The waste management sector is contributing 3 to 5 percent of global man-made greenhouse gas emissions, almost equivalent to current emissions from international aviation and shipping, according to a report released earlier today by the United Nations Environment Program (UNEP) at a press conference during the Cancun climate talks.

Emissions of methane, a greenhouse gas with a global warming potential 25 times that of carbon dioxide, from landfills in particular, represent the biggest impact on climate from the waste sector, the report said. Incineration of waste ranks second.

The report also pointed to a clear link between waste emissions and health problems.

However, the waste management sector is "in a unique position" to transition from an emission source to being a "major saver of emissions," thanks to a number of technologies currently available for producing energy out of waste, said Kaveh Zahedi, the UNEP climate change coordinator.

Joseph Alcamo, UNEP's chief scientist, told the media that cutting waste emissions would be a "fair way" in narrowing the 5-gigatonne gap between pledged emission reductions and what scientists have stated to be the ideal amount.

According to the recent Emissions Gap Report, presented by the UNEP and researchers from 25 modeling centers, a best-case scenario would see emissions fall to around 49 gigatonnes of CO2 equivalent, if all countries fully implement the Copenhagen pledges. While scientists estimate that to keep the temperature rise within 2C - compared with that of the pre-industrial era - emissions need to be as low as 44 gigatonnes in a decade's time.