Independent: The concentration of carbon dioxide in the atmosphere has breached the symbolically important level of 400 parts per million (ppm) for the first time in 5 million years after rising at its fastest rate since records began.
Average daily CO2 levels jumped by 2.74 ppm in the first 17 weeks of 2013, compared to last year, the biggest increase since the benchmark monitoring stations high on the Hawaiian volcano of Mauna Loa began taking measurements in 1958.
Experts blamed most of the increase...