China has developed a space-air-ground-sea integrated monitoring network for ecological and environmental conservation, supported by roughly 150 satellites, according to the Ministry of Ecology and Environment.

At a news conference on Monday, Zhang Dawei, head of ecological and environmental monitoring at the ministry, highlighted a new satellite for high-precision greenhouse gas detection launched on April 17.

Equipped with five advanced instruments, including a lidar and a hyperspectral greenhouse gas monitor, he said the satellite enabled China to achieve, for the first time internationally, integrated active and passive greenhouse gas detection.

It is capable of conducting large-scale, high-precision monitoring of major greenhouse gases and gaseous pollutants around the world, the official continued.

"This represents a major milestone in the development of China's modern ecological and environmental monitoring system," he stressed.

Currently, the ministry serves as the lead user for eight operational environmental and atmospheric satellites and also has the ability to coordinate data from more than 140 commercial and civilian satellites, he stated.

Using multispectral sensors with rich wavebands and short revisit cycles, these satellites allow the ministry to perform full-coverage "health checks" every two months on 3.3 million square kilometers of nature reserves and key zones encircled by ecological conservation red lines, he said.

Zhang said the system also helps the ministry scan 21,000 kilometers of mainland coastline and 100,000 square kilometers of coastal waters every quarter to detect human damage or illegal encroachment.

Beyond broad-coverage scanning, Zhang said the satellites are also equipped with hyperspectral sensors for high-precision targeting.

These sensors can identify atmospheric components and quantitatively measure trace gases such as ozone, nitrogen dioxide and formaldehyde, supporting air pollution control, he noted.

"Globally, they can pinpoint methane leaks from oil and gas fields, coal mines and landfills, tracing emissions directly to specific facilities," he said.

These satellites also enable all-weather monitoring, as their radars do not rely on light sources and are not limited by adverse weather conditions.