As the world becomes ever more inter-connected, with the US and China lodged as the very keystone of the new global arch, it has become common place for us to think in terms of “food chains,” those infinitely complex but elegant sequence of causes and effects that must be kept in a state of health in the natural world, if the food on which we all depend, is to grow and people are to flourish. One of the most critical elements in the “food chain,” is, of course, water, which depends on its own infinitely complex, and equally elegant, chain of cause and effect. Especially in the great rivers of the world, their waters comes from complex, trans-national hydrological systems that often flow from one country to another and rely on a web of inter-locked environmental factors. And, there is no country in the world that now sits at a more critical hydrological nexus than China. Why? Because almost all the major river systems of Asia rise on the Tibetan Plateau and the high altitude glacial ice systems that lie in these Tibetan regions of China serve as frozen reservoirs for most of Asia. Seen from this perspective, China has become the Central Kingdom in a new way, one which we have only recently begin to understand: It is central to the welfare of people from Pakistan and the Indus River in the West to the North China Plain and the Yellow River in the East. But, while China bears an immense responsibility to protect and share this most precious resource, water, it cannot alone guarantee to maintain the environmental balance in the Greater Himalaya mountains of the Tibetan Plateau upon which so many people now depend.
In an endless cycle of evaporation and condensation, water is in constant motion, falling on the earth to nourish life, and then being taken up again into the atmosphere through evaporation only to be purified and redistributed around the world once again as rain and snow. During this delicately calibrated and never ending process, that is strangely reminiscent the whole Buddhist notion of life, death and reincarnation which is so much a part of the religious life of the Tibetan Plateau , there is really only one link in this miraculous process where water, whose very nature is fluid, becomes reduced to a state of suspended motion. That is when, after it is precipitated to earth in colder alpine climes or during wintertime, it becomes frozen and immobilized in one of the planet’s ice fields or glaciers. The largest ice masses on earth are situated in the Arctic, the Antarctic and in that grand arc of mountains that stretches from Afghanistan and the Hindu Kush, through the Karakorum Range above Pakistan and India, toward the Himalaya Range that rims India, Nepal, Bangladesh and Burma, before lancing northward at the Hengduan and Daxueshan ranges to form the eastern most tier of the vast Tibetan Plateau. Because this high altitude frozen reservoir sequesters the largest ice mass between the North and South Poles, it has come to be known as the “Third Pole.” But, unlike the Arctic and the Antarctic, whose melt waters flow into the oceans, the melt waters of the Third Pole feed the great river systems of Asia. It is around these rivers that the great civilizations of the region have arisen, and on whose flows some two billion people continue to rely today.
The tens of thousands of glaciers in these mountains collect snow fall in their high-altitude “accumulation zones,” which as this snow fall compresses into ice, pushes the glacier slowly down hill until it reaches its “abalation zone” where it begins to melt during the warm summer months, or “shoulder season.” It is just at this time, when rains from the seasonal monsoons that arrive annually in the area have ceased and that ice starts to melt rapidly, that the frozen water tower begins to release critical supplemental flows that feed the Amu Darya, Indus, Tarim, Ganges, Brahmaputra, Irawaddy, Salween, Mekong, Yangtze and Yellow rivers.
These vast fields of ice and glaciers, or “cryospheres,” have been nature’s way of setting aside a reserve account of this precious resource and then rationing it out at critical times in a way that kept these life-sustaining rivers flowing at sufficient levels to support the civilizations, people, agriculture and industry downstream which have grown dependent on them over the millennia.
The ability of a glacier to keep accumulating ice at a rate equal to, or greater than, its melt rate is known by glaciologist as “mass balance.” And, over many tens of thousands of years, even as there have been temporary fluctuations in the climate caused by orbital wobbles of the earth, sunspots, volcanic eruption and the like, these glaciers have maintained their balance, without precipitous change.
Now, however, another great chain of cause and effect, “anthropomorphic climate change” (changes in the global climate patterns induced by man-made causes such as the burning of fossil fuels and the release of green house gases into the atmosphere) has begun to intersect with the water cycle. Global warming has not only begun to trigger perturbations in historic rainfall patterns in many parts of the globe – causing floods, droughts, hurricanes, typhoons, blizzards and ice storms and other kinds of aberrant weather patterns – but has also led to elevated temperatures and the increasingly rapid melting of the planet’s ice fields. Indeed, in such mountain ranges as the Himalayas, temperature elevations have been rising at more than double global averages, because of the way in which latent heat from moisture rich air from lower and more tropical climes is finally released at higher altitudes in the process of this air cooling, condensing and then falling as rain or snow.
Of course, as global warming proceeds, in the short-run flows in Asia’s major rivers systems will increase. And , as populations increase and urbanization continues with the growth of cities, increased numbers of downstream users will become dependent on this added increment of flow.
However, in the long-run, as global warming causes the capital account of this critical frozen resource to become depleted, releases will not only be deranged, but will diminish. Since many of these river courses are trans-national and are now relied on by hundreds of millions of users, and since there is as of yet no adequate body of international law governing riparian claims on such river systems, it is not unlikely that major struggles will erupt over decreasing flow volumes.
For example, the Mekong River rises on the southeastern tier of the Tibetan Plateau inside China as the Lancang River, but then flows down through Southeast Asia as the lifeline for four other countries, Thailand, Laos, Cambodia and Vietnam. The Irawaddy River rises in the same region of China as the Nujiang and then flows down into Burma where it becomes the most important waterway in this fertile, if presently misbegotten, land. And the Indus, rises in Western Tibet, but then flows west through Indian-controlled Kashmir before finally crossing the armed frontier into Pakistan in the shadow of the Karakorum Range to become the key water source for much of that already embattled land. Indeed, partially because of increased flows from glacial melt due to climate change, a year ago Pakistan experienced its worssflood in recoreded history
So, for much of Asia, the water cycle and the carbon cycle intersect at the nexus of glaciers and rivers. Their interaction presents the world with a complex and potent cocktail of environmental, resource and national security problems for which we do not yet have, nor are we likely soon to have, any remedy.
The best solution to these looming trans-national water resource problems is a pre-emptive one: to keep the cryosphere of this once remote and seemingly disconnected arc of mountains in its current frozen state. For, once these glaciers waste away and seasonal flows diminish, states will inevitably begin to argue, compete, contend and even fight for their shares of vital river water that their people need to survive. By then, however, it will be too late to act.
While most of the Tibetan Plateau lies within China’s sovereign boundaries, Beijing’s ability to protect these fragile ice systems alone, is limited. It is true that China is now the world’s largest user of coal and emitter of green house gases. Indeed, the US and China together emit some 40% of all green house gasses (in roughly equal amounts), although historically the US has emitted almost 30% of all energy related CO2 emissions, while China has produced less than 10%. What is more, the average American still emits approximately four times as much CO2 per capita as the average Chinese. This question of equity is one of the thorniest dividing the two countries as they seek ways to confront this challenge together.
Whatever the balance sheet, one thing is certain: There will be no remedy to climate change, and the melting of the glaciers on the Tibetan Plateau, unless the US and China quickly find new ways to work together. This is a challenge of daunting proportions, with a still very uncertain conclusion. But, it is the most important long-range challenge the two countries face.
Orville Schell is the Arthur Ross Director of the Asia Society’s Center on U.S.-China Relations