Future Large Scale Release of Carbon (Edexcel A Level Geography): Revision Note
Exam code: 9GE0
Future Emissions
Future Uncertainties
There are many uncertainties about future global warming and contributing natural and human factors
Uncertainty about natural factors include:
The role of carbon sinks and their capacity to cope with changes
Possible feedback mechanisms such as carbon release from peatlands and permafrost
Tipping points associated with forest dieback and the reversal of thermohaline circulation
Uncertainty about human factors include:
Future rates of global economic and population growth
Planned reduction in global carbon emissions
Exploitation of renewable energy sources
Natural Factors
Research has been conducted to see what the future changes to carbon stores may be with increasing carbon emissions
Future Changes to Carbon Stores
Terrestrial Carbon Sinks | Oceanic Carbon Sinks |
|---|---|
Modelled to increase until 2050 When saturation is reached, they begin to act as sources:
| Increased store in sea grasses and algae, but overall reduction as sink because:
|
Positive feedback from permafrost and peatlands
A positive feedback is a change that amplifies itself, making warming speed up
Permafrost is permanently frozen ground in the Arctic that stores huge amounts of frozen carbon
As the climate warms, the permafrost thaws
Microbes break down the thawed plant and animal matter, releasing carbon dioxide and methane
These gases trap more heat, causing more warming — which thaws even more permafrost
Methane matters because it is a far more powerful greenhouse gas than carbon dioxide — around 28–80 times stronger, depending on the timescale
Peatlands store carbon in waterlogged, partly decayed plant material
When they dry out or are drained, the peat decomposes and releases carbon dioxide
Warmer, drier conditions and peat fires speed this up, adding even more carbon to the atmosphere
Because each loop releases more greenhouse gas, these feedbacks make future warming harder to predict and control
Human Factors
The IPCC has identified key factors driving anthropogenic greenhouse gas emissions
The top five countries that emit carbon dioxide are China, the USA, India, Japan and Russia
China overtook the USA as a result of rapid urbanisation and industrialisation which indicates a positive relationship between economic growth and carbon emissions
Adaptation Strategies
Adaptation Strategies
Even if all carbon emissions stopped today, we would still have enhanced global warming due to past emissions and the length of time it takes for greenhouse gases to disperse from the atmosphere
There are two types of climate change adaptation strategies:
Hard strategies which require technology e.g., wind farms
Soft strategies which involve legislation e.g., land use zoning
All adaptation strategies have benefits and risks associated with them
Evaluation of Adaptation Strategies
Adaptation Strategy | Benefits | Risks |
|---|---|---|
Water conservation and management | Less resources used Less groundwater abstraction Changing attitudes e.g., use of more grey water | Efficiency and management cannot match any increases in demand for water Promotion and enforcement of strategies by the government needed to change habits e.g., smart meters |
Resilient agricultural systems | High-tech, drought-tolerant species help resistance to climate change and increased diseases Low-tech methods and better practices lead to healthier soils which may help carbon sequestration and water storage e.g., selective irrigation, crop rotation, agroforestry More ‘indoor’ intensive farming | Expensive technology, seeds and breeds unavailable to subsistence farmers in developing countries Indoor and intensive farming has high energy costs Genetic modification is still controversial but still used to create resistant strains of rich and soya Increasing food insecurity leads to countries looking for quick fixes |
Land-use planning | Land-use zoning, building restrictions in areas vulnerable to flooding Enforcing strict run-off controls and soakaways | Public dislike Abandoning high-risk areas is often impossible as they are often megacities Would need strong governance, enforcement and compensation |
Flood-risk management | Hard management often used e.g., river dredging, flood defences Simple changes can reduce flood risk e.g., permeable tarmac Reducing deforestation and increasing afforestation upstream to absorb water and reduce flood risk downstream | Funding sources are often debated Land owners will often demand compensation Constant maintenance is required for hard management e.g., dredging |
Mitigation Strategies
Mitigation Strategies
Mitigation strategies can help rebalance the carbon cycle
Rebalancing the carbon cycle is seen as vital in preserving the Earth’s life systems
The IPCC stated in 2014 that it was possible to keep within the target of no more than a 2°C increase in average global temperatures if:
Fossil fuel use was significantly reduced
Fossil fuel use was totally eliminated by 2100
The IPCC's later report, AR6 (2023), warned that the world is not on track to meet this target
Limiting warming to 1.5°C now requires rapid and deep emission cuts this decade
