Concentrations of greenhouse gases in the atmosphere have reached a new high in 2014, the UN says. World Meteorological Organization (WMO) warns that climate change is moving the planet into "unchartered territory."
The WMO said Monday that concentrations of carbon dioxide (CO2), methane and nitrous oxide once again broke records last year. CO2 levels rose to nearly 398 parts per million, from 396 ppm in 2013.
The UN panel of climate scientists estimates that concentrations of carbon dioxide, methane and nitrous oxide are at their highest in at least 800,000 years.
"Every year we say that time is running out. We have to act now to slash greenhouse gas emissions if we are to have a chance to keep the increase in temperatures to manageable levels," WMO Secretary-General Michel Jarraud said in a written statement. "We are moving into unchartered territory at a frightening speed."
The WMO chief's appeal comes ahead of a Paris summit of more than 190 countries aimed at trying to limit global warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels.
WMO chief Michel Jarraud said that CO2 can remain in the atmosphere for hundreds of years and in the ocean even longer
If CO2 concentrations double from their pre-industrial level of 280 ppm to 560 ppm, water vapor and clouds globally would hike global warming at three times the rate of so-called long-lived greenhouse gases, the WMO said.
Monday's WMO report also showed that methane, largely due to cattle farming, landfills and other human activity, has reached a new record concentration of 1,833 ppm last year.
Largely exacerbated by the coal-burning power plants, oil and natural gas for energy, global CO2 levels are now 143 percent higher than before the industrial revolution.
"We can't see CO2. It is an invisible threat, but a very real one," Jarraud said. "It means hotter global temperatures, more extreme weather events like heatwaves and floods, melting ice, rising sea levels and increased acidity of the oceans."
jar/jil (AP, AFP, Reuters)