The latest data from the World Meteorological Organisation (WMO) shows the amount of greenhouse gases in the atmosphere reached record levels last year.
The UN's specialist weather agency on Wednesday said the warming effect on the climate caused by heat-trapping gases in the atmosphere had increased by a third between 1990 and 2012.
Carbon dioxide, mainly from fossil fuel-related emissions, accounted for 80 per cent of that increase, though spikes in methane and nitrous oxide concentrations also played a part.
The agency also found the atmospheric carbon dioxide grew more quickly last year than its average increase over the past ten years, showing an accelerating trend.
Limiting the impacts of global warming would require sustained cuts to greenhouse gases, and the time for action was now, the WMO said in its latest Greenhouse Gas Bulletin.
CSIRO's Dr Pep Canadell said the WMO findings were further evidence of the unprecedented and relentless human impact on the planet.
"The new trends in atmospheric greenhouse gases are the definitive proof of... the fact that current efforts to address climate change are not enough to stabilise the climate system," he said in a statement.
It comes after the Intergovernmental Panel on Climate Change (IPCC) found that concentrations of heat-trapping gases in the atmosphere had hit levels not seen in at least 800,000 years.
The IPCC fifth assessment, handed down in September, warned that failing to curb greenhouse gas emissions would lead to dangerously high rises in global temperatures by the end of the century.
Since the start of the industrial era, the global average concentration of CO2 in the atmosphere has increased by around 40 per cent, methane by 160 per cent and nitrous oxide by 20 per cent.
Both methane and nitrous oxide are considerably more harmful to the atmosphere that carbon dioxide.
The WMO said because carbon dioxide remains in the atmosphere for hundreds of years, the impacts of climate change would persist for centuries, even if emissions ceased today.
The WMO snapshot reports on concentrations, or what remains in the atmosphere after natural processes, not emissions, or what is released.
Only about half of the CO2 emitted by human activities remains in the atmosphere, with the rest being absorbed in the biosphere and in the oceans.