The world is in a new era of “climate change reality”, with carbon dioxide in the atmosphere reaching a symbolic threshold which it will not fall below for many generations, scientists have said.
In 2015, for the first time, carbon dioxide levels in the atmosphere were at 400 parts per million (ppm) on average across the year as a whole, the World Meteorological Organisation’s (WMO) annual greenhouse gas bulletin reveals.
The longest established greenhouse gas monitoring station in the world, at Mauna Loa in Hawaii, predicts carbon dioxide concentrations will stay above the symbolic 400ppm for the whole of 2016 and reach new highs.