This lesson reviews how we can classify different threats to the biosphere and some of the more subtle environmental degradation (break down or deteriorate) occurring.
Classifications:-
Root Cause: the fundamental reason for the problem e.g. Poverty, National Debt, increased standard of living, economic development, population growth.
Immediate Cause: the actual actions that result in the damage. e.g. logging, tourism, alien species, cattle farming
Direct Threat: Immediate human actions e.g. Deforestation, Mining, Quarrying, Farming,Overfishing, Introduction of an alien species.
Indirect Threat: More long term problems such as Climate change and pollution. Whilst most of these are impacted by humans some can be completely natural. e.g. sea temperature rise, seawater acidification, melting of polar ice caps, changing weather patterns. (NOTE – I have been more specific than just saying global warming).
There is a significant amount of cross other within these different categories. When reviewing the following descriptions of various indirect threats it is worth keeping in mind the scale of the threat and who is to blame? Is it simply a local issue or is there more of an international cause to the threat?
Expanding Population / Economic Development /Standards of Living
With an ever increasing population there is more demand for food, water, land, jobs, energy, etc.. These resources all greatly impact the biosphere reducing the biodiversity. As less developed counties continue to develop they are demanding more and more from the environment. Two of the best examples for this is the increase in electrical demand. As countries grow more wealthy items we take for granted become affordable. Inevitably these require electricity such as computers, televisions, microwave ovens, refrigerators.
This means governments have to provide more and more electricity to the growing populations. This is mostly done through the burning of fossil fuel which pollutes the environment and even more green options such as Hydro electric power (H.E.P) have their critiques such as the Belo Monte dam.
These root causes are all very complex intertwined and in many ways understandable.
- It is fair to tell countries they must not develop as it is impacting the environment?
- Are you willing to reduce your electrical consumption?
Indirect Threats
Global Warming (Climate Change)
- This is the biggest indirect threat affecting the whole biosphere.
- Currently vegetation zones (biomes) are moving toward the poles at a rate of 6km every 10years.
- Whilst climate change is a natural occurrence, Anthropogenic change is causing such rapid rise that species are unable to adapt. (Anthropogenic = Man made)
- A rise of 3°C is predicted by some scientist by 2060. If this is the case 20-50% of all land species face extinction!
- An estimated 20–30% of the carbon dioxide released by humans into the atmosphere dissolves into the Oceans.
- Dissolving CO2 in seawater increases the hydrogen ion (H+) concentration in the ocean, and thus increases the acidity.
- This has a huge impacts of the ocean biomes particularly Coral reefs and usually the Key Stone species of the food chain (Key Stone Species = A species whose presence and role within an ecosystem has a disproportionate effect on other organisms within the system e.g. plankton )
- This threat greatly impacts the tourism and fisheries industries (particularly in the tundra).
- Climate change (linked to global warming) is having a big impact on global weather patterns
- Melting ice caps are changing the thermohaline circulation (these are deep ocean currents that circulation warm and cold water around the globe.)http://www.youtube.com/watch?v=dSUImcuK-Ps
- Changes in the thermohaline circulation change global weather patterns but the full extent of the THC influence on global weather patterns is still to some extent under discussion!
- The Amazon is experiencing an increasing number of droughts and the Sahara is growing at its fastest ever rate (due to shifting air masses so less rain)
