Meanwhile, a global group of experts, with headquarters at the CSIRO in Canberra, is preparing to release its annual carbon budget on Tuesday - a report card for the world on the greenhouse gases.

The Global Carbon Project, which began in 2001, involves scientists and institutions from around the world. Unlike the Intergovernmental Panel on Climate Change - which looks at the existing scientific literature, reviews it and writes a report - the project facilitates collaboration between scientists, identifies areas that need further investigation and drives the research agenda.

Dr Josep Canadell is a scientist in CSIRO's Marine and Atmospheric Research in Canberra, and executive director of the Global Carbon Project. He says the project is the only international collaboration addressing the underlying cause of climate change, the human contribution to the carbon cycle, in a holistic way.

Preparing a carbon budget for the whole world is an enormous task. Dozens of big international stations measure greenhouse gasses in the atmosphere with great precision.

''That's why when we say carbon dioxide and other greenhouse gases are accumulating and its concentrations are going up and up, we know this very well,'' Dr Canadell said.

But the scientists also need to consider land use and deforestation, worldwide energy consumption and the resulting carbon emissions, how much carbon gets taken up by vegetation and how much ends up in the oceans.

They use many different models, developed over decades by large research institutions.

''Emissions need to equal what accumulates in the atmosphere, what goes into the ocean and what goes onto land, and if things don't quite match and come together, we need to go back to the drawing board, rerun things, understand what was the problem until things start making sense,'' Dr Canadell said.

Emissions have been growing at a rate of 3 per cent since 2000, he said, three times the rate of the 1990s, but deforestation has decreased, which is ''great news''.

The budget provides up-to-date information to policy-makers on how the world is doing on carbon abatement. ''It gives almost constant feedback to these negotiations, which, of course, have their own issues, which are largely political issues, and we're trying to go there and say, 'These are the facts, this is the data'.''

The politicisation of their science is frustrating, both Dr Canadell and colleague Dr Michael Raupach agree.

Dr Raupach was one of the project's original co-chairs. He said carbon science often gets distorted, in part by accident, because it is complex, but also in part deliberately.

He said inaccurate information is written in sceptic blogs and websites all the time, spreading the idea that CO2 only represents only a minuscule portion of the atmosphere, and therefore does not matter. ''That argument is invalid on half a dozen grounds.''

Or the notion that global warming has stopped over the past 15 years, which is sometimes repeated by commentators in the mainstream media.

It is statistically wrong, Dr Raupach said, and does not take into account the amount of heat that is going into the ocean, which changes from year to year.

''The arguments on those sites have been refuted a million times.''

Dr Raupach will not comment on the new Coalition government's direct action plan for reducing carbon emissions, which involves scrapping the carbon tax and instead spending $2.88 billion over four years to pay for emission cuts by businesses and farmers.

But he is convinced human behaviour needs to change dramatically in order to tackle carbon emissions. ''We have to generate energy by means that don't involve fossil-fuel emissions. Essentially, we need to de-carbonise the economy over the coming decades. Part of our set of tools for doing that needs to be a price signal; we need a price on carbon.''

Dr Canadell said keeping world temperature rises to 2 degrees will take a rallying of will and effort akin to that seen during wartime, but it need not be seen as a bad thing. This is the new industrial revolution, he said, an incredible opportunity to create new jobs and industries.

''It is exciting, because the energy systems we are looking at into the future are much more complex than what we have so far, which is basically digging up stuff from the ground and burning it.''