A UN climate science task force urged on Thursday the adoption of new measures aimed at providing the broadest and most accurate snapshot of carbon emissions ahead of Rio+20.

Armed with the latest scientific methods unveiled in Geneva by the Intergovernmental Panel on Climate Change (IPCC), countries will soon be able to identify more precisely than ever their biggest sources of emissions.

The greatest potential is in developing countries, where the greatest producers of carbon emissions are land use and forestry.

These areas are notoriously difficult to get data from, according to the IPCC, but it is vital to do so, given that they collectively contain more carbon than is present in the atmosphere.

Although the IPCC's Task Force on National Greenhouse Gas Inventories (TFI) has no powers to enforce implementation of its latest recommendations, there is every hope that its softly-softly approach will find plenty of takers by October 2013, the deadline for the new measures to be rolled out.

TFI co-chair Thelma Krug said: "I am very optimistic about these changes which fill methodology gaps in the 2006 guidelines.

"Taking forestry as an example, we are incentivising countries to improve their knowledge of the sector, giving them the chance to take measures to avoid major emissions."

The IPCC announcement comes ahead of the Rio+20 environmental summit due to begin on June 20.

The changes were made at the request of the United Nations Framework Convention on Climate Change (UNFCCC).For many developing countries still using the IPCC's 1996 guidelines it is a chance to update their emissions-gathering protocols.

"There's always new science that comes available to make reporting emissions more easily and effectively and this is especially important for developing countries," Krug said.

"We want to ensure countries report in a complete way, a transparent way and that these findings are consistent over time."