Phnom Kampong Trach, a karst mountain in southern Cambodia’s Kampot province, close to the border with Vietnam, towers over rice paddies and pepper plantations like a slumbering dragon. Local people have a long and intimate relationship with the massive limestone outcrop and its numerous caves. This is where they collect guano – bat droppings – to fertilise their crops. This is where their spirits live. And in times of war, this is where they have taken shelter from bombs and destruction.

To enter the massive landmark’s gloomy interior, we clamber through a cavity that Ken Sam An, director of the local forestry and eco-tourism association, tells us is called “the dragon’s neck”. Over millions of years, water has dissolved and sculpted the limestone here – the remains of an ancient coral reef – into otherworldly shapes. Ken Sam An names them in turn (“the elephant’s tongue”; “the mushroom god”; “the white diamond elephant”).

We pass a monk chanting by a shrine and climb the 100 or so steps to a natural balcony. A cowbell chimes gently from below. Then, suddenly, an explosion sends a shudder through the rock and Ken Sam An points out a cliff, perhaps a dozen kilometres away, that has been torn in half.

Is Hong Kong’s third runway using ethically sourced sand?

“It breaks my heart,” he says. “If they continue blowing up the hills at this rate, they will all soon be gone.”

The reason for the environmental destruction is the need for concrete, the essential ingredient of urban development.

In just a handful of years, the construction industry has grown to become Cambodia’s second largest, after manu­facturing. The capital city of Phnom Penh, once praised as the “Pearl of Asia”, now resembles one gigantic construc­tion site, and old colonial neighbourhoods built by the French are being overwhelmed by high-rise towers.

Asia as a whole, in fact, is currently spending more on construction than all of Europe and the United States combined, and Cambodia is in overdrive. Foreign demand for property has spurred construction mania, and leading real estate consult­ancy Knight Frank expects the number of condominiums across the country to triple in the coming two years.  

For botanists, the resulting demand for cement represents a crisis: Kampot’s little-explored limestone hills are teeming with plant species that don’t exist anywhere else in the world, and their extinction now looms even before a full inventory of their number has begun.

Dusk heralds a remarkable performance at the nearby hill known as Phnom La’ang. Once the daylight has faded, thousands of black creatures dart out from a cave, quickly weaving into a thick spiral that twists and undulates over the fields.

The bats keep coming for more than an hour, the huge colony being central to the local ecosystem. The bats’ reeking guano crawls with insects that are food for other creatures, many of which are – owing to Phnom La’ang’s isolation – unique to the area. Researchers have likened Kampot’s hills to arks providing a variety of unusual fauna and flora shelter in which to evolve in relative safety.

Here, scientists have discovered tropical plants that behave like desert species, including a poinsettia with cactus-like characteristics. Dutch botanist Jaap Vermeulen has completed an inventory of snail shells – a good indicator group to assess biodiversity on limestone hills. On Phnom La’ang, he discover­ed nine species found nowhere else – a Southeast Asian record. “This illustrates what factories of new species these hills are,” Vermeulen says.

Now, the hill may be incorporated into what will be one of Asia’s tallest structures.

Thai Boon Roong, the Cambodian company that owns Phnom La’ang and has built a cement plant at its base, has been given the go ahead to build the Thai Boon Roong Twin Trade Centre – a skyscraper in Phnom Penh with two 560-metre-tall towers – prompting Prime Minister Hun Sen to declare that “the sky is now the limit” for the country.

Although many doubt that the project will ever be completed, believing it to be simply a publicity stunt, it is indicative of the kind of projects that are currently favoured by Cambodian developers, though chiefly driven by foreigners.

Vann Molyvann: the unsung hero of Phnom Penh architecture

The real-estate boom in Phnom Penh began to take off in 2010, when foreigners were first allowed to buy flats above the first floor (foreigners are still not allowed to buy ground-floor units or land in Cambodia unless doing so is as part of a joint venture with a local partner). Today, models of upcoming projects can be viewed in air-conditioned show­rooms across the city. They carry English names such as Imperial Crown Condominium, The Penthouse Residence and 88 Suites. The brochures, however, are in Chinese.

“Most buyers come from China,” says Sam Ponleu, client manager at The Parkway, a new development in the Tuol Kouk district of the capital. An estimate by independent Bangkok-based financial analyst George McLeod, formerly of PwC Consulting (Thailand), puts the proportion of investors from China at 25 per cent.

