In Beijing’s Tongzhou Number Six school, around 100 impeccably-behaved middle school students are being lectured about water.

The visiting teacher tells them that, among other things, they should take shorter showers, buy less clothes, eat less meat and drink tea rather than coffee, to help alleviate China’s water scarcity problems.

The students, aged between 12 and 15, lap up the messages. “I wasn’t aware that there are so many ways to waste water,” says Zhou Kuiru, 15. He’ll happily take shorter showers, but “eating less meat might be more difficult”.

The students are the latest to hear a talk from Thirst, an NGO that educates 12- to 24-year-olds in China about the country’s water crisis. The NGO says it has given presentations to around 500,000 students since 2013, mainly in and around Beijing, Shanghai and Chongqing. It aims to reach the 1 million mark by the end of 2017.

Trouble up north

Despite having a population of 1.35 billion – 21% of the world’s population – China only has 7% of the world’s freshwater supplies, according to the United Nations. The north of the country is more water scarce than the south. In 2015, just 100 cubic metres of water was available to each Beijing resident per year. The UN considers a region “water stressed” if this figure is below 1,700 cubic metres.

One large factor contributing is China’s rapid economic growth, fuelled by heavy industry using water for production processes. The country’s pollution problems also contribute; nearly 60% of the country’s underground water is polluted. Meanwhile, so-called “virtual water exports” – goods that require a large amount of water to make or cultivate – are often moved from water scarce Chinese regions to those with more water supplies.

In 2011, the crisis moved President Xi Jinping to give a quote that adorns Thirst’s promotional literature: “Water conservation is the fundamental way to solve our water problems. Education of citizens about China’s water crisis combined with strong environmental governance is conducive to a society focused on water conservation.”

A unique culture

Thirst aims to encourage young Chinese people to reduce their water usage and to keep tackling water scarcity a priority if they become business leaders later in life.

“Because of the one-child policy scrapped in 2015, but in place when Thirst’s students were born it’s a unique culture,” says founder Mina Guli. “Young people have a great ability to influence their parents and companies, because all the companies are now looking to China. It’s a unique group of people.”

At the crux of Thirst’s presentations are the concepts of “virtual water” and “water footprint”. The former is the amount of water used to create a product, beyond the literal amount of water it contains. For example, Thirst says it takes 15,400 litres of water to make 1kg of edible beef. A water footprint is a person’s water consumption when their use of virtual water is totted up with direct water use, such as drinking and showering.

Students are taught that eating pork instead of beef reduces your water footprint. So does buying fewer cotton T-shirts – each one supposedly uses 3,690 litres of virtual water to produce.

Dabo Guan, professor in climate change economics at the University of East Anglia, says it’s important to outline these messages to the public. “Ten years ago, nobody talked about air pollution,” he says. “But then people started to talk about it and they recognise it: they see the smog. But it’s rare to see water pollution or the drying of a river. People just aren’t exposed to it.”

Onus on industry

Thirst claims that its lectures have had largely fantastic responses from students, and this is backed up by the enthusiasm of those in the Beijing classroom. However, even if every person in China took 20-second showers and never wasted a drop of drinking water, the country’s water scarcity wouldn’t be solved, according to China Water Risk, an NGO that raises awareness of water resource problems. In 2015, just 13% of water used in China was due to personal consumption, according to the NGO.

“While it’s important to have public outreach, the majority of water use is in agriculture and industry,” says Debra Tan, the director of China Water Risk. “If you’re really going to make any difference, these sectors must move to lower water consumption. It’s down to corporate responsibility and the government.”

The government’s measures to tackle the problem include projects such as a proposed 1,000km pipeline from Siberia’s Lake Baikal to parched north-west China. In 2014 another project was inaugurated; the £48bn South-North Water Diversion, a network of reservoirs and canals that moves trillions of gallons of water annually from the south-east to the north.

The government has also focused on reducing industrial water use. Authorities have, for example, worked with Apple on its waste diversion programme, in which the firm has save 3.8bn gallons of water since 2013 in its Chinese suppliers’ factories.

Despite these measures, China’s water scarcity is “the most important environmental crisis in China,” says Guan.

As such, Guli believes that although the onus is on industry and the government to make changes, Thirst’s role is also important – and could give China a PR bump.

“There is a perception that China is a polluter, that China doesn’t care … But the reality is far from that,” says Guli. “Young people do care about the environment. By talking about it we can create a whole consumer economy that values water sustainability.”

Liu Bailin, one of the students at Beijing’s Tongzhou Number Six school, is already ahead of the curve. “Shorter showers could work,” he says. “And as for drinking less coffee than tea … I don’t actually drink either.”