Boris Johnson has urged other world leaders to follow with ambitious targets at the virtual climate summit he is hosting on 12 December.
The announcement has been broadly welcomed, although scientists say it does not guarantee dangerous climate change will be avoided.
They urged Mr Johnson to impose policies to back up his ambitions currently the UK is slipping behind its existing targets.
The National Audit Office, the government spending watchdog has revealed the challenge will be colossal and affect the way we work, travel, heat our homes and even how much meat we eat.
The Committee on Climate Change has recommended the UK should commit to cutting emissions by at least 68% on 1990 levels by 2030, under its Paris plans, known as nationally determined contributions or NDCs.
The 68% cut would be a “clear progression” from existing commitments under domestic law, which require a 61% reduction by 2030, the committee said.
In a letter to Business Secretary Alok Sharma, the advisory committee said cuts of that level would be in line with the UK’s international commitments and would place the UK “among the leading countries in climate ambition”.
Prime Minister Boris Johnson said:
“We have proven we can reduce our emissions and create hundreds of thousands of jobs in the process – uniting businesses, academics, NGOs and local communities in a common goal to go further and faster to tackle climate change.
Today, we are taking the lead with an ambitious new target to reduce our emissions by 2030, faster than any major economy, with our Ten Point Plan helping us on our path to reach it.
But this is a global effort, which is why the UK is urging world leaders as part of next week’s Climate Ambition Summit to bring forward their own ambitious plans to cut emissions and set net zero targets.”
Business and Energy Secretary and COP26 President Alok Sharma said:
“Tackling climate change is the one of the most urgent shared endeavours of our lifetimes, demanding bold action from every nation to prevent catastrophic global warming.
As a country, we have demonstrated we can both rapidly cut carbon emissions, while creating new jobs, new technologies and future-proof industries that will generate economic growth for decades to come.
The UK’s new emissions target is among the highest in the world and reflects the urgency and scale of the challenge our planet faces. I hope other countries join us and raise the bar at next week’s UN Climate Ambition Summit, and ahead of the COP26 climate conference in Glasgow”
Ed Miliband, the shadow business secretary, said: “We welcome the important strengthening of the 2030 UK target. But this is the minimum we should aim for.”