Yunnan

In Yunnan's northwest the Salween, the Mekong and the Yangtze run north to south within a corridor barely a hundred kilometres wide, separated by ridges but never joining. UNESCO inscribed the landscape in 2003 as the Three Parallel Rivers of Yunnan Protected Areas, meeting all four natural criteria, a distinction fewer than a handful of sites hold.

The property runs to roughly 1.7 million hectares across fifteen protected areas, from 760 metres in the river gorges to 6,740 at the summit of Kawagarbo, with more than a hundred peaks above five thousand metres between them. The gorges reach three thousand metres deep in places. UNESCO calls it an epicentre of Chinese biodiversity and among the richest temperate regions on earth.

It is also contested ground. Proposals for some twenty-eight dams have been drawn across these gorges, and boundary changes shown to an international mission in 2006 would have cut several component areas by more than a tenth, in part to make room for mining.

The numbers here are difficult to take in. Yunnan holds more than eighteen thousand higher plant species, which is over half of China's total, on four percent of its land. A 2020 study from the Kunming Institute of Botany counted 19,333, spread across 3,084 genera. Vertebrates run to more than eighteen hundred species, again more than half the national figure, and 243 of China's 335 priority protected animals occur somewhere in the province.

The reason is geography. Yunnan sits where three global biodiversity hotspots meet, and its land rises from tropical lowland to permanent snow within a few hundred kilometres. Species that need heat and species that need cold both find a band of the province that suits them, stacked one above the other.

Some of it is still being counted. New species are described here regularly, and a herd of sixteen Asian elephants that walked five hundred kilometres north from Xishuangbanna in 2021 reminded everyone how little is settled about how these animals use the landscape.

Above Lijiang stands Yulong Snow Mountain, the southernmost snow-capped range in mainland Eurasia, and on its eastern flank sits Baishui Glacier Number One. It is among the most closely monitored temperate glaciers in Asia, and what the monitoring shows is stark.

The glacier has lost around 36 percent of its area since 1951. Its terminus, the point where the ice ends, has climbed from 4,100 metres in 1982 to 4,395 in 2017, retreating up the mountain as the lower ice melts away. Across the whole massif, glacier cover fell by nearly two thirds between 1957 and 2017 while local air temperature rose 0.19 degrees a decade.

A popular story holds that the visitors are to blame, their body heat warming the ice. Researchers tested it and found otherwise: this is climate, working at a speed you can stand on a viewing platform and see the results of. Few places let you look at a warming world quite so directly.