An "explosive" new level of carbon dioxide in the Earth's atmosphere in 2015 shattered all previous records, report scientists from the the US National Oceanic and Atmospheric Administration. Data stretching back at least 800,000 years show that carbon dioxide levels are now higher than at any other time in human history — and they are rising at a record rate, said lead investigator Pieter Tans from NOAA's Global Greenhouse Gas Reference Network.

"Carbon dioxide levels are increasing faster than they have in hundreds of thousands of years," Tans said. "It's explosive compared to natural processes."

The news of the rise in CO2, the primary greenhouse gas emitted through human activities and fuels global warming, is particularly troubling now that several nations have committed to battling its increase. Data were collated at NOAA's Mauna Loa Observatory in Hawaii.

The findings reveal that carbon dioxide increased by 3.05 parts per million in 2015 — the biggest increase documented in the year-to-year tally in 56 years of research, NOAA reports. The figures also show that 2015 was the fourth successive year that carbon dioxide rose to more than two parts per million — another first.

Before 1800, the rate of carbon dioxide in the Earth's atmosphere was 280 parts per million on the average. In February 2016, the rate has been clocked at 402.59 parts per million.

The current rate of increase in carbon dioxide levels is 200 times faster than the last time the planet saw such a sustained increase — which was between 11,000 and 17,000 years ago — when there was an 80 parts per million increase during that period. Currently, according to Tans, the rate of increase is 200 times faster.

Some of the increase can be attributed to the El Nino weather pattern, but the main factor is the burning of fossil fuels such as oil, natural gas and coal, said NOAA. Rates of fossil fuel burning remain at historically high levels, releasing 10 billion metric tons of carbon into the atmosphere annually.

"The emissions are at a record high, therefore the growth rate of atmospheric CO2 is also at a record high," said Tans. Levels of the greenhouse gas were independently measured by NOAA's Earth System Research Laboratory and by the Scripps Institution of Oceanography, which came up with similar results.