The 2014 IPCC report stated that anthropogenic emissions of greenhouse gases have led to unprecedented levels of carbon dioxide, methane and nitrous oxide in the environment. The report also stated that the effect of greenhouse gases is extremely likely to have caused the global warming we have witnessed since the 20th century.
The 2018 IPCC report set new targets, aiming to limit climate change to a maximum of 1.5°C. To reach this, we will need zero CO₂ emissions by the year 2050. Previous IPCC targets of 2°C change allowed us until roughly 2070 to reach zero emissions. This means government policies will have to be reassessed and current progress reviewed in order to confirm whether or not the UK is capable of reaching zero emissions by 2050 on our current plan.
Electricity Generation
Fossil fuels are natural fuels formed from the remains of prehistoric plant and animal life. Fossil fuels (coal, oil and gas) are crucial in any look at climate change as when burned they release both carbon dioxide (a greenhouse gas) and energy. Hence, in order to reach the IPCC targets the UK needs to drastically reduce its usage of fossil fuels, either through improving efficiency or by using other methods of energy generation.
Whilst coal is a cheap energy source used to generate approximately 40% of the world’s electricity , it’s arguably the most damaging to the environment as coal releases more energy into the atmosphere in relation to energy produced than any other fuel source. Coal power stations generate electricity by burning coal in a combustion chamber and using the heat energy to transform water to steam which turns the propeller-like blades within the turbine. A generator (consisting of tightly-wound metal coils) is mounted at one end of the turbine and when rotated at a high velocity through a magnetic field, generates electricity. However the UK has made great claims to fully eradiate the use of coal in electricity generation by 2025. These claims are well substantiated by the UK’s rapid decline in coal use. In 2015 coal accounted for 22% of electricity generated in the UK, this was down to only 2% by the second quarter of 2017 and in April 2018 the UK even managed to go 72 hours powered without coal.
Natural gas became a staple of British electrical generation in the 1990s, when the Conservative Party got into power and privatised the electrical supply industry. The “Dash for gas” was triggered by legal changes within the UK and EU allowing for greater freedom to use gas in electricity generation.
Whilst natural gas emits less CO₂ than coal, it emits far more methane. Methane doesn’t remain in the atmosphere as long but it traps heat to a far greater extent. According to the World Energy Council methane emissions trap 25 times more heat than CO₂ over a 100 year timeframe.
Natural gas produces electrical energy in a gas turbine. Natural gas is mixed with the hot air and burned in a combustor. The hot gas then pushes turbine blades and as in coal plant, the turbine is attached to a generator, creating electricity. Gas turbines are hugely popular as they are a cheap source of energy generation and they can quickly be powered up to respond to surges in electrical demand.
Combined Cycle Gas Turbines (CCGT) are an even better source of electrical generation. Whilst traditional gas turbines are cheap and fast-reacting, they only have an efficiency of approximately 30%. Combined cycle turbines, however, are gas turbines used in combination with steam turbines giving an efficiency of between 50 and 60%. The hot exhaust from the gas turbine is used to create steam which rotates turbine blades and a generator in a steam turbine. This allows for greater thermal efficiency.
Nuclear energy is a potential way forward as no CO₂ is emitted by Nuclear power plants. Nuclear plants aim to capture the energy released by atoms undergoing nuclear fission. In nuclear fission, nuclei absorb neutrons as they collide thus making an unstable nucleus. The unstable nucleus will then split into fission products of smaller mass and emit two or three high speed neutrons which can then collide with more nuclei, making them unstable thus creating a chain reaction. The heat energy produced by splitting the atom is first converted can be used to produce steam which will be used by a turbine generator to produce electricity.
Currently, 21% of electricity generated in the UK comes from nuclear energy. In the 1990s, 25% of electricity came from nuclear energy but gradually old plants have been retired. By 2025, UK nuclear power could half. This is due to a multitude of reasons. Firstly, nuclear fuel is expensive in comparison to gas and coal. Secondly, nuclear waste is extremely radioactive and so must be dealt with properly. Also, in light of tragedies such as Chernobyl and Fukushima, much of the British public expressed concerns surrounding Nuclear energy with the Scottish government refusing to open more plants
In order to lower our CO₂ emissions it is crucial we also utilise renewable energy. The UK currently gets very little of its energy from renewable sources but almost all future plans place a huge emphasis on renewables.
The UK has great wind energy potential as the nation is the windiest country in the EU with 40% of the total wind that blows across the EU.
Wind turbines are straightforward machinery; the wind turns the turbine blades around a rotor which is connected to the main shaft which spins a generator, creating electricity. In 2017, onshore wind generated enough energy to power 7.25 million homes a year and generated 9% of the UK’s electricity. However, despite the clear benefits of clean, renewable energy, wind energy is not without its problems. Firstly, it is an intermittent supply – the turbine will not generate energy when there is no wind. Also it has been opposed by members of the public for affecting the look of the countryside and bird fatalities. These problems are magnified by the current conservative government’s stance on wind energy who wish to limit onshore wind farm development despite public opposition to this “ban”.
