Future Uncertainty

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Factors to Uncertainty

Climate change is uncertain due to a large number of factors and feedback mechanisms that may increase or stabilise the current impacts.

Natural factors

How oceans will respond to the upcoming changes in climate is uncertain.
Sea surface temperatures might rise, leading to increased likelihood and intensity of tropical storms.
Increased glacial melt will increase sea level rise.
Increases in atmospheric carbon will cause the ocean to become more acidic, leading to problems with coral and other organisms.

Human factors

The resources and energy available to us in the future depends on many factors.
- E.g. Population growth, economic development and technological developments that may support the challenges for resources we currently have.
Economic growth is frequently linked to carbon emissions, especially in developing nations where deforestation is occurring for land-use change e.g. mining and farming.
Emerging nations may still have high rates of fossil fuel consumption to support their secondary and tertiary industry progression.

Human factors 2

Population growth leads to many more middle-class consumers. These consumers want all the resources that are expected in affluent middle class communities.
This can be seen in the shift to a more meat and fat-based diet in China.
Energy consumption is likely to increase with population and economic growth. There is uncertainty over how much of this will be covered by renewable energy.

Feedback mechanisms are where something that happens in a system has a knock-on effect on the rest of the system. For example, if Arctic ice melts, sea temperature and levels rise. The sea being warmer feeds back and makes more Arctic ice melt.

Peat

Peat is a soil formed from vegetation that is partly decayed.
As a result of the low decomposition, this soil contains high amounts of carbon.
If peat dries out, the water table drops. But the decomposition rates also increase, leading to more carbon emission release.
The peatlands also emit methane, which contributes to the greenhouse gases.

Saddleworth Moor wildfire

Dry weather in June 2018 in Manchester, UK led to wildfires on Saddleworth Moor.
The wildfires were hard to contain because the dry bushes were on peat, which is extremely flammable.
The wildfire resulted in 40 homes being evacuated.

Permafrost

As permafrost thaws, CO₂ and methane are released.
This contributes to greenhouse gases and enhances the greenhouse effect, which results in further increases in temperature.
Increasing temperature leads to further melting of the permafrost and emission of more greenhouse gases.

Tipping Points

Tipping points in any system are points where there will be a drastic, sometimes irreversible change.

Forest dieback

If drought in rainforests causes enough trees to die, then a tipping point can be reached.
At the tipping point, there is so much dead vegetation that any rainfall doesn't infiltrate. As there is no evapotranspiration (water evaporating off plants) happening, overall rainfall is also reduced.
This leads to further vegetation dying because of the further reduced rainfall.

The thermohaline circulation

Increased melting of northern glaciers and ice caps would result in large amounts of non-salty, less dense water entering into the oceans.
This would disturb the conveyor belt of hot water moving from the tropics to the cold water from the poles.
The change in the thermohaline system may result in cooling of temperatures in the Northern Hemisphere.