Current climate pledges are not enough to stop global warming, UN says

Pollution is still rising despite world pledges to cut carbon emissions and more action is needed to rein in climate change, a UN report says.

The Emissions Gap report is the fifth yearly analysis that examines how countries are doing and lays out the path toward keeping the average rise in global temperature below two degrees Celsius over the next century.

The report by the UN Environment Program and the World Resources Institute said the planet must aim for global carbon neutrality by mid-to-late century to head off the worst effects of climate change.

"There is still a significant gap between where emissions are going and where they need to be by 2030 if we're going to limit warming to less than 2 degrees (Celsius)," said Taryn Fransen, project director of the Open Climate Network at the World Resources Institute.

The report calls for global emissions to peak in the next 10 years before beginning to decline by 2030, as more forests are planted to absorb carbon, and more economies pursue cleaner alternatives to fossil fuels.

To avoid the devastating effects that a hotter planet may bring in terms of food shortages, job loss and storm damage, the report calls for "global carbon neutrality" - or a net zero of human-caused C02 emissions - by sometime between 2055 and 2070.

Then, global greenhouse gas emissions should be at least 50 per cent lower by 2050, said the report.

After that, total global greenhouse gas emissions - not just carbon - need to shrink to net zero sometime between 2080 and 2100.

More than 90 countries have made voluntary pledges and commitments to cut emissions.

Five countries that are party to the UN Framework Convention on Climate Change - Brazil, China, the European Union 28, India and the Russian Federation - are on track to meet their pledges, the report said.

Australia, Canada, Mexico and the United States "are likely to require further action and/or purchased offsets to meet their pledges" for 2020, it said.