The attraction is undeniable. Cambodia is affordable compared with many other Asian countries, it deals in a strong currency – the US dollar – and boasted an average annual gross domestic product growth rate of 7.6 per cent between 1994 and 2015, according to the World Bank. Also, financial regulations are famously lax, making the country a popular destination for illicit money. The deputy commissioner of police in the coastal Preah Sihanouk province recently warned that Chinese money laundering had become a problem.

“Money doesn’t just flow from China without a reason,” says Christopher Balding, associate professor of business and economics at the Peking University HSBC Business School, in Shenzhen. “There are valid concerns that the investment into real estate in Cambodia is dirty money.”

Beijing’s response has been two-pronged.

On one hand, Xiong Bo, China’s ambassador to Cambodia, has called such allegations “fake news”. On the other, he has said that the Chinese government will not tolerate the establishment of Chinatowns or Chinese casinos, and that China will collaborate with Cambodian authorities on the issue.

It’s a strange fact of our time that, as the world is living through its sixth mass extinction, science has given up. Buddhist philosophy at least values the conservation of all life
Andrew McDonald, a University of Texas Rio Grande Valley botanist

A continued boom, however, is very much in Beijing’s interests, giving China’s construction sector, which is understimulated at home, opportunities to build. In 2016, 30 per cent of all foreign investment into Cambodia came from China, and at a meeting between Hun Sen and Chinese President Xi Jinping in December, an additional US$7 billion was pledged by Chinese companies. The fact that Chinese state-owned enterprises are involved in the Thai Boon Roong Twin Trade Centre has convinced some analysts that the skyscrapers will actually materialise.

China’s “Belt and Road Initiative” has spurred much of the construction boom elsewhere in Asia, too. Last year, India committed to building 83,000km of roads before 2022. Fourteen skyscrapers, each to stand more than 200 metres tall, are planned for Jakarta, the capital of Indonesia. And Philippine President Rodrigo Duterte has launched a “Build, Build, Build” campaign and ambitious infrastructure spending spree.

Taken together, these initiatives suggest concrete con­sumption might rise to levels last seen with China’s own construction boom.

According to the Global Cement Report, produced by leading cement manufacturing sector portal CemNet.com, China consumed more concrete in 2015 alone than the US did in all of the 20th century. Last year, global demand for concrete led to 3 billion cubic metres of limestone being pulverised, as well as about eight times as much sand and other stone.

The green schools leading the way for sustainability in Hong Kong

This poses an enormous environmental challenge. The production of cement, the binding agent in concrete, accounts for between 8 and 9 per cent of the world’s total carbon dioxide emissions, according to a 2016 report from the European Commission’s Joint Research Centre. About half comes from the burning of fossil fuels to heat the limestone to temperatures of up to 1,450 degrees Celsius, and the other half from the resulting calcination process.

The United Nations’ Intergovernmental Panel on Climate Change (IPCC) has acknowledged that reforms in cement production are crucial to achieve the climate goals set out in the 2015 Paris Agreement. The IPCC has recently praised the industry for phasing out fossil fuels, experiment­ing with cement substitutes, and capturing CO2 with filters and storing it underground. But these efforts have their own problems, such as the risk of fissures when pumping massive amounts of CO2 into the earth.

Among the most promising concrete substitutes is wood. Research has minimised traditional risks associated with the material, such as fire and degradation, and prefabricated segments can be assembled into robust multi-storey build­ings in half the time required when building with concrete, and with a fraction of the noise. In 2015, a 14-floor wooden structure was built in Norway. The following year, an 18-storey tower went up in Canada, the country that leads in wood construction.

Peter Moonen, sustainability manager at the Canadian Wood Council, says the material is now a realistic prospect in areas previously viewed purely as concrete territory, such as building frameworks.

“The evolution resembles the time when [French civil engineer Gustave] Eiffel built his tower in Paris and raised awareness for the potential of iron and steel,” he says, “only we’re doing it for wood.”

World’s tallest wooden skyscraper planned in Tokyo

One benefit of using wood is that it results in the replant­ing of forests, which leads to the absorption of more CO2 than when forests are merely preserved.

“Naturally, we need to protect key biotopes, but the idea that we are saving the climate by preserving all forests is completely wrong,” says Magnus Wålinder, professor in building materials at the KTH Royal Institute of Technology, in Stockholm, Sweden. “Wood is indisputably better than concrete from an environmental standpoint. To think that we are not paying attention to which materials our homes are made of is quite horrible.”

Moonen agrees with Wålinder, and argues that the future lies in hybrid solutions, with each material being used where best suited.

“The cement and concrete lobby is adamantly opposed to wood,” Moonen says. “But a developer who doesn’t contem­plate the wide array of materials that exist today is like a person who claims to be a gourmet chef, but doesn’t under­stand a thing about vegetables.”