Heating and Transport
Currently it is estimated a third of carbon dioxide (CO2) emissions in the UK are accounted for in the heating sector. 50% of all heat emissions in the UK exist for domestic use, consequently making it the main source of CO2 emissions in the heating sector. Around 98% of domestic heating is used for space and water heating. The government has sought to reduce the emissions from domestic heating alone by issuing a series of regulations on new boilers. Regulations state as of 1st April 2005 all new installations and replacements of boilers are required to be condensing boilers. As well as CO2 emissions being much lower, condensing boilers are around 15-30% more efficient than older gas boilers. Reducing heat demand has also been an approach taken to reduce emissions. For instance, building standards in the UK have set higher levels of required thermal insulations of both domestic and non-domestic buildings when refurbishing and carrying out new projects. These policies are key to ensure that both homes are buildings in industry are as efficient as possible when it comes to conserving heat.
Although progress is being made in terms of improving current CO2 reducing systems, the potential for significant CO2 reductions rely upon low carbon technologies. Highly efficient technologies such as the residential heat pump and biomass boilers have the potential to be carbon neutral sources of heat and in doing so could massively reduce CO2 emissions for domestic use . However, finding the best route to a decarbonised future in the heating industry relies upon more than just which technology has the lowest carbon footprint. For instance, intermittent technologies such as solar thermal collectors cannot provide a sufficient level of heat in the winter and require a back-up source of heat making them a less desirable source of heat . Cost is also a major factor in consumer preference. For most consumers, a boiler is the cheapest option for heating. This provides a problem for low carbon technologies which tend to have significantly higher upfront costs . In response to the cost associated with these technologies, the government has introduced policies such as the ‘Renewable Heat Incentive’ which aims to alleviate the expense through paying consumers for each unit of heat produced by low carbon technologies. Around 30% of the heating sector is allocated for industry use, making it the second largest cause of CO2 in this sector . Currently, combined heat and power (CHP) is the main process used to make industrial heat use more efficient and has shown CO2 reductions of up to 30%. Although this is a substantial reduction in CO2, alternative technology has the potential to deliver even higher reductions. For example, the process of carbon capture storage (CCS), has the potential to reduce CO2 emissions by up to 90% . However, CCS is a complex procedure which would require a substantial amount of funding and as a result is not currently implemented for industrial use in the UK.
Although heating is a significant contribution to CO2 emissions in the UK, there is also much needed progress elsewhere. In 2017 it was estimated that 34% of all carbon dioxide (CO2) emissions in the UK were caused by transport and is widely thought to be the sector in which least progress is being made, with only seeing a 2% reduction in CO2 emissions since 1990. Road transport contributes the highest proportion of emissions, more specifically petrol and diesel cars. Despite average CO2 emissions of new vehicles declining, the carbon footprint of the transport industry continues to increase due to the larger number of vehicles in the UK.
In terms of progress, CO2 emissions of new cars in 2017 were estimated to be 33.1% lower than the early 2000s. Although efficiencies are improving, more must be done if we are to conform to the targets set from the Climate Change Act 2008. A combination of decarbonising transport and implementing government legislation is vital to have the potential to meet these demands. New technology such as battery electric vehicles (BEV’s) have the potential to create significant reductions in the transport industry. As a result, a report from the committee of climate change suggests that 60% of all sales of new cars and vans should be ultra-low emission by 2030. However, the likeliness of achieving this is hindered by the constraints of new technologies. For instance, low emission vehicles are likely to have significantly higher costs and lack consumer awareness. This reinforces the need of government support in projecting new technologies and cleaner fuels. To support the development and uptake of low carbon vehicles the government has committed £32 million for the funding of charging infrastructure of BEV’s from 2015-2020 and a further £140 million has been allocated to the ‘low carbon vehicle innovation platform’ which strives to advance the development and research of low emission vehicles. Progress has also been made to make these vehicles more cost competitive through being exempt from taxes such as Vehicle Excise Duty and providing incentives such as plug in grants of up to £3,500. Aside from passenger cars, improvements are also being made to emissions of public transport. The average low emission bus in London could reduce its CO2 emissions by up to 26 tonnes per year subsequently acquiring the governments support in England of the ‘Green Bus Fund’.
Conclusion
In 2017, renewables accounted for a record 29.3% of the UK’s energy generation. This is a vast improvement on previous years and suggests the UK is on track to meet the new IPCC targets although a lot of work still needs to be done. Government policies do need to be reassessed in light of the new targets however. Scotland should reassess its nuclear policy as this might be a necessary stepping stone in reduced emissions until renewables are able to fully power the nation and the UK government needs to reassess its allocation of funding as investment in clean energy is on a current downward trajectory.
Although progress has been made to reduce CO2 emissions in the heat and transport sector, emissions throughout the UK remain much higher than desired. The committee of climate change report to parliament (2015), calls for the widespread electrification of heating and transport by 2030 to help prevent a 1.5 degree rise in global temperature. This is likely to pose as a major challenge and will require a significant increase in electricity generation capacities in conjunction with greater policy intervention to encourage the uptake of low carbon technologies. Although the likelihood of all consumers switching to alternative technologies are sparse, if the government continues to tighten regulations surrounding fossil fuelled technologies whilst the heat and transport industry continue to develop old and new systems to become more efficient this should see significant CO2 reductions in the future.
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