Global threats to biodiversity

Global Warming
1. Oceans
  1. The Coral Triangle
    1. Climate change in the Coral Triangle is already having a big impact on coastal ecosystems by warming, acidifying and rising seas. Coral Triangle reefs have experienced severe mass coral bleaching and mortality events as temperatures have periodically soared.
    2. The annual, maximum and minimum temperatures of the oceans surrounding the coastal areas of the Coral Triangle are warming significantly (0.09-0.12 ° C per decade) and are projected to increase by 1-4°C toward the end of this century.
      1. Increases of more than 2°C will eliminate most coral-dominated reef systems.
    3. 120 million: people directly sustained by the marine and coastal resources of the Coral Triangle.
    4. US$2.4 billion: sustainable fisheries benefit for all of Southeast Asia from coral reefs.
    5. US$12 billion: size of the Coral Triangle nature-based tourism industry.
    6. 30% of the global tuna catch, and a lucrative trade in live reef fish for food markets, which is worth nearly $1bn (£655m).
  2. Acidic seas will drive reef collapse
  3. Longer and more intense floods and droughts
  4. Sea level rise of 0.5, 1.0 or 6 metres
  5. More intense cyclones and typhoons
  6. The 1997-98 El Niño weather event triggered the largest worldwide coral bleaching event ever recorded. In Southeast Asia, an estimated 18% of the region's coral reefs were damaged or destroyed.
2. Shifts in climate zones will stress biomes; migration patterns will be altered; some biomes (tundra, montane forest) may be wiped out.
3. Loss of habitats such as melting Arctic Ice resulting in the loss of some species such as the polar bear.
Desertification
1. A widespread and complex problem, some 10-20% of dryland ecosystems are already degraded; grasslands are very vulnerable.
2. Causes
  1. Policies leading to an unsustainable use of resources and the lack of adequate infrastructures are major contributors to land degradation.
  2. People farming by containing their livestock, such as cattle, in fenced areas results in overgrazing.
  3. Farmers are clearing average land, and using it which takes away the richness in the soil.
    1. Disrupts the nutrient cycle.
  4. People are cutting down tress to use them as a source of fuel. Once all these trees are cut down there is nothing to protect the soil. Therefore, it turns to dust and is blown away by the wind.
  5. Incorrect irrigation is commonly used in poorer areas. Farmers are using canal irrigation and other poor techniques because of the lack of water. This type of irrigation causes a build up of salt in the soil.
3. Impacts
  1. The soil can be blown away by wind or washed away rain. Nutrients in the soil can be removed by wind or water. Salt can build up in the soil which makes it harder for plant growth.
  2. Loosened soil may bury plants or leave their roots exposed. Also, when overgrazing occurs, plant species may be lost.
  3. Places that have war and poverty are most likely to have famine occur. Drought and poor land management contribute to famine.
  4. Desertification can cause flooding, poor water quality, dust storms, and pollution. All of these effects can hurt people living near an affected region.
4. The Sahel
  1. Around the 1950’s, people settled into the Sahel region, in areas where there was water. This resulted in overgrazing.
    1. A lot of the topsoil was washed away, and all that was left were rocks. Silt turned hard when it was hit by rain. Therefore, plants were not able to grow because there roots could not penetrate this hard layer.
      1. Records show that rainfall in Sahel has decreased and sands have shifted about sixty miles south into the area. Sahel is expanding due to lack of vegetation in the area.
        Another reason desertification is occurring in the Sahel region is because people are using the slashing and burning method to clear land. This degrades the quality of soil just like overgrazing.
  2. Impacts
    1. Long term
      1. People die of starvation
      2. Cattle die of starvation
      3. The soil becomes completely useless
    2. Short term
      1. Soil loses its nutrients which makes it not useful
      2. Overgrazing destroys vegetation and without it erosion occurs
      3. Land becomes salty which makes it difficult to grow crops.
Poverty and Food insecurity.
1. Poverty
  1. Poor countries cannot afford to use advanced methods of harvesting ecosystems resulting in unnecessary damage.
  2. The livelihoods of more than one billion people depend directly on natural resources.
    1. Results in over use
  3. Lack of enforcement to protect biodiversity.
    1. The Amazon is an example of an ecosystem which is too expensive for the local enforcement groups to protect.
  4. Inability to fund conservation especially for endemic species.
  5. High population of subsistence farmers.
2. Food insecurity
  1. People over harvesting the ecosystems resulting in loss of species.
  2. Land used for agriculture, usually only one type of crop, low biodiversity.
  3. Big areas destroyed for farming.
    1. e.g. Cattle farming in the Amazon

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Global threats to biodiversity

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	Creado por Jason Edwards-Suarez hace alrededor de 9 años