Cambodia, however, has already chopped down the majority of its woodlands, and activists’ attempts at forest preservation have been fraught with danger (the country’s most prominent environmental activist, Chut Wutty, was killed under mysterious circumstances in 2012, when stopped by military police while he was investigating illegal logging).

The people working to preserve the country’s limestone hills today number only about half a dozen.

Steve Bernacki, an American consultant working with the International Union for Conservation of Nature in Cambodia, is trying to persuade Cambodia’s Ministry of Environment to give five hills protected status, and Thai Boon Roong to move its cement plant from Phnom La’ang, which he calls a “national jewel”.

In Cambodia, civil society is rising up against forced evictions, land grabs

Ana Komericki, a Phnom Penh-based Croatian programme officer for British NGO Fauna & Flora International, is working to engage the cement industry in more environ­mentally sound practices. And Andrew McDonald, a University of Texas Rio Grande Valley botanist who is leading a project to inventory the plants on the hills, is about to found an organisation involving Buddhists, who have been meditating and building shrines in the hills for centuries.

“It’s a strange fact of our time that, as the world is living through its sixth mass extinction, science has given up,” McDonald says. “Buddhist philosophy at least values the conservation of all life.”

While the fight to save the karst mountains drags on, concrete’s other core component – sand – is also being exploited, with dredgers con­tinually working the Bassac River just outside Phnom Penh.

Sok Cham watches the dredging from a doorway that, until a month ago, led to his bathroom, kitchen and backyard. One night, it all tumbled into the water, as did land and other structures belonging to his neighbours. The debris still litters the newly located riverbank.

An inspector sent by the government told the villagers that the erosion had been caused naturally and accused them of not building their houses properly.

“We were enraged because the government didn’t assume responsibility,” Sok Cham says. “My wife has lived here all her life and she never had these problems. Everyone knows the dredging caused the erosion.”

The villagers have arranged protests against the dredging with the help of local environmental NGO Mother Nature. However, in the past half year, after having filmed the dredgers, two of the organisation’s members have been jailed. What’s more, the main opposition party in Cambodia has been banned, independent media has been shut down and the most vocal government critic, Kem Ley, murdered. While many countries have turned their back on Hun Sen because of his increasingly despotic rule, China remains supportive.

Alejandro Gonzalez-Davidson, a Spaniard who co-founded Mother Nature, was deported to Thailand three years ago after the Cambodian Ministry of the Interior claimed he had abused his NGO’s status by setting up roadblocks while protesting against a hydropower-dam project. Gonzalez-Davidson says that some Cambodian ministries have genuinely good intentions, however.

“They understand that raping nature isn’t good for the country,” he says, “but no one dares to challenge the interests that control the natural resources. They are cartels with more power than the police.”

Chinese-backed hydroelectric dam robs Cambodian villagers of homes and livelihoods

Sarah Milne, a lecturer in resources, environment and development at the Australian National University in Canberra, likens the exploitation of natural resources by powerful yet corrupt forces in Cambodia to methods employed by the mafia.

“The use of kinship-type relationships and marriage is a way to reinforce this idea of family, and the expectations of loyalty that come with it,” Milne says. “Illicit finance is the gel that binds the Cambodian system together. Rapacious exploitation ends when the resource runs out, or when it becomes politically not feasible to continue.”

Gonzalez-Davidson aims for the latter: to create a situation in which such exploitation is no longer possible.

“We mobilise local communities, spread videos and promote tourist visits, especially by Cambodians,” he says. “If locals start taking pride in their beautiful and unique nature, and then film it with their smartphones, you will create headaches for the ones wishing to cause ecological harm.”

Back in Kampot, in 2008, the provincial government named Phnom Kampong Trach an eco-tourism destination. Ten years later, somewhere deep inside the slumbering dragon, Ken Sam An illuminates a terracotta-hued cave wall with light from his mobile phone.

“If this surface is wet, we know there won’t be drought in the coming season,” he says, citing local belief.

Roads to the impressive hill are not wide or flat enough to attract the tour-bus hordes just yet, so Phnom Kampong Trach has not become an Instagram-friendly karst hot spot like Halong Bay, in Vietnam, Palawan, in the Philippines or Yangshuo, in southern China. But while mass tourism would undoubtedly be a strain on the local ecology, it could also save the limestone hills from the booming Asian construction industry.

“Why blow up the mountains,” Ken Sam An asks, “when we could instead preserve them, and make money from them over and over again?”