Net Zero

The UK government’s climate change policies commit the UK to reach ‘net zero’ greenhouse gas emissions by 2050, but what is meant by net zero?

Download this article as a pdf Net Zero

Net zero means that the total amount of greenhouse gases produced by the UK will be equal to the amount of greenhouse gases removed from the atmosphere, by natural or manmade processes, with the aim of limiting global warming and climate change. We will no longer be adding to the amount of greenhouse gases in the atmosphere. It does not mean we will stop producing all greenhouse gas emissions, which in some areas such as food production is not possible, but the greenhouse gas emissions we produce will be cancelled out by their removal elsewhere. The net zero target for the UK is to reduce its greenhouse gas emissions by 100% from 1990 levels by 2050. The Climate Change Act (2008) originally set a target of 80% but this was increased to 100% in 2019. The cuts in greenhouse gas emissions need to be permanent, meaning the removed greenhouse gases do not return to the atmosphere in the future. Also, the reduction in greenhouse gas emissions is cumulative and reductions are needed from now on to reach net zero by 2050. Any increases now will require larger reductions in the future. We will achieve net zero by both reducing our emissions and implementing methods for the removal of greenhouse gases from the atmosphere.

The UK government has adopted a suite of policies to reach net zero and these are set out in two strategy publications; the ‘Net Zero Strategy’ (2021) and ‘Powering up Britain: The Net Zero Growth Plan’ (2023).

So how are we doing in the UK towards achieving this target? In terms of reducing our greenhouse gas emissions, domestic emissions in the UK have roughly halved since 1970. Some of this reduction is because the manufacture of goods that produce a lot of greenhouse gases has moved to outside of the UK and the goods are then imported back into this country. However even allowing for this change there has still been a significant decline in our emissions. These so-called consumption-based emissions, which takes into account the move in production, have declined significantly in many countries and most, including the UK, have still grown their economies at the same time. So action taken to reduce greenhouse gases does not mean the economy will not grow.

The UK’s Climate Change Committee monitors the legal requirements of the Climate Change Act for the government. In 2023, the committee reported on the various sectors of the economy and how they were doing in reducing greenhouse gas emissions. The main sectors of the economy are surface transport (road and rail – 23%); energy (electricity and fuel supply – 18%); heat and buildings (17%); industry (14%); agriculture and land use (11%). The figures in brackets refer to the percentage of total greenhouse gas emissions produced by each sector. In some areas the UK has performed well. For example, for energy, specifically electricity production, there has been significant progress in using alternative means of producing electricity. In 2023 wind and solar combined accounted for 33% of our total electricity generation. In 1990 wind power contributed just 0.01 terawatt hours (TWh) of our electricity generation but by 2023 this had increased to 82.46 TWh. Similarly the amount of electricity produced by solar power has gone from zero to 13.51 TWh during the same time. For comparison the amount of electricity produced using gas was 100.52 TWh in 2023. However two sectors show the progress in reducing emissions has stalled. These are heat and buildings, where the report says there have been ‘no significant reductions in emissions since 2010’, and in agriculture and land use, where it says ‘methane emissions from agriculture (just under half of UK methane emissions) have remained stable since 2008.’ Therefore significant changes are still required in these areas.

The other method of reducing greenhouse gases is their removal from the atmosphere. Most of the current effort in this area concerns the removal and storage of carbon dioxide and currently nearly all this removal is due to afforestation and reforestation, in other words planting trees. Very small amounts of carbon dioxide are removed by other newer methods. These newer methods include bioenergy with carbon capture and storage (BECCS), where biomass (organic matter, mostly from plants) is used for energy production and then the carbon dioxide is captured and stored underground. Another method is direct air capture and storage (DACCS), which uses engineering processes to capture the carbon dioxide for geological storage. Currently most countries’ plans for the removal and storage of carbon dioxide are much less than what is needed to keep global warming to below 2°C, and a very large increase is also needed from afforestation and reforestation to achieve this target.

In summary, we have made some significant progress in the UK towards achieving net zero by 2050 but more work is needed, now and in the future, if we are to achieve this.

What can we do as individuals? It is not possible for us to remove our own personal emissions from the atmosphere and so our actions need to be on reducing our emissions. This will be covered by another article in a future edition of The Cottage.