Prime Minister Boris Johnson says the UK is "taking the lead with an ambitious new target to reduce our emissions".
The government has promised to cut greenhouse gas emissions by more than two thirds (68 percent) of what they were in 1990 by 2030. The announcement is known as an NDC - or nationally determined contribution - and is a key factor in efforts to tackle climate change.
Under the Paris climate change agreement of 2015, all countries are obliged to update their commitments to cut emissions and deliver NDCs by the end of 2020.
The UK is the first major economy to announce its NDC and is hoping its promise to effectively increase the emissions reduction from 53 percent to 68 percent will encourage other countries to follow suit. The emissions are measured against the level they were in 1990.
Boris Johnson said: "We are taking the lead with an ambitious new target to reduce our emissions by 2030 faster than any major economy. But this is a global effort."
The government is making the pledge a week before hosting a virtual climate ambition event marking a year to the landmark COP26 climate conference, which has been delayed until November 2021 because of the COVID-19 pandemic.
The UK's emissions promise is in line with what the Committee on Climate Change, which independently advises the government, says is necessary to meet the legally binding target of the UK reaching net zero by 2050.
Johnson's pledge is ambitious, given current figures show the UK has only reduced its emissions by 45 percent since 1990. However, Richard Black, director of the Energy and Climate Intelligence Unit, said: "Britain is out ahead of most of the other big nations, it's committed more than the EU is likely to do, and it's more than the US is likely to be able to do, and certainly more than the likes of Australia have done."
"It's roughly on track for getting to the legally binding net zero target and the hope clearly is that it will encourage other countries to come forward."