Human impact on the environment

One of two core boundaries. Enough greenhouse gases have been added to our atmosphere, that if we stopped adding gases to our atmosphere the temperarture would keep on rising.

Status:At Risk

Solution: Biofuels

Growing more biofuel crops removes carbon dioxide from the atmosphere. These biofuels are also made by biological proceses such as anaerobic digestion of plant material or agricultural, domestic and industrial waste.

Bioethanol is produced from starch or a sugar crop when it is crushed. The bagasse fibrous waste is used to distill ethanol into pure ethanol. Biodiesel is made from vegetable oils and algae. Methanol + linoleic acid = methyl linoleate + water. It contains less carbon more hydrogen and oxygen. Produces 60% of carbon emissions, and produces nitrous oxide. Biogas is made by bacterial digestion of biodegradable waste. It has three stages, digestion, acetogenesis and methanogenesis.

Second of two core boundaries. It concerns the human impact on the ecosystem.

Status:High Risk

Solution: Taking in material for gene banks. Publicity to increase awareness of habitat loss to reduce human behaviour that has led to biodiversity loss.

Habitat change is seen worldwide - By 2100 without any of the changes more than half of the 200,000 marine species may become extinct. This is due to pollution of the oceans by sewage.

Tundra ecosystems are altering as the temperature rises and species including herbaceous plants grow where in the past only lichens and mosses were seen,

Coral reefs are being damaged.

Concerns the usage of land for biofuel crops. Food vs fuel debate.

Status: At risk

Solution: Farming should be concentrated in more productive areas. A global reduction in meat comsumption and genetically modified plants.

Refers to the cycling of minerals through the biotic and abiotic components of an ecosystem such as the carbon, nitrogen, sulphur and phosphorus cycles.

Status: At risk

Solution:Need to reduce the usage of fertilisers. Ths can be done by adding nitrogen fixing genes to plants but so far it has not been possible.

Human activity have disrupted the cycles of these minerals so much that they are no-longer self sustaining. 

90% ozone in the stratosphere. Ozone and oxygen would normally be at equilibrium with each other.

Haloganted hydrocarbons such as the chloro-fluorocarbons (CFCs) alter the position of the equilibrium and favour the breakdown of ozone. Less ozone would mean more of the Sun's ultraviolet light would be able to enter the Earth's surface causing harmful effects to its inhabitants.

Status:Safe

Solution: Banned usage of CFCs in 1978, the Montreal protocols banned the manafacture of CFCs on nation states.

In the 17th century, the pH of the oceans was 8.16, now it has changed to 8.03.

Carbon dioxide from the air dissolves in water to form hydrogen carbonate which then dissolves into carbonate ions and hydrogen ions. The hydrogen ions will decrease the pH.

Low pH causes the leaching of calcium carbonate out of molluscs, coral shells and arthropod exoskeletons making them vulnearable to physical and chemica attacks.

Status: Safe

Solution: A reduction in overall fossil fuel combustion may prevent the oceans udergoing catastrophic pH change.

Liquid water is critical for the survival of living organisms so this boundary concerns the usage of the water on Earth.  97% of the water on the Earth is saline and only 2.5% is fresh water.

Fresh water has decreased due to changing landscapes, agriculture, increased demand in hotter climates, water pollution, climate change, increase in population and increase in its general usage.

Status: Safe

Solution: There are many solutions to efficient water usage such as water conservation that is to save water on non-food crops. Water efficiency and reclamation. Urban runoffs to catch storm water before it reaches the ground and becomes saline.

Drip irrigation systems to reduce water volume and desalination to remove minerals from salt water.

There are numerous methods for which desalination can be done - through either solar stills to distill seawater using heat from the sun or reverse osmosis. The process of reverse osmosis is to use an external pressure to push water up a water potential gradient.

Concerns the atmospheric aerosols in the atmosphere by combustion of fuels.

These microscopic particles can exacerbate respiratory problems causing deaths from lung disease. Can also reduce the light absorption for photosynthesis in plants and sulphates in aerosols reflect sunlight or absorb it increasing the temperature.

Status: Not quantified

Increasing use of new technologies and materials has led to this boundary being created. It includes the usage of radioactive materials, nanomaterials and micro-plastics.

Status: Not quantified

Solution: Banned usage of chemiclas such as DDT and PCBs