Carbon dioxide reached its highest level in recorded history last month, at 410 parts per million. This amount is highest in at least the past 800,000 years, according to the Scripps Institute of Oceanography at the University of California, San Diego.

When records started in 1958, the levels were 315ppm. Since then, there has been nearly a 30 percent increase, with levels cross the 400ppm mark in 2013 and now this. Before the beginning of the Industrial Revolution, the levels of CO2 fluctuated but never crossed 300ppm.

“We keep burning fossil fuels. Carbon dioxide keeps building up in the air,” geochemist Ralph F. Keeling, who currently directs the Scripps CO2 program, said in a statement. “It’s essentially as simple as that.”

Carbon dioxide is called a greenhouse gas for its ability to trap solar radiation and keep it confined to the atmosphere. It is the most prevalent among all greenhouse gases produced by human activities, attributed to the burning of fossil fuels.

The increase in gases such as carbon dioxide, methane and nitrous oxide is fueling climate change and making “the planet more dangerous and inhospitable for future generations,” the World Meteorological Organization has said.

The burning of the oil, gas and coal for energy releases greenhouse gases such as carbon dioxide and methane. These gases have caused the Earth’s temperature to rise over the past century to levels that cannot be explained by natural variability.