Net Zero: Frequently Asked Questions

The scientific evidence is clear: to avoid the worst climate impacts, the world needs to reduce its greenhouse gas emissions. The largest contributor is carbon dioxide (CO2), emitted when fossil fuels are burnt to meet our demand for energy. Through the Paris Agreement, governments committed to keeping global warning below 2 degrees Celsius and make further efforts for keep it below 1.5 degrees Celsius. Becoming net zero is necessary in order to meet these commitments. By reducing emissions produced in the UK to zero, it will end the country’s contribution to rising global temperatures.

The UK has set a legally binding target to cut its greenhouse gas emissions to net zero by 2050. It is one of the most ambitious in the world and the UK was the first major global economy to legislate for net zero. The target will require the UK to bring all greenhouse gas emissions to net zero by 2050, compared with the previous target of at least 80% reduction from 1990 levels.

A gross zero target would reduce emissions from all sources uniformly to zero. In contrast, net-zero is more realistic because it allows for some residual emissions, particularly from industries where it would be too complex to achieve this or there are cost implications. In this scenario, emissions are allowed but must be offset by removing emissions in other ways.

Reaching net zero requires us to transition our energy supply away from fossil fuels and onto renewables and other low carbon sources. We also need to reduce our energy demand across all sectors including household, industry, manufacturing and agriculture – for example, by becoming more energy efficient and changing our behaviour. The remaining greenhouse gases need to be balanced out through carbon removal. This could be achieved through forest restoration or technology such as carbon capture and storage.

The Committee on Climate Change’s most recent report to Parliament (July 2019) on net zero progress says that ‘actions to date have fallen short of what is needed for the previous targets and well short of those required for the net-zero target.’ Since then, the government has made a number of wide reaching announcements to support green growth and limit CO2 emissions – such as bringing forward the ban on the sale of petrol and diesel cars. Further announcements were made in the 2020 budget – you can read about those here.

This is complex – and the Committee on Climate Change has analysed the costs and benefits in detail. But most major economies agree that a global shift to net zero will help to avoid significant costs - including climate damage and climate adaptation. The Committee on Climate Change concludes: “economies which have integrated decarbonisation into other policy aims will have generated growth, for example by improving energy efficiency, reducing productivity losses from particulate pollution and congestion and attracting skilled workers to cleaner, more sustainable and technologically advanced cities. The potential magnitude of these benefits should not be underestimated.” The UK government estimates that a shift to net zero could see the number of “green collar jobs” grow to two million. At the time of announcing the net zero legislation, the low carbon sector already supported almost 400,000 jobs nationwide - and the value of exports from the low carbon economy grow to £170 billion a year by 2030.

Net zero means that the overall balance of emissions is zero. That isn’t the same thing as having no emissions at all. For example, a country with 10,000 annual immigrants and a 10,000 annual emigrants obviously has migration activity, but it would be described as having “zero net migration” because numbers in are equal to numbers out.

It’s the same principle with emissions. It’s almost impossible to emit absolutely nothing, but we can achieve net zero if the emissions we produce are balanced by the emissions we absorb. The Committee on Climate Change suggests the best ways to increase the UK’s carbon absorption would be to turn some of our farmland over to tree planting and restoring peatlands.

Limiting climate change requires a coordinated global effort on a scale that has never been seen until COVID-19, so it is discouraging when some countries seem to be undermining the efforts of others. But global action is happening, and it’s gathering pace.

• Every country in the world has signed up to the United Nations Framework Convention on Climate Change (UNFCC).
• The Paris Agreement in 2015 saw 160 countries voluntarily pledge to reduce their carbon emissions by 2030. Signatories included China, the USA and every country in the EU.

You don’t have to look far to see impressive examples of carbon reduction innovation from countries of all sizes. Morocco has created the world’s biggest solar farm, India is on track to hit its renewable energy target ten years early and the Gambia is restoring forests and mangroves to act as carbon sinks. The USA may currently be breaking its promises under the Paris Agreement, but countries that refuse to act on climate change are in the minority. As the world’s fifth largest economy, the UK has an opportunity to show global leadership on this issue.

If you travel by air, flying is very likely to be the biggest contributor to your personal carbon footprint, and it’s almost impossible to offset this with other lifestyle changes. Going vegetarian for a year might save half a tonne of carbon, while driving 2000 miles less per year would save about 0.8 tonnes. The carbon savings you make in a year with either of those big changes would be wiped out in a day by one flight from London to New York (nearly a whole tonne).

To put it in a global perspective, the average person living in Bolivia will only emit 0.47 tonnes in a whole year. There are many other countries where the average person’s annual emissions are below the level of a single long-haul flight.

Unfortunately, there is currently no way to make your flying greener. Although the world’s first fully electric commercial aircraft took off last year, this technology probably won’t become widely available for years yet. There have been advances in making planes more fuel-efficient, but mile for mile, flying is still the most emissions-intensive form of transport.

Individuals can easily offset their personal carbon emissions once they have reduced them as much as possible. This site allows you to calculate your emissions and purchase offsets.

Yes. Although the energy powering your business or home is almost certainly coming from the grid, choosing a “100% renewable” tariff still makes a difference. Suppliers have to match the renewable energy bought by their customers with the amount they buy from generators, so when you choose renewables you are helping to make the UK’s energy mix greener.

More and more businesses are also choosing to buy their electricity directly from renewable energy generators such as a solar and wind farms, under corporate power purchase agreements (CPPAs).

A warmer earth might mean that cooler countries get milder winters. This might mean fewer winter deaths and less fuel poverty. In a warmer world, colder countries might also be able to grow a bigger range of food crops than before. However, these possible future benefits are drastically outweighed by the harm already being caused right now, let alone by the greater harm that we risk in future decades.

The World Health Organisation estimates that climate change is already causing 150,000 deaths every single year. If we take no action on climate change, far more people will die from climate-related causes such as extreme weather events, drought and malnutrition caused by failing food crops. We have lost 60% of all wildlife in the last 50 years, while the number of new infectious diseases has quadrupled in the last 60 years. Given recent events, the evidence that climate change increases disease transmission is particularly alarming. As the climate continues to change this rate could exacerbate further.

There isn’t a straightforward answer to this, as it depends on the type of heating system (gas boilers, heat pumps, electric panel heaters) in use as well as the type of heat emitters (underfloor heating, radiators, convectors etc.).

Probably the most important comparison to make is between an electric air source heat pump or a gas boiler; boilers only deliver about 0.9 units of heat for one unit of energy used, whereas heat pumps deliver about 3 units of heat for one unit of electricity used. Taking into account the associated carbon emissions factors, provided that the heat pump has a Seasonal Performance Factor of more than ~1.7 then it is likely to have a lower carbon emissions impact then the boiler.