Environmentalists have urged the government to avoid ‘fiddling’ its carbon emission reduction figures following its landmark announcement to legislate for net-zero emissions.

The legislation, tabled today (Wednesday), will increase the UK’s existing target that emissions should be 80% of 1990 levels by 2050.

Responding to Theresa May’s announcement, Friends of the Earth chief executive Craig Bennett said it sent “a powerful message to industry and investors that the age of fossil fuels is over”.

But, he expressed disappointment that the government has announced a review of the target in five years’ time to assess whether the UK’s efforts are being matched by competitor nations as well as its decision to retain the ability to use international carbon credits to meet emissions cut targets.

“Fiddling the figures would put a huge dent in our ability to avoid catastrophic climate change – and the government’s credibility for taking this issue seriously. Having declared a climate emergency, Parliament must act to close these loopholes.”

The legislation should also accelerate progress on decarbonisation, he insisted: “2050 is still too slow to address catastrophic climate change, the UK can and must go faster. The next prime minister must legislate to end our contribution to climate breakdown earlier, put carbon-cutting at the centre of policy-making and pull the plug on plans for more roads, runways and fracking.”

However the announcement has received a warm welcome from the industry.

Keith Anderson, chief executive of Scottish Power, said: “To deliver this race to zero we will double the amount of electricity we use, therefore we need to quadruple the amount of renewable energy we make. That’s going to require bold innovation alongside market and regulatory frameworks that encourage significant and sustained investment.”

John Pettigrew, chief executive of National Grid, said: “Government has shown today the right leadership in legislating for a 2050 net-zero target. Britain has an opportunity to cement its global leadership in reducing emissions, and to create new economic opportunities as a result. Industry and government must now work together to make the huge progress needed in the decarbonisation of heat and transport, building on the good work which has begun.

“As the first major economy to legislate for net-zero, we should all now get behind the UK’s bid to host the UN Framework Conference on Climate Change (UNFCC) COP26 conference next year.”

Richard Black, director of the Energy and Climate Intelligence Unit (ECIU), agreed: “It’s going to act as a massive spur to the UK’s bid to host the UN climate summit in 2020, because the UK can now legitimately say that it has done what all governments will have to soon, committing to ending its contribution to climate change.”

He also said the announcement provided businesses with the clarity they need to invest in the transition to a clean energy economy.

“This is probably the most important UK move on climate change since Parliament brought in the Climate Change Act more than a decade ago.

“By becoming the first major nation to set a net zero target in national legislation, ahead of the likes of France and Germany, it restores the UK to a position of international leadership with a target that’s fully in line with science and will deliver the UK’s fair share of keeping global warming below the ‘safe’ level of 1.5 Celsius.”

Lawrence Slade, chief executive of Energy UK, urged the government to get on with developing the detailed policies required to implement the net-zero target.

He said: “Net-zero can be achieved but only if the ambition is supported by the right policies. As our recent Future of Energy report highlighted, we need to go further and faster in areas like decarbonising transport and heating and improving the energy efficiency of our homes and businesses. This can only happen with consistent and bold policy-making from across all government departments to support the target and we look forward to working with the government to achieve our shared ambition.”

He was backed up by Rachel Reeves, chair of the BEIS (Business, Energy and Industrial Strategy) committee, who tabled legislation yesterday to implement the net-zero target ahead of the government’s move.

She said: “This commitment can only be the first step. The government will now need to come forward with the co-ordinated policies, actions, and regulations needed to achieve net zero emissions by 2050.”

Simon Virley, UK head of energy & natural resources at KPMG, said that while there had been substantial progress on decarbonising the power, heating will require the deployment of a range of new technologies.

“We need a proper debate with the public on how best to do this and how to minimise the costs involved. The government should now take a lead in forming the policy frameworks that will support technological innovation and protect our environment for future generations.”

Sir John Armitt, chair of the National Infrastructure Commission, said the government’s National Infrastructure Strategy, which is due to be published during the autumn, must be “unambiguously bold” in setting a “clear and achievable path to ensure the UK becomes a low-carbon nation”.

David Smith, chief executive of Energy Networks Association, stressed the importance of the government acting in conjunction with the regulator immediately to get the policies in place to the 2050 target into a reality, adding: “The time for waiting is over”.

“We need to invest to innovate and to deliver the right infrastructure at the lowest possible cost to the public. That will mean more renewable energy projects, more electric vehicle charging points and a decarbonised gas grid, for which hydrogen is an absolute necessity. Public support for net zero is key, and so we must have the tools to deliver for them.”

Chief executive of the Energy and Utilities Alliance (EUA), Mike Foster, echoed the call, saying: “Now it’s the turn of the policy makers to create the environment in which industry can achieve net zero. For policy-makers grappling with how to decarbonise heat, they need to keep focussed on peak heat demand.

“Green gases such as Hydrogen, Biomethane and bio SNG are being increasingly recognised as the preferred solution to meet UK heat demand, which is seasonal and demands a flexible supply. Our members are poised to deliver and ready to work collaboratively with Government to introduce it into people’s homes, businesses and into the UK transport network. EUA believes that green gas addresses the energy trilemma by providing a secure, affordable and flexible source of energy.”

At the Solar Trade Association, chief executive Chris Hewitt, also took the view that “long-term targets are meaningless without action”.

He said: “In the case of solar and energy storage the government must move quickly to remove barriers that have needlessly slowed progress. In contrast to the view of the Treasury the whole country will benefit from the energy transition if government creates a level playing field for all clean energy generation technologies to compete on. Solar and wind are now the lowest cost forms of power generation in the UK, yet there is no route to market and government is continuing to subsidise the fossil fuels it is aiming to phase out.

“A 100% renewable energy system, including powering heat and transport, is entirely possible but only with the integration of energy storage which represents a notable industrial opportunity for the UK. The sector is yet another example of the tremendous potential economic opportunities in clean energy if the government gets pathways to commercialisation and mass market deployment right.”

Dr Tim Rotheray, Director of the Association for Decentralised Energy insisted that what was needed now was “a revolution in the way in which we generate and use our energy, putting businesses and household energy customers at the centre of energy decision making”.

He called for a new energy policy to be developed that would reward users for cutting carbon in heat, power and transport, alongside large scale investment.