Adventures in the Anthropocene. Gaia Vince

of the fish in the Mekong begin their life in the Tonle Sap – it is the most productive inland fishery in the world, supporting up to 4 million people and providing three-quarters of the country’s fish catch. It means that even though Cambodians are among the world’s poorest people, they are some of the best fed.⁸

      By November, the end of the rainy season, the brimming lake actually causes the river to flow backwards. This annual flow reversal is cause for great celebration in Cambodia and occurs in the stretch outside of the king’s palace, to much festivity. The upstream dams would halve this annual pulse (perhaps spelling the end of the famous reversal), and dramatically impact the ecosystems it supports.⁹ Around half of the river’s water would be held in storage over the border in Laos, and instead of an annual flood, the waters would be released at the whim of dam managers, who can override the natural cycle at the push of a button.

      In the early morning, I slip down a rain-slicked muddy bank of the Mekong to board a rusty ferry downriver to Vietnam. There are few other passengers – most people are using the new highway. How different the river is now from the liquid crease folded into the mountains of northern Thailand. Here, the Mekong is fat and deep and hurtles along to the South China Sea like a migrating fish on its urgent journey south.

      At the border the river splits into islands and channels – the Vietnamese call the Mekong the dragon with nine tails. People here live closer than ever to the Mekong, in stilted houses that reach the bank via wobbly boards tied together with ropes. Next to the floating café where I slurp my noodles is one such house, with a young family that is bathing in the river: mother, father and then two toddlers. Next the laundry is washed, sloshed in the river and slapped on their bamboo deck. Then it is the bowls and plates that must be rinsed. The river also supplies their food. A net suspended under the house holds a fish farm, and they feed the fish through a hole in the living-room floor.

      Several new bridges are mid-construction on this stretch, but for now people cross from one side to the other on little canoes, rowed by women in pyjamas and conical straw hats against the sun. Further downstream I reach Can Tho, the capital of the Mekong Delta, where this once-glacial water spills into the South China Sea. The region is home to 17 million people, who depend largely on farming rice and fishing. Here, humanity has already changed the river: fish numbers are declining because of overfishing, pollution and sediment build-up (as a result of river extractions that reduce the Mekong’s ability to flush sediments into the sea). And the river is also turning salty as the sea level rises (owing to global warming), producing a measurable salinity of four parts per thousand as far as fifty-six kilometres inland.¹⁰ Many farmers are having to switch from rice farming to shrimp farming, which involves higher upfront costs and aquaculture skills that they do not have. The government is responding by filling in the smaller channels and moving ancient fishing communities into factory work.

      I rise early to boat to the famous floating markets. I was last in this region in 1995, and I remember the markets as an enormous medley of hundreds of boats, spilling over with vibrant produce. This time they are smaller with few boats. Buying and selling is still under way, but in this region the bridges are now built, and floating markets will soon disappear completely, replaced by large land-based ones for the new motorbike-owning community.

      The direct relationship people have with their rivers is disappearing as these water sources are diverted and dry up. But our dependence on them is as vital as ever – access to water is already a leading cause of conflict around the world and, although potential water wars have been avoided through river-sharing agreements and treaties, 60% of the world’s 276 international river basins lack any type of cooperative management. However, in many places conflict is being averted by water-rich countries trading with their less-endowed neighbours, and this will become increasingly important into the Anthropocene. Nearly the entire Paraguayan economy depends on selling hydroelectricity to Brazil. The two neighbours share the Paraná River, which is dammed at Itaipu. Other thirsty countries are considering buying water from their neighbours. The US, for example, plans to buy water from Mexico (piped from two planned desalination plants at Playas de Rosarito) and Canada. Analysts predict that by 2020 the world water market will be worth $1 trillion, mainly through a growth in demand in Asia and South America.¹¹

      Humans are also distributing water around the world through ‘virtual water’ trade – the trade in goods and services that are produced using water. Most of this – 92% of fresh-water consumption – is embodied in agriculture.¹² So, for example, more than three-quarters of the water used by Japanese people originates outside the country in, say, beef bought from Australia. The water footprint of an average US citizen – which at 2,840 cubic metres per year is more than double that of the Japanese – is 80% home-grown, with the bulk of the remaining 20% coming from China’s Yangtze River basin. As nations become more water-stressed, however, a new strategy is developing. Governments are buying up foreign land that is rich in water, or angling for a controlling stake in how that water is used. All of these acquisitions are occurring in developing nations and most in places where there is poor governance, corruption, little regulation and where local people have few rights to their own land and resources. Saudi Arabia, South Korea, China and India have all bought up huge tracts of land across Africa, usually in the poorest countries’ most fertile zones and river basins, to grow crops for export back home. The Nile River, for example, is now under pressure not just to feed its resident human population, but also those in other continents who have purchased parts of Sudan.