Geir Braathen of the World Meteorological Organization says carbon dioxide was up the most in 2007, one-half percent, with methane and nitrous oxide rising by lesser amounts.
Braathen says that it was the first time in a decade that the concentration of methane in the atmosphere has increased.
The data, taken from the WMO's measurement of atmospheric gases by observatories located in more than 65 countries, was published today in the annual Greenhouse Gas Bulletin, the fourth such compendium.
He said Tuesday that it is too soon to say what caused the increases.
The use of fossil fuels (such as oil, coal and natural gas) emits carbon dioxide and other greenhouse gases into the atmosphere. CO2 is also released through the clearing of land and deforestation. Since the mid-18th century, CO2 concentrations in the atmosphere have increased 37 percent.
About 60 percent of methane is the atmosphere is produced by human activities (fossil fuel exploitation, agriculture, biomass burning, landfills and ruminant farm animals), while natural sources (i.e., wetlands) are responsible for 40 percent.
A U.N. panel has warned that continued increases of greenhouse gases will have catastrophic consequences, such as severe droughts and rising sea levels.
Carbon dioxide reached 383.1 parts per million (ppm), an increase of 0.5 percent from 2006. Concentrations of nitrous oxide also reached record highs in 2007, up 0.25 per cent from the year before, while methane increased 0.34 per cent, exceeding the highest value so far (hich was recorded in 2003).
Because greenhouse gases (once emitted) persist in the atmosphere for decades, their effect on global warming is long-term. According to today's report, the total warming effect of all long-lived greenhouse gases was calculated to have increased by 1.06 percent from 2006, and by 24.2 percent since 1990.
Meanwhile, it was announced that levels of chlorofluorocarbons (CFCs), which contribute to the shrinking of the Earth's ozone layer, continue to slowly decrease. This is a result of CFC emission reductions which were successfully enacted under the 1987 Montreal Protocol, a global effort to reduce chemicals affecting the ozone layer.
Efforts For New Climate Treaty
United Nations meetings in Poznan, Poland next month are aimed at building the outline of a new global warming treaty. The pact (to replace the expiring Kyoto Protocol) is meant to be completed in December 2009 in Copenhagen.
Europeans want the Copenhagen treaty to reduce by 20 percent the amount of CO2 discharged into the atmosphere from transportation, industry and power generation.
However, last week the U.N. said that, showing how urgently a new deal to curb global warming is needed.
European Union leaders agreed last year that a fifth of the energy used by the 27-nation bloc by 2020 will come from renewable sources, like solar and wind.
Poland, Italy and others want to water down the commitments made last year.
President Bush declined to ratify the Kyoto Protocol. China also refused to sign, meaning the world's two largest emitting nations are not included in the treaty, which expires in 2012.
Discussions at the climate conference beginning December 1 in Poznan, Poland, will be based on a 2007 accord reached in Bali, Indonesia, when the United States, India and China indicated they would participate.
A partnership of environmental groups (including Greenpeace, WWF, Friends of the Earth and Climate Action Network Europe) warned the EU Tuesday that it will lose its leadership role in the climate debate if it does not live up to its promises.
U.S. President-elect Barack Obama declared this week, and aim to lower them another 80 percent by 2050.