New oil and gas licences for the North Sea that the UK government has approved in the past two years will produce as much carbon dioxide as the annual emissions of nearly 14m cars, or the entire yearly emissions of Denmark, analysis has shown. This amount – about 28m tonnes of carbon dioxide over the lifetimes of the fields – will be increased more than eightfold, if potential licences under consideration are also granted, according to data from public sources analysed by Greenpeace. Three large oil and gasfields have been approved since the International Energy Agency warned in May 2021 that no new developments of fossil fuels could be constructed if the world was to limit global temperature increases to 1.5C above pre-industrial levels. The IEA report was conducted at the behest of the UK government, which was preparing to host the Cop26 climate summit. Since then, the government has put in place a “climate checkpoint”, assessing potential new licences before drilling can take place. But the checks focus on the greenhouse gas emissions associated with exploring and operating new fields, rather than taking into account the emissions – known in climate jargon as “scope 3” emissions – that are generated from burning the fossil fuels produced from the fields. Greenpeace argues that failing to take these emissions into account in official impact assessments makes a mockery of the UK’s climate goals. In a court case expected to be heard on Tuesday, the group will seek to establish that the government’s actions are unlawful. Philip Evans, a campaigner at Greenpeace, said: “As large parts of Europe, North America and Asia are gripped by a hellish heatwave, we can see that the climate crisis is spiralling out of control, yet the government is insisting on massively expanding oil and gas drilling that will only make it worse. “As if that wasn’t scandalous enough, when making these decisions ministers deliberately ignore the emissions from burning all these new fossil fuels. That’s grossly irresponsible.” Government ministers face a fresh assault on green issues. The byelection held in Boris Johnson’s former seat, Uxbridge and South Ruislip, was judged to have been lost by Labour, which keenly targeted the seat but was defeated by a margin of 495 votes, because of voter concern over the expansion of London’s ultra-low emissions zone (Ulez). Ulez, which was originated by Johnson and stipulated by the Conservative energy secretary, Grant Shapps, in an agreement with the London mayor, Sadiq Khan, will affect only one in 10 motorists. However, many people in the highly car-dependent constituency raised concerns before its rollout, scheduled for the end of August. The byelection result has revived a culture war in the media in which rightwing Conservatives and elements within the Labour party have pushed for rolling back green measures. Keir Starmer, the Labour leader, stoked fears for the party’s green commitments at the weekend, saying the party was “doing something very wrong”. A Tory party source told the Guardian there would “definitely” be more to come from Shapps, who has repeatedly called Labour “the political wing of Just Stop Oil”. Before the byelection result, the climate minister Graham Stuart said there was cross-party agreement on the need to achieve net zero but told the Guardian the Labour party was “the lunatic fringe”. Khan is understood to want to push ahead with Ulez, with local campaigners arguing that the Uxbridge campaign was characterised by “dirty tricks” that misrepresented the scheme, and the mayor believes the reality would reassure voters. Sources within the Labour party told the Guardian Starmer was not feeling pressure to change his stance on green issues. Greenpeace will argue in the judicial review hearing that the government is reneging on its climate commitments by giving the green light to new oil and gasfields in the North Sea. The three largest approved since the IEA report are Jackdaw, Abigail and Talbot, the emissions from which are the equivalent of seven coal-fired power stations, according to Greenpeace. If Rosebank and Cambo, two other large fields under review, are approved the total will rise to about 240m tonnes of CO2, equivalent to running 64 coal-fired power plants for a year, or the annual emissions of Spain. Evans said: “Rishi Sunak’s government seems to have stopped listening to the experts on climate. Instead, they are bending over backwards to promote the interests of the fossil fuel industry, at the expense of bill-payers and the climate.” A spokesperson for the Department for Energy Security and Net Zero said: “Development proposals for oilfields under existing licences are a matter for the regulators, with the environmental impact of proposed developments subject to rigorous regulatory assessment, including a full environmental impact assessment and public consultation. “The transition to non-fossil forms of energy cannot happen overnight and even when we’re net zero, we will still need some oil and gas, as recognised by the independent Climate Change Committee. Sourcing gas domestically is also better for the environment as it has a lower carbon footprint than importing from abroad.”