By Roger Harrabin
Environment analyst, BBC News
The Copenhagen conference could be "make or break time for the climate".
The prime minister is to pledge UK leadership in the international battle against climate change.
He is due to launch a document showing what the UK will offer to the Copenhagen conference tasked with forging a new global climate agreement.
Climate Secretary Ed Miliband described the conference as "make or break time for the climate".
The Road to Copenhagen document will outline plans for ongoing emissions cuts in the UK.
It will also contain practical advice to people on how they can cut emissions and often save money too.
The document will focus on UK ambitions for the Copenhagen conference and also for the G8 meeting, soon to take place in Italy.
At that summit, leaders of the world's top polluting nations - including emerging economies - will attempt to clear a path for a global deal.
The UK plays a leading role in international negotiations and is on track to exceed the targets for emissions cuts agreed under the current Kyoto Protocol.
But new figures from the Stockholm Institute - a respected research body - throw a different light on the UK's performance.
The climate department DECC says, for instance, that although China's total emissions are immense, the average European is responsible for emitting twice as much greenhouse gases as the average person in China.
But the official tally of emissions does not include aviation and shipping, and it takes no account of emissions embedded in imported goods.
When these are taken into account, the institute calculates that the average UK resident pollutes 15 tonnes a year - almost five times more than the average Chinese person at 3.1 tonnes a year.
This implies that the UK should be making much deeper cuts in emissions than are already planned.
The Scottish Parliament voted this week to cut Scottish emissions by 42% by 2020, compared with a UK target of 34%.
The Scottish cuts will include aviation and shipping, but not embedded emissions.
The failure to calculate embedded emissions has damaged the reputation of countries such as China that are making goods for export to the West but are then blamed for the pollution that results.