Global greenhouse gas emissions need to roughly halve by 2030 to keep 1.5°C within reach
Mitigation strategies are considered vital to staying within the 2°C increase
Mitigation strategies usually operate through five specific methods:
Carbon taxation
Renewable switching
Energy efficiency
Afforestation
Carbon capture and storage (CCS)
The UK has led the way with many of these strategies, but politics and austerity measures since 2011 have had an impact
The 2008 Climate Change Act established a 2050 target for the UK to reach Net Zero
This requires the UK to reduce emissions by at least 100% compared to 1990 levels
Mitigation Strategies Used in the UK
Mitigation Strategy | Examples of Policies in the UK |
|---|---|
Carbon taxation | Carbon price floor tax sets a minimum prices companies will have to pay to emit carbon dioxide which was unpopular and the policy was frozen in 2015 Lower road taxes for low-carbon cars were scrapped in 2015 In 2015, oil and gas exploration tax relief was expanded to support fossil fuels which led to the fracking debate |
Renewable switching | Renewable energy (solar, wind and wave) provide intermittent electricity, while fossil fuels provide continuous power which is vital for our current demands The Climate Change Levy, designed in 2001 to encourage investment in renewable energy was cut in 2015 |
Energy efficiency | The Green Deal scheme encouraged energy-saving improvements in homes e.g., energy efficient boilers and lights, improved insulation which was scrapped in 2015 Energy suppliers must comply with the Energy Company Obligation scheme to deliver energy efficient methods to households |
Afforestation | Tree planting in the UK is increasing which helps carbon sequestration Tree planting involves the Forestry Commission, charities (e.g., the National Trust and Woodland Trust), landowners and local authorities, The Big Tree Plant campaign encourages communities to plant 1 million new trees (mostly in urban areas) |
Carbon capture and storage (CCS) | Few actual geologic carbon capture and storage projects exist in the world, despite its potential Canada’s Boundary Dam is the only large-scale working scheme In 2015, the UK cancelled its investment into full-scale projects at gas and coal powered plants in Scotland and Yorkshire |
International mitigation strategies
International agreements
In 1988, the Intergovernmental Panel on Climate Change (IPCC) was set up to assess the 'risks of human-induced climate change
This was followed by several international agreements
Earth Summit, Rio 1992
Set out aims to stabilise greenhouse gas levels
Kyoto Protocol 1997
Delegates from 150 countries agreed to reduce greenhouse gas emissions
It stated that industrialised countries would reduce emissions to below the levels in 1990
Developing countries, including China and India, were exempt from the agreement
The USA did not sign up for the treaty
Canada withdrew in 2011, stating that without China and the USA, the treaty would not work
Paris Agreement 2015
Global agreement to limit global warming to 2 °C (preferably 1.5 °C) above pre-industrial levels
The agreement also includes reducing CO2 emissions by at least 60% by 2050
Signed by 196 countries, including the USA and China (the USA withdrew in 2020 and rejoined in 2021)
Conference of the Parties (COP)
The United Nations (UN) holds an annual (every year) meeting to discuss climate change.
COP29 in 2024 was held in Baku, Azerbaijan
All nations agreed to:
Agreed to provide at least $300 billion per year to developing countries by 2035
Take actions to further reduce greenhouse gas emissions
REDD
Reducing Emissions from Deforestation and forest Degradation (REDD) is a strategy launched by the UN
It aims to ensure the protection and sustainable management of forests
Funded by developed countries and transnational corporations to offset their carbon emissions
Solar radiation management
Geoengineering involves ideas and plans to intervene to counteract global warming
Idea to use orbiting satellites to reflect some radiation into space like a giant sunshade
The theory is that this would cool the Earth within months and be relatively cheap compared to other mitigation strategies
Differing attitudes to mitigation
Tackling climate change depends on the attitudes of different groups, and these often clash
Countries disagree over who should act
Developed countries caused most past emissions, so many argue they should make the biggest cuts and help fund poorer countries — an idea called common but differentiated responsibility
Emerging and developing countries argue they should not have to slow their growth to fix a problem they did little to cause
Transnational corporations (TNCs) are split
Some now set net zero targets and invest in renewable energy
Others lobby against tighter rules, or are accused of greenwashing — claiming to be greener than they really are
People also vary
Some change their lifestyles, such as flying less, eating less meat or switching to a green energy supplier
Others are unwilling or unable to change, often because greener choices cost more
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