Carbon dioxide levels in the atmosphere grew more in past 12 months than at any time in the past 56 years

Carbon dioxide levels in the atmosphere grew more in past 12 months than at any time in the past 56 years.
Measurements at the Mauna Loa Observatory in Hawaii went up by more than three parts per million(ppm) in 2015.
Scientists say the spike is due to a combination of human activities and the El Niño weather pattern.
They argue that the data increases the pressure on global leaders to sign and ratify the Paris Climate Agreement.
Mauna Loa is the world’s oldest continuous atmospheric measurement station, with records dating back to the later 1950s.