The UN World Meteorological Organization (WMO) said Monday that greenhouse gases rose to a symbolic milestone last year, taking climate change into a new phase which could last generations even if governments act to curb human activity that leads to global warming.
"The year 2015 ushered in a new era of optimism and climate action with the Paris climate change agreement. But it will also make history as marking a new era of climate change reality with record high greenhouse gas concentrations," WMO Secretary-General Petteri Taalas said in a statement.
"The real elephant in the room is carbon dioxide, which remains in the atmosphere for thousands of years," Taalas added.
An observatory at Mauna Loa in Hawaii, the main measuring station with records dating back to 1958, "predicts that carbon dioxide concentrations will stay above 400 ppm for the whole of 2016 and not dip below that level for many generations," the WMO said.
Carbon dioxide levels will continue rising unless the world stops burning fossil fuels and starts planting trees, said WMO's atmospheric environment research chief Oksana Tarasova. "The technology is there. It's just human will. If we want we can do it," she said, recalling Europe's successful efforts to combat acid rain by eliminating sulfur and nitrogen emissions. "You can bend the curve. If you take an action and you sign a treaty and everybody follows their commitments. It's not magic."
Man-made warming is blamed for causing heatwaves, downpours, droughts and rising ocean levels. Worldwide in 2015, average levels of carbon dioxide were at 400.0 ppm, up 2.3 ppm from 2014, the WMO said.
A powerful El Nino weather event, which warms the eastern Pacific Ocean, was also probably driving global rises in 2016. The El Nino is linked with more droughts and wildfires in the tropics, meaning less vegetation to absorb carbon dioxide.
A 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. Carbon dioxide levels were 144 percent of pre-industrial levels of 278 ppm, methane levels were 256 percent of pre-industrial levels at 1,845 parts per billion and nitrous oxide levels were 121 percent at 328 parts per billion, the UN said.
jar/rs (AP, Reuters)