Mongolia was the main source of northern China's worst sandstorms in five years from January to April, and may have contributed as much as 70 percent of the dust floating over capital Beijing, the environment ministry said on Monday.

Northern China is routinely hit by heavy sandstorms in the spring, with conditions worsened by deforestation and higher regional temperatures. It has tried to shield its major cities by planting extensive new forest known as "shelterbelts".

But with the number of sandstorms rising again since 2017, the focus has gradually shifted to China's northern neighbour, Mongolia, where a changing climate together with overgrazing and overmining have caused conditions to deteriorate.

China experienced as many as 12 large-scale sand and dust storms in the first four months of 2023, said Jiang Huohua, vice-head of the monitoring office at the Ministry of Ecology and Environment.

Over that period, 267 Chinese cities in 27 provinces and regions suffered more than 4,800 days of sandstorms, the highest in five years, he said.

"Several large-scale dust processes occurred this spring, and the major sources are mainly the Gobi desert in southern Mongolia and sand sources in our country's northwest," he added.

"Expert analysis estimates that Mongolia can contribute up to 70 percent of the dust concentrations in Beijing and more than 50 percent of the dust concentrations in northern China and other central and eastern regions," he said.

Around 77 percent of Mongolian land is regarded as degraded due to climate change and overgrazing, as per a 2021 assessment cited by the United Nations Development Programme. The country has also seen average temperatures rise by 2.2 degrees Celsius between 1940 and 2015, with rainfall plummeting seven percent over the same period, according to a 2021 scientific study.

Mongolia has vowed to plant a billion trees over the 2021-2030 period, but officials in Ulaanbaatar complained earlier this month that the government has yet to provide sufficient funding, the official Montsame news agency reported. (Reuters)