COMMENTARY: China's Planned Megacity Clusters Bump Up Against Climate Change
An area of 400 million people, including Beijing, is forecast to get so hot by the end of century that it will be rendered almost uninhabitable.
The Chinese government wants to create 19 megacity clusters, to be connected by a burgeoning high-speed rail system and other transportation and communication links. Some would have more than 100 million people.
By any accounting, the urbanization of China is a modern-day marvel – far and away the biggest migration of people in history. The population of China's cities has quintupled over the past four decades, reaching 813 million. It has been key to improving living standards and boosting incomes across the sprawling Middle Kingdom.
It's natural for the government to follow up by building these planned urban clusters. But there is a problem with several of them, including one centering on Beijing, that no one seems to be addressing: climate change.
An MIT study published July 31 by the science journal Nature Communications projects that by the end of the century, heat and humidity are going to be so severe on the North China Plain (NCP) that it will be impossible for farmers to do their work.
It says the area, when considering humidity caused by massive irrigation, will suffer more from climate change than any other spot on Earth and will barely be livable.
"Under the business-as-usual scenario of greenhouse gas emissions, North China Plain is likely to experience deadly heat waves with wet-bulb temperature exceeding the threshold defining what Chinese farmers may tolerate while working outdoors," it says. "China is currently the largest contributor to the emissions of greenhouse gases, with potentially serious implications to its own population: Continuation of the current pattern of global emissions may limit habitability in the most populous region of the most populous country on Earth."
Professor Elfatih Eltahir at MIT, one of the study's authors, told the British newspaper The Independent, "This spot is going to be the hottest for deadly heat waves in the future, especially under climate change."
Understanding the Corridors
The NCP encompasses the Beijing-Tianjin corridor, most of Shandong, Hebei, and Henan provinces, and parts of Jiangsu and Shanxi provinces. Although this area is slightly smaller than California, 400 million people live there.
The Beijing-Tianjin corridor is one of the three main city clusters envisioned by Chinese leaders, and it sits in the heart of the NCP. Three smaller planned city clusters also fully or partly occupy the plain. They are dubbed the Central Plains (centered on Zhengzhou); Taiyuan, and Shandong Byland.
As governments everywhere grapple with the increasingly dire effects of climate change, China seems to have a special problem. The NCP serves as a key agricultural belt along the Yellow River and its tributaries. It's considered the heartland of China.
In recent decades, its irrigation systems have been vastly expanded to meet the growing food needs of China's huge population The MIT study noted that such irrigation "impacts significantly the surface radiation, surface energy balance, and boundary layer development in ways that impact surface humidity and temperature."
In other words, crop-watering systems lacing through the area increase the humidity, resulting in nearly intolerable heat indexes, that is, what humans feel the temperature is. The study notes some of the more recent heat waves to hit China reveal that temperatures in the NCP are rising at a rate nearly double the global average.
What this means for China's urban planners is hard to fathom. Some of the world's largest metropolises already occupy this region. Beijing alone is a city of 21 million people. Obviously, it's not feasible to simply vacate the land and move hundreds of millions of people elsewhere.
But officials should at least contemplate whether they want to exacerbate what could become a slow-rolling catastrophe by building massive new infrastructure in such a place.
Plan Now for the Future
It's becoming more apparent year by year that climate change is exacting big tolls that include record forest fires, massive hurricanes, and deadly heat waves with unprecedented temperatures around the world. Scientists know they will only worsen.
Mitigating steps are being planned in coastal cities around the world, such as building seawalls as the oceans rise. While China is taking laudable actions to produce more energy from renewables and move slowly away from coal, its central planners now must consider how to proceed in the North China Plain.
"National climate change policy in China will need to carefully evaluate and weigh the projected negative impacts of severe heat waves on local population against the positive impacts of economic development," the MIT researchers conclude. "Enhanced investments in renewables, already adopted widely in China, may offer an alternative pathway that achieves economic development and mitigates local impacts of future global climate change.
"However, even under moderate mitigation scenarios, severe heat waves are projected for NCP which may necessitate simultaneous development of effective public health adaptation measures to avoid the deadly impacts of future heat waves."