May’s plan to reduce emissions to net zero slammed after it emerged the target will be reviewed

– Why do we need to aim for zero emissions?

As more greenhouse gases lead to more warming, stabilising the planet’s temperature at any level will require global emissions to fall to zero overall.

A key UN report last year said that to keep temperatures from rising to more than 1.5C in the long-term, countries need to cut carbon emissions to net zero by 2050, with steep cuts in other greenhouse gases such as methane.

– What does net zero mean?

It means cutting emissions to as close to zero as possible and using methods to take greenhouse gases out of the atmosphere to “offset” the remaining pollution – for example by planting trees which absorb carbon dioxide.

Prime Minister Theresa May and Chancellor Philip Hammond in the Commons earlier this year – Hammond raised concerns the plan would cost £1 trillion

– What happens if we do not do it?

We have already experienced 1C of warming, and commitments by countries to cut their emissions leave the world on track for rises of 3C by 2100.

Temperature rises of more than 1.5C are set to increase extreme weather events such as heatwaves and flooding, cause greater losses in crop yields and wildlife and raise the risk of large-scale irreversible impacts such as melting ice sheets which will push up sea levels.

– We are just one country. How much of a role can the UK play?

While the UK’s current emissions make up only a small percentage of the overall global output, the country led the industrial revolution and has made a major contribution to greenhouse gas pollution over time.

Cutting all greenhouse gas emissions to net zero by 2050 will meet the UK’s commitments under the Paris Agreement to limit global warming and provide leadership for other countries to follow suit.

– Can we do it?

The Government’s advisory Committee on Climate Change recommended last month that ministers should set the target as soon as possible.

In its recommendations, it concluded that it can be done with known technologies and within the expected economic cost that Parliament accepted when it set the current 2050 target for an 80% cut on 1990 levels.

But it will require “clear, stable and well-designed policies” to reduce emissions further across the economy without delay, the experts say.

And moving to a zero emissions economy must be fair on workers and consumers.

– What will it involve?

Phasing out greenhouse gases over the next three decades will require changes in all areas of the economy including more low-carbon power, electric vehicles, tackling emissions from aviation and industry and changes to how land is used and buildings are heated.

The Government has said it will retain its ability to use international carbon credits to meet the goal, which pay to offset emissions with reductions elsewhere in the world – a loophole campaigners want to see closed.

A free recharging station - as part of the plan low-carbon vehicles would have to see an increase

A free recharging station – as part of the plan low-carbon vehicles would have to see an increase

– What can people do in their own lives to reduce emissions?

Active engagement from households to reduce their carbon footprint will be vital to achieve net zero, the Committee on Climate Change has said.

People can choose to walk, cycle or take public transport or make their next car an electric one, and minimise flying.

They can improve the energy efficiency of their homes, as well as setting thermostats no higher than 19C, and consider installing low-carbon heating systems.

Eating a healthy diet – such as cutting down on beef, lamb and dairy can also help tackle emissions, as can reducing food waste, buying peat-free compost and sharing or buying items like power tools that are not often used.