XINING -- The harsh winter winds of the Qinghai-Tibet Plateau used to worry herder Sonam Tsering in a very specific way. They would blow plastic bags away from the nearby rubbish dumps, sending them swirling through the air before settling across pastures.

"It was heartbreaking to see my pasture littered with plastic bags," said Sonam Tsering, who is from Shaliuhe township, Gangcha county of Northwest China's Qinghai province, pointing out that they had posed a potentially fatal risk to livestock, as accidentally ingesting such bags could cause death.

However, things are very different these days in Gangcha county, much to the relief of this herder: "Now, when the trash bin is full, a quick phone call ensures the waste is removed."

The change in circumstances Sonam Tsering mentioned is thanks to a shift in local waste-disposal methods. Instead of leaving garbage to degrade in nearby landfills -- it is now transported elsewhere for incineration.

When it comes to disposing of non-recyclable waste, there are two primary options -- landfills and incineration. In Sonam Tsering's hometown, situated on the northern shore of the pristine Qinghai Lake, this change reflects the efforts of local policymakers to find an optimal waste disposal solution that aligns with their broader goal of conserving the environment in this ecologically sensitive region.

Qinghai Lake, situated in the northeastern section of the Qinghai-Tibet Plateau, is one of the world's highest plateau lakes -- and plays a crucial role in maintaining ecological security in Northwest China.

Over the past two decades, more than ten landfills have been established in the area around the lake to dispose of household waste. Most of these landfills are located in ecologically sensitive areas, such as grasslands and valleys around Qinghai Lake. Data shows that by the end of 2023, the total area of landfills in the lake region had exceeded 500,000 square meters -- with insufficient remaining capacity.

Waste management, notably, presents distinct challenges on the Qinghai-Tibet Plateau. Landfills in this lake area are situated near natural grasslands, and the plateau's very cold temperatures and low oxygen levels significantly extend the waste degradation period. Moreover, some landfills reach full capacity before their planned lifespan, while others continue to operate beyond their intended lifespan.

During the windy winter and spring months, plastic bags from the landfills were often scattered around nearby pastures.

In 2023, with the launch of Qinghai province's first large-scale waste incineration and power generation project in its capital, Xining, the counties surrounding Qinghai Lake gradually adopted a new waste management system. This system involves collecting waste from villages and transporting it through township and county-level areas before it reaches Xining for incineration.

From June 2024 to early May of 2025, the lake area transferred almost 2,000 truckloads of household waste -- amounting to nearly 30,000 tonnes. Incineration of this waste has, meanwhile, generated around 15 million kilowatt-hours of electricity.

Purifying steps are taken to ensure safe disposal at incinerators. Waste is first fermented and then incinerated at temperatures exceeding 850 C, which effectively breaks down harmful substances, according to Wang Yongpeng, head of the garbage incineration and power generation project in Xining.

The flue gas generated during incineration is treated through processes like de-acidification, absorption and dust removal -- to ensure emissions comply with environmental standards, Wang added.

This overhaul of waste disposal is just one of a series of ecological conservation efforts aimed at protecting the Qinghai Lake region. Thanks to these efforts, the ecological environment of Qinghai Lake has improved, while biodiversity has been rapidly restored in recent years.

The lake has seen rising water levels and an expanded water area for 20 consecutive years. Satellite data obtained in September 2024 showed that Qinghai Lake's water body spanned 4,650.08 square kilometers -- sustaining two decades of continuous expansion since 2004.

In terms of waste disposal, the move from landfills to incineration in this lake area also aligns with the country's broader trend. In the past, China used landfills as a primary method of garbage disposal. Fueled by an intensifying environmental consciousness, China has transformed its waste management paradigm over the past two decades -- by promoting cleaner and more efficient waste incineration technology.

Today, over 1,000 large-scale incineration plants operate across China, processing more than 1.1 million tonnes of waste daily -- equivalent to filling 440 standard Olympic-sized swimming pools (each holding 2,500 tonnes of water).

Joining the trend, the Qinghai Lake region is forging new paths for waste disposal in high-altitude and low-oxygen areas both in China and globally.