A new report has found global carbon dioxide emissions are set to reach record levels this year.

The snapshot, published in the journal Nature Geoscience, shows that after a dip in emissions last year, greenhouse gases are on the way back up.

The global financial crisis led to a 1.3 per cent reduction in greenhouse gas emissions in 2009.

The CSIRO's Dr Pep Canadell, co-author of the Global Carbon Project which produced the report, says the decline was expected.

"What we've seen with the global financial crisis as we expected to some extent, was that global fossil fuel emissions have come down by about 1.3 per cent," he said.

"If anything, the surprise has been a little that we were expecting a much bigger decline of emissions."

But that slowing has fast been offset by renewed growth in fossil fuel emissions as the global economy recovers.

The CSIRO's Michael Raupach says developing countries like China and India are driving the growth.

"Emissions are continuing to grow over the long term," he said.

"We're seeing no signs of a systematic reduction in global emissions, although there are now levelling off of emissions from developed countries.

"But emissions in developing countries are continuing to climb quite rapidly.

"We're concerned with the long-term trends of course and the 2010 forecast is a part of that."

Dr Raupach says a rise in emissions will make it difficult for the world to reach the target of limiting global temperature rise to 2 degrees Celsius.

"The growth rate in emissions is going to make it increasingly difficult for us to constrain climate change to levels of around 2 degrees of warming above the pre-industrial temperatures," he said.

But there is some good news.

Emissions from deforestation have fallen over the past decade by 25 per cent.

Dr Canadell says government policies in places like Brazil have slowed the global rate of landclearing.

"There has been a decline by at least 25 per cent of the emissions from land use change during this decade when we compared it with the decade of the 90s," she said.

"This is actually remarkable."