This week, more than 400 climate scientists from UK research institutes published an open letterAhead of the general election on 4 July, he called on UK political parties to commit to stronger climate action in the next Parliament.

Their demands included a “credible” carbon reduction strategy for the country, during an election campaign where there has been little in-depth discussion about the UK's transition to net zero.

Why are scientists worried? After all, the UK has one of the most ambitious climate targets in the world – a legally binding target to reach net-zero emissions by 2050 – and has halved its greenhouse gas emissions since 1990.

But the truth is that the UK's race to net zero has slowed in recent years, with annual emissions Half the rate needed to achieve the intermediate goal.

While great progress has been made in decarbonizing the electricity supply, with around half of all electricity now generated from zero-carbon sources, other sectors are lagging behind. The Committee on Climate Change, the UK government's climate advisers, say that outside the electricity sector, the rate of emissions reductions needs to quadruple over the next seven years for the UK to meet its commitment to cut emissions by 68% by 2030. I said in OctoberHe warned it was “unlikely” the UK would get there under current plans.

“There's a real sense of frustration in the climate science community,” he said. Emily Schuckberg “We are yet to see the level of response that is required,” said a Cambridge University researcher who co-authored the scientists' letter.

The slow progress means problems are piling up, waiting for the next administration to tackle them.

Transportation and Buildings

By the end of the decade, emissions from surface transport – roads, rail and ships – need to fall by around 4 million tonnes of carbon dioxide equivalent, four times the rate of reduction over the past decade. Electric car sales may be growing strongly, but sales of electric vans and trucks are sluggish, and the number of public charging points is not growing fast enough to keep up with the volume of electric vehicles travelling. Meanwhile, public transport use has fallen sharply during the COVID-19 pandemic, It's not back to the previous level.

Getting the transport sector to net zero will require more than just convincing everyone to buy electric cars, Michael Pollitt The Cambridge researchers say that reducing the number and size of cars is a key part of the puzzle. “We need more radical thinking about intercity transport, including prioritising lanes for small vehicles and dramatically reducing the size and weight of vehicles,” they say. “If people can travel in significantly smaller cars and public transport, that's the route to net-zero transport.”

When it comes to buildings, home heating is the biggest pain point. Around 23 million homes in the UK are heated by gas boilers. By the middle of the century, all of these homes will need to be heated with zero-carbon energy sources, and it is expected that most will switch to heat pumps.

But the pace of the transition is too slow: just 69,000 heat pumps will be installed in UK homes in 2022, far short of the target of 600,000 per year by 2028. Part of the problem is finances: heat pumps are much more expensive to install than gas boilers, and they are often more expensive to run as well, due to an additional levy on grid costs. “We absolutely have to get the price of heat pumps down,” Porritt says. “Unless the price of heat pumps comes down significantly, they will be a major obstacle to decarbonising heating.”

It is urgent to solve these problems. Nick Air One Oxford professor who signed the open letter said that a gas boiler installed in 2035 would still be heating homes in 2050. “For heat pumps and cars, we need to be pretty much sorted by the early 2040s, which means we need to get very serious about it in the 2030s,” he said.

That's why the UK government's inaction over the last decade, when it should have been focusing on preparing industry for mass adoption, is so worrying. “We know what needs to be done,” Eyre says, “but the last two years in particular have been a period of no real action being taken.”

Agriculture and Aviation

Beyond heat, power and transport, tougher choices lie ahead. For example, emissions from agriculture and land use have remained almost unchanged for a decade, but need to be reduced by 29% by 2035. Achieving these reductions will likely require actions to change the way people eat. Similarly, reducing aviation emissions will require actions to curb demand, such as taxes on frequent flyers.

“The biggest challenge is starting to implement policies and regulations that will affect people's daily lives.” Leo Mercer “If policies are not communicated well, people will react quite strongly,” said the professor at the London School of Economics.

Alongside its domestic challenges, the UK needs to rebuild its reputation on the international stage: under former Prime Minister Boris Johnson, the UK hosted the COP26 climate summit and led international coalitions on deforestation, methane and electric vehicles.

However, progress on climate change measures in the UK has slowed, cuts in international aid and climate diplomacy; Britain's international reputation has suffered, and the government's decisions to approve new fossil fuel projects in the UK while urging lower-income countries to “move away” from fossil fuels have also antagonized the British public.

Unless a country like the UK can demonstrate that net zero is achievable and desirable as a national strategy, it will face an uphill battle to persuade lower-income countries to cut emissions, which is why it is crucial the UK restores its reputation as a climate leader in the next parliament, he says. Katerina Brandmeyer At Imperial College London.

Next year, countries are due to submit new commitments under the Paris Agreement to reduce greenhouse gas emissions by 2035. “So this is a pivotal moment for the international community,” she said. “This parliament will be crucial not only to ensuring delivery in the UK, but also to raising ambition globally.”

What each party is proposing

So which party can take action on the scale needed to get the UK back on track? All the major parties agree on the need to reach net zero by mid-century, and Labour and the Conservatives are remarkably in agreement on the need for renewable energy, particularly offshore wind.

But Labour has made an eye-catching promise to deliver a fully decarbonised electricity grid by 2030. Adam Bell A former senior UK government official at Stonehaven, a British consultancy, said the target was “highly ambitious” and would push government agencies to the limits of their capabilities. [Labour] It could be even more ambitious.”

But for Eyre, a credible climate manifesto should also include ambitious targets in the areas where the UK is seriously off track: home energy efficiency, heat pump adoption, industrial emissions, land use, solar power and electric vehicles. “It's not a matter of doing one or two of them,” Eyre says. “We need to do them all.”

Many experts privately doubt that the major parties have policy programmes with the pace and scale needed to get to net zero by 2050. Absent that, looking for enthusiasm for the challenges ahead may be the next best way to gauge a party's credibility. In Eyre's eyes, the next UK government is embarking on a “10-year plan on the scale of the introduction of the steam engine.” “If you don't have a positive vision yourself, you're not going to sell it to the public,” he says.