The UK government has won a legal fight over a planned £27 billion ($37bn) expansion of the country's road network despite concerns the programme is at odds with its commitment to tackle climate change. A High Court judge said on Monday that environmentalists had failed to show that the government had acted irrationally when agreeing 50 new building projects to add to 7,250 kilometres of motorways and major roads. Campaigners had called for the projects to be declared illegal on the grounds that they are at odds with the UK’s pledges to tackle carbon emissions agreed under an international climate deal. But the judge ruled that Grant Shapps, Britain's transport secretary, had received a briefing, “albeit laconic”, from officials when he was assured that the programme for new building from 2020-2025 was in line with the country’s commitments to tackle climate change. “The government is taking a range of steps to tackle the need for urgency in addressing carbon production in the transport sector. Whether they are enough is not a matter for the court”, Mr Justice Holgate said. The defeat is the second major defeat for campaigners after the UK’s highest court in December ruled against them over a planned third runway at Heathrow, the UK’s largest airport. Environmentalists had also claimed in that case that the decision was not in line with the UK's international commitments. Under the 2015 Paris Agreement, the UK and most other countries have agreed to try to limit global warming to 1.5<b>°</b>C above pre-industrial levels. Current global policies put the planet on track for a 2.9<b>°</b>C rise, according to research organisation The Climate Change Tracker. Prime Minister Boris Johnson's government is aiming for net zero carbon travel on the roads within 30 years. The group that brought the roads action, the Transport Action Network, said it would appeal the judgment. Major UK roads that make up the “strategic network” account for just 2 per cent of all highways but are responsible for nearly two-fifths of all greenhouse gas emissions. Campaigner Rebecca Lush said the emergence of a new generation of environmentally-friendly cars would come too late to reverse the most devastating effects of climate change. “This road building programme belongs in the last century,” she said. “The critical time is now.”