A colossal project in China is attempting to plant microscopic particles in our atmosphere to induce the formation of clouds ready to rain down on the ground – over a space spanning nearly 2 million square kilometres. The aim is to “remote control” the weather of the Tibetan region as a way of ensuring water supplies in many of its lands are topped up. And it’s a big deal for the local citizens, whose regions are plagued by drought.

Turning particles into rain

Cloud seeding – to use the technical term – refers to techniques designed to alter the nature of precipitation through the dispersion of chemical substances which serve as condensation “nuclei”.

The first stage in the plan is to create a network of infrastructure – owned by the China Aerospace Science and Technology Corporation – on the steep slopes of the Tibetan mountains. Similar to forges, these buildings would burn solid fuels before releasing these as spray into the atmosphere. During the process, miniscule particles of silver iodide are formed and – once released – these particles are capable of attracting droplets of water vapour naturally present in the atmosphere, speeding up the condensation process. The end result? A much-needed rain shower for the parched land.

Cloud seeding: the current picture

This is not the first time a project like this has been discussed. Cloud seeding actually made its first appearance back in 1950s’ USA, where studies were carried out into the use of microscopic silver iodide or dry ice particles to try to spark small snow showers.

Since then, other experiments have taken place, some focusing on land-based cloud seeding but the majority exploring the idea of using aeroplane contrails, in the hope of gathering scientific data and results on the possibility of making the technique usable on a large scale. However, some such experiments resulted in the rise of some pretty wild conspiracy theories.

Today’s most modern systems also use particles of magnesium, sodium chloride (common table salt) and potassium, with over 50 countries currently undertaking testing and practice runs on a small scale.

The Chinese case

China also has experience in this field – in fact, they are the most active country in the world in the industry. Back in 2011, China was already spending ten times more than the USA on cloud seeding. Five years ago, the Chinese claimed they were generating 55 billion tonnes of artificial rain per year thanks to release systems installed on aircraft and rockets. Now, the country is planning to increase that figure by five times and build permanent facilities on the ground.

According to predictions, the project would cover over 1.5 million square kilometres (three times the size of Spain, to give you an idea) using over 500 chimneys distributed across Tibet, Xinjiang and other mountainous areas. Researchers working on the project believe that the increased rainfall and cloud cover at high altitude would be enough to reinvigorate the waterways snaking across China, India and Nepal – thus making these areas lusher and less vulnerable to aridity.

A spot of analysis

The plan, though undeniable ambitious, has thrown up a few issues.

On the one hand, some people are extremely sceptical as to the efficacy of these systems. Indeed, there is little evidence to show that the various types of cloud seeding processes actually work.

Many of the tests conducted in the field around the globe have been done exclusively in laboratories, which does not guarantee success in the real world. In meteorology, it is very difficult to constantly replicate processes while keeping all the various different parameters under control.

On the other hand, some criticise those behind the project for “wanting to play God”. Yet many scientists hit back that affecting the weather is certainly nothing new for human beings – we do it with our industrial activities and transport, for example. And we certainly make our presence felt to nature by using fertilisers and altering the course of rivers and streams.

One thing’s for sure, however: the Chinese project is – and will remain – the subject of some debate.