Net zero: What is it and why does it matter?

A new plan to cut greenhouse gases and lower energy costs by investing in renewable energy and nuclear is being unveiled by the Government on Thursday.

The Net Zero plan has numerous measures to cut emissions including announcing the first carbon capture sites. Carbon capture is the process of trapping carbon dioxide produced by burning fossil fuels or other chemical or biological processes and storing it in such a way that it is unable to affect the atmosphere. This is with the aim of mitigating the effects of global warming.

Ministers say they want the UK to have the cheapest electricity in Europe by 2035, but admit the strategy is unlikely to bring down bills next year.

The 30-page Powering Up Britain document contains many measures covering offshore wind, nuclear and green hydrogen, though many had already been announced previously.

But Labour said the plans were a “rehash” with no new investment.

The plans contain no new Government spending. Some campaigners have said they have missed out key elements, such as a comprehensive programme of home insulation and a full lifting of the ban on new onshore wind turbines in England.

Environmental group Friends of the Earth is looking over the new revised net-zero strategy to see if it still fails to meet legal obligations to cut carbon emissions.

So what is “net zero” and why does it matter?

What does net zero mean?

Net zero means not adding to the amount of greenhouse gases in the atmosphere.

Greenhouse gases, such as carbon dioxide, trap heat and keep the planet warm.

But the more of these gases we have put into the atmosphere through activities such as burning fossil fuels to heat homes, driving cars and providing electricity for our lives, the more the planet warms.

These rising temperatures drive climate change, the extreme weather, rising sea levels, heatwaves, and floods that we are already seeing increase around us.

So, just as you need to turn off a tap completely to stop the level of water in a bath from continuing to rise, we need to cut emissions to zero to reduce greenhouse gas levels, and therefore temperatures, to prevent more dangerous climate change.

Under the 2015 Paris Agreement, 197 countries agreed to try to keep future global temperature rises “well below” 1.5C to avoid the worst impacts of climate change.

How can we achieve net zero?

Completely stopping emissions is extremely difficult. However, there are some measures, such as planting trees, which can absorb greenhouse gases from the atmosphere. This is the equivalent of bailing some water out of the bath to keep the water level steady even if the tap is still running slightly.

Not all emissions can be reduced to zero, so those that remain have to be compensated by removing greenhouse gases from the atmosphere. This is known as “offsetting”.

To stabilise global temperature at any level, emissions must reach this “net-zero” point eventually.

Scientists say that to limit temperature rises to 1.5C above pre-industrial levels — beyond which increasingly dangerous climate impacts will be felt — global carbon emissions must be brought down to net zero by around 2050. They say deep cuts to other greenhouse gases are also essential to achieve this.

The UN’s Intergovernmental Panel on Climate Change(IPCC) has said that significant amounts of carbon dioxide removal will not only be needed for mopping up residual emissions, but also for creating negative levels of emissions to reduce temperatures after overshooting the 1.5C level.

In the UK, the Government legislated in June 2019 that the country must reach net-zero greenhouse gas emissions by 2050, by mandating a 100 per cent cut in emissions by that date.

That requires deep cuts in emissions and therefore changes in all sectors. These include how we heat our homes, travel, our power sector, how industry uses energy, our diets, and efforts to capture some emissions.

The statutory advisory Climate Change Committee (CCC) has said it expects more than 100 million tonnes of emissions will be captured in 2050 to offset the pollution the UK is still putting out then.

Ways to do that include burning plant matter for energy; capturing and burying the carbon emissions, known as bioenergy with carbon capture and storage (BECCS); technology that captures carbon dioxide directly from the air; expanding woodlands; and restoring peatlands.

What are the challenges in achieving net zero?

Delivering net zero is not without controversy, with concerns raised about the cost.

But the CCC has concluded it would cost less than 1 per cent of gross domestic product (GDP) through the next 30 years to deliver. It would also bring benefits such as cleaner air, better health and provide a jobs boost, though there is a need to ensure the costs are spread fairly.

It is also contentious because some environmentalists are concerned some companies and governments think they can continue to pollute while “offsetting” themselves out of the crisis, instead of tackling the emissions at source.

However, the CCC’s chief executive Chris Stark has said setting a net-zero target is the right approach, and the goal has galvanised action.

He said it was different from the UK’s old target of 80 per cent emissions cut by 2050. Mr Stark said this was because there was no longer a 20 per cent of residual pollution that organisations or sectors thought they could emit.

“I see real progress having set net zero as a goal, not just in government circles and in policy, but crucially in the commercial sector,” he said.