What increased that led CO2 increase

There is irresistible sign that human actions, particularly burning fossil fuels, are foremost to bigger levels of carbon dioxide and other greenhouse gases in the atmosphere, which in turn intensify the usual greenhouse effect, producing the temperature of the Earth's atmosphere, ocean, and land surface. The annual growth rate has improved since record keeping started in 1960 from fair below 1 ppm in the 1960's to additional than 2.4 ppm over the first half of the 2010's.