World Meteorological Organization, a branch of the UN, has reported that Greenhouse gasses in the atmosphere reached a record high in 2013. The report fouses on the fact that the Earth's ability to absorb greenhouse gasses like CO2 may be reaching a saturation point that, if exceeded, could greatly exacerbate problems caused by global warming. 

"the concentration of carbon dioxide in the atmosphere actually increased last year at the fastest rate for nearly 30 years," said Michel Jarraud, the group's secretary-general, in a statement. This increase is the largest increase of carbon dioxide in a single year since 1984.

"We must reverse this trend by cutting emissions of CO2 and other greenhouse gases across the board," said Jarraud. "We are running out of time."

Between 1990 and 2013, the energy in the atmosphere increased by 34 percent, with arbon dioxide 42 percent higher than the level in the pre-industrial era. Methane and nitrous oxide were 153 percent and 21 percent higher than pre-industrial levels, although their quanity of those gasses in the atmosphere is much lower than carbon dioxide.

About a quarter of carbon dioxide emissions into the atmosphere are absorbed by plants, while another quarter dissolves into the ocean. The report warns that the ability of plants and oceans to keep on absorbing excess greenhouse gases may be slowing as those systems approach a saturation point.

The preliminary data suggests the record high level of carbon dioxide "was possibly related to reduced CO2 uptake by the earth's biosphere in addition to the steadily increasing CO2 emissions," the organization wrote in a statement. 

Jarraud warned "past, present, and future CO2 emissions will have a cumulative impact on both global warming and ocean acidification. The laws of physics are non-negotiable." This level of CO2 saturation is making the oceans more acidic, which is harming coral, which itself is responsible for a large chunk of CO2 absorbtion. Studies extrapolating from the fossil record suggest that the rate of acidification is now "unprecedented, at least over the past 300,000 years," the WMO said.

"The inclusion of a section on ocean acidification in this issue of WMO's Greenhouse Gas Bulletin is appropriate and needed. It is high time the ocean, as the primary driver of the planet's climate and attenuator of climate change, becomesa central part of climate change discussions," said Wendy Watson-Wright, Executive Secretary of the Intergovernmental Oceanographic Commission of UNESCO.

"There is a lot of year-to-year variability in the carbon sinks, so I don't think we can say much about their response based on their behavior over one year," Corinne Le Quéré of the Tyndall Centre for Climate Change Research and University of East Anglia in the U.K., told National Geographic.

Le Quéré's colleague Róisín Moriarty of the Tyndall Centre added that emissions are steadily rising and that climate models predict carbon dioxide will likely continue to dissolve into the oceans until at least 2050.

Gavin Schmidt, a climate scientist with NASA's Goddard Institute for Space Studies, says that "it is very hard to say" whether the Earth's natural carbon sinks are becoming saturated with carbon dioxide.

"There is a lot of interannual variability in uptake, related to El Niño-La Niña cycles and weather changes over the terrestrial regions," said Schmidt. "You are going to need to look over a longer time period."

From the Washington Post "The WMO's data for 2013 shows the global average level of atmospheric carbon at just under 400 parts per million, about 40 percent higher than in ­pre-industrial times and higher than in any other period in at least 800,000 years. The symbolically important threshold of 400 parts per million - described by scientists as the level at which more dramatic climactic impacts become likely - will probably be crossed in the next two years"

ThinkProgress: "As the WMO notes, the ocean currently soaks up about a quarter of human-caused CO2 emissions, which has reduced the amount of observed carbon in atmosphere. However, the WMO report says the ocean's capacity for absorbing carbon is decreasing, which will eventually lead to a speed-up in atmospheric warming. Indeed, the ocean's ability to hold carbon is only 70 percent of what it was at the beginning of the industrial revolution. By the end of the twenty-first century, it could be reduced to 20 percent, the WMO said."

This January, the Yale Project on Climate Change Communication found that 23 percent of Americans do not believe that global warming is happening, up 7 percent.

"If the oceans and the biosphere cannot absorb as much carbon, the effect on the atmosphere could be much worse," said Oksana Tarasova, a scientist and chief of the WMO's Global Atmospheric Watch program, which collects data from 125 monitoring stations worldwide.

The organisation's annual report on greenhouse gas levels was released ahead of a climate summit of world leaders at this year's UN General Assembly meetings in New York, scheduled for September 23, President Obama will meet with chief executives from dozens of other countries to discuss ways to lower industrial emissions of carbon dioxide, methane and other gases blamed for heating up the planet.

The report also noted that greenhouse gasses were approaching 400 parts per million mark, the threshold where dramatic climate chage related problems are likely to occur, will be crossed in the next two years.

"It's the level that climate scientists have identified as the beginning of the danger zone," said Michael Oppenheimer, a Princeton University professor of geosciences who was not involved in the WMO report. "It means we're probably getting to the point where we're looking at the 'safe zone' in the rearview mirror, even as we're stepping on the gas."