Greenhouse gas levels reached a record high in 2012, according to a new report from the UN World Meteorological Organization (WMO). The WMO's annual Greenhouse Gas Bulletin, published Wednesday, finds that the rate of global warming increased by 32 percent between 1990 and 2012, due to rising levels of carbon dioxide (CO2), methane, and other heat-trapping gases.

Carbon dioxide accounted for 80 percent of this rise, the report notes, as atmospheric concentrations of the gas reached record levels. In 2012, CO2 levels reached 393.1 parts per million, 41 percent higher than pre-industrial levels. Since the dawn of the industrial era in 1750, concentrations of methane and nitrous oxide have increased by 160 percent and 20 percent, respectively, the WMO finds.

"our climate is changing, our weather is more extreme."

"The observations from WMO’s extensive Global Atmosphere Watch network highlight yet again how heat-trapping gases from human activities have upset the natural balance of our atmosphere and are a major contribution to climate change," Michel Jarraud, secretary general of the WMO, said in a statement today. "As a result of this, our climate is changing, our weather is more extreme, ice sheets and glaciers are melting and sea levels are rising."

Today's report comes little more than a month after the UN's Intergovernmental Panel on Climate Change (IPCC) announced that humans are almost certainly to blame for the world's rising temperatures, based on a thorough review of scientific literature. The panel also found that concentrations of CO2, methane, and nitrous oxide reached levels not seen in the past 800,000 years, leading to more extreme weather patterns and rising sea levels.

"Time is not on our side."

The WMO report released today focuses on concentrations, rather than emissions, though Jarraud says that in light of the IPCC's findings, it's clear that strong action must be taken to avoid potentially disastrous consequences.

"Limiting climate change will require large and sustained reductions of greenhouse gas emissions," the secretary general said. "We need to act now, otherwise we will jeopardize the future of our children, grandchildren and many future generations. Time is not on our side."

World leaders will gather at a UN conference next week in Warsaw to discuss a long-awaited 2015 climate deal. Attempts to reach a broad deal stalled in 2009, when governments met at a UN conference in Copenhagen.