Greenhouse gas observation is vital because it can show how much human activities contribute to global warming and can help guide the making of emission reduction plans, a leading meteorologist said.

Zhang Xiaoye, an academician of meteorology at the Chinese Academy of Engineering, made the remark in late July when the China Meteorological Administration released the 2019 China Greenhouse Gas Bulletin.

The bulletin included global data monitored by China and recorded the global carbon dioxide level at about 411 parts per million in the air, the highest since record-keeping began in the 1990s and starkly higher than the 280 parts per million of the preindustrial period before 1750.

The bulletin included data for the three main greenhouse gases: carbon dioxide, methane and nitrous oxide.

"The bulletin showed that increased greenhouse gas density in the air equaled the remaining amount of emissions discharged into the air by human activities," Zhang said.

The "remaining amount" refers to about 44 percent of greenhouse gases previously discharged by humans, after the rest is absorbed by ocean and land, he said.

"Extensive observations globally proved the correlation between emissions and gas density, so we can deduce the emission amount through the gas data," he said.