediate (critically endangered), near (endangered) or medium-term (vulnerable) future.

2. becoming extinct
- extinct species: species not located in the wild in the last 50 years

GLOBAL WARMING

Global warming - an average increase in the temperature of the atmosphere near the Earth's surface and in the troposphere which can contribute to changes in global climate patterns - can occur from a variety of causes, both natural and human induced - the term climate change is often used interchangeably with the term global warming, but according to the National Academy of Sciences, "the phrase 'climate change' is growing in preferred use to 'global warming' because it helps convey that there are [other] changes in addition to rising temperatures”

Causes:
A. Greenhouse Gases
1. Carbon dioxide – enters the atmosphere through burning of fossil fuels 2. Methane – emitted during the production and transport of coal, natural gas and oil 3. Nitrous Oxide – emitted during agricultural and industrial activities, and combustion of fossil fuels and waste 4. Fluorinated gases – referred to as High Global Warming Potential Gases (High GWP Gases) - e.g. hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride - synthetic powerful greenhouse gases that are emitted from a variety of industrial processes

B. Sun’s radiation
- fluctuations of the sun’s radiation add to global warming - effects are twenty times weaker than human-induced warming

C. Feedback: Atmosphere hold more water vapor
- water acts as greenhouse gas

Effects:
1. glacial retreat
2. Arctic shrinkage
3. sea temperature and sea level rise
4. extreme weather events
5. displacement of flora (plants) and fauna (animals)

Future Scenario - called A1B
- a world of very rapid economic growth with a population that peaks around mid-century and declines thereafter - new and more efficient technologies are introduced rapidly - regional differences in per capita income diminish.

- energy comes from a number of well-balanced sources

Kyoto Protocol - protocol to the International Framework on Climate Change with the objective of reducing...
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