Climate campaigners have launched two separate legal challenges to government plans to open a massive new oilfield in the North Sea. Greenpeace and the campaign group Uplift argue that the decision to press ahead with the Rosebank development – the UK’s biggest untapped oilfield – is incompatible with the UK’s legally binding climate commitments, and say ministers’ original analysis ignored the devastating impact of burning oil from the site. Tessa Khan, executive director of Uplift, said: “If Rosebank goes ahead, the UK will blow its own plans to stay within safe climate limits. It’s that simple. If the government disagrees, it needs to provide evidence and prove it in court.” The field was given the green light in September and has the potential to produce 500m barrels of oil in its lifetime, which when burned would emit as much carbon dioxide as running 56 coal-fired power stations for a year. The project has faced stiff resistance, with hundreds of climate scientists and academics and more than 200 organisations, from the Women’s Institute to Oxfam, joining tens of thousands of people across the UK in opposing it. It also flies in the face of warnings from scientists about the impact of the development on the climate, and repeated statements from the International Energy Agency that no new oil and gas exploration should take place if the world is to limit global heating to 1.5C above pre-industrial temperatures. Greenpeace UK’s co-executive director, Areeba Hamid, said: “Rosebank’s development was approved under the false claim that it is entirely compatible with the UK’s legally binding climate commitments. This is a lie. “The government used a rigged climate assessment to approve its development, deliberately ignoring all the emissions that will come from burning the 500m barrels of oil it contains. It’s like building a bomb and claiming it’s completely harmless so long as no one detonates it.” Campaigners say the UK public will carry almost all the cost of developing the field, while Rosebank’s owners are set to receive around £3bn in tax breaks. And they claim the project will not cut household energy bills, as the oil sold on the world market would make no material difference to the price UK consumers pay. A spokesperson for the government rejected the claims and said it would “robustly defend” the legal challenges. “The UK is a world leader in reaching net zero – cutting emissions faster than any other major economy – and, as the independent Climate Change Committee recognises, we will still need oil and gas as part of our energy mix. “We will continue to back the UK’s oil and gas industry, which underpins our energy security, supports up to 200,000 jobs, and will provide around £50bn in tax revenue over the next five years – helping fund our transition to net zero.” In a report in June, the Climate Change Committee said: “The UK will continue to need some oil and gas until it reaches net zero, but this does not in itself justify the development of new North Sea fields.” Greenpeace and Uplift have both applied to the court of session in Edinburgh for a judicial review of the decision by the energy secretary, currently Claire Coutinho, and the North Sea Transition Authority. The court is expected to rule on whether or not to grant permission for a full hearing of the case early next year.