For most of modern history, the world operated on the conviction that if you want to develop your economy, you will damage the environment. The two move in opposite directions, so you can choose one.

This was not the view of ignorant or careless people. It was the lived experience of industrialization.

The British knew that sending children into coal mines during the Industrial Revolution was harmful. But they did it anyway, because they saw no other path to prosperity.

That model spread from Britain to Germany, to the United States, to Japan, to the Republic of Korea, to China, and eventually to every corner of the world that wanted to grow. For nearly two centuries, the trade-off between development and nature was not a debate. It was a fact of life.

That fact has changed only in the past few years, and the agent of change was not idealism. It was price. Twenty years ago, the world took an entire year to add one gigawatt of solar capacity.

Today the same gigawatt is added in half a day. Solar energy costs have fallen by around 90 percent in a decade. Wind costs have followed a similar trajectory. Batteries are now doing the same. When clean energy becomes the cheapest option in most of the world, the old trade-off dissolves.

You no longer have to choose between growing your economy and protecting your environment, because the tools that grow your economy are increasingly the same tools that protect it. The debate that defined two centuries of development has not been won by one side or the other. It has simply been overtaken by technology and economics.

Any nation replacing a drop of oil from the Strait of Hormuz with solar energy saves money, and becomes more energy independent.

This shift changes everything about how we should read what is happening in China.

What looks from the outside like a collection of separate environmental policies is actually something more coherent: a systematic attempt to prove, at scale and over time, that the old trade-off was a historical condition rather than a permanent truth.

I have been watching this unfold for two decades. Earlier this year, I took a boat along the Lijiang River in Guilin, Guangxi Zhuang autonomous region.

That river was once heavily polluted, widely reported as one of China's most polluted rivers. But what I saw from the water settled something for me.

The water is so clean you can go for a swim, maybe even drink it. It shows that protection and prosperity can advance together, and that the decision to treat nature as an asset rather than a sacrifice is one that pays back. Beautiful nature invites tourists and brings prosperity.

The Yellow River, the Yangtze and the Lancang-Mekong rivers sustain hundreds of millions of people across Asia. China is now building a national park at their origin in the Qinghai plateau to protect these watersheds for the long term. On the Talatan grassland nearby, vast solar installations cover what was once barren desert. The panels generate electricity for the national grid while their shade slows the wind, reduces evaporation, and allows grass to grow beneath them.

Herders now graze their sheep underneath what has become the largest solar installation on earth.

Energy production and ecological restoration are not competing here. They are the same project.

This is what makes the concept of ecological civilization genuinely significant. As articulated by Chinese President Xi Jinping, "Lucid waters and lush mountains are invaluable assets." The argument is not that China will sacrifice economic growth to protect nature, but that protecting nature is itself a sound economic strategy. The Yangtze River basin is the proof. A decade ago, a landmark commitment was made in Chongqing to prioritize ecological protection along the river over large-scale development. In 10 years, around 96.5 percent of the river's water meets the high-quality standards. Over the same period, the region's GDP has more than doubled.

The tiger population in the Northeast China Tiger and Leopard National Park has grown from 27 to around 70. Nearly 50,000 people have got jobs connected to China's first five national parks. Managed well, nature generates wealth rather than competes with it.

This March, China adopted the Ecological and Environmental Code, consolidating 30 separate environmental laws into a single statutory framework. It is the second formal code in Chinese law after the Civil Code. It shows that while some other countries are retreating from environmental commitments, China is embedding those commitments in legal foundations.

The message is that this direction will hold, regardless of short-term economic pressures. That kind of institutional continuity is precisely what makes ecological recovery possible. You cannot restore a river or a tiger population in one political cycle. You can only do it by committing over decades and meaning it.

This matters beyond China because the old trade-off weighed most heavily on the countries that could least afford it. The logic of pollute first and clean up later was, in practice, a sentence passed on poor nations, not a strategy chosen by them. Clean up later turned out to mean never, or not until enormous damage had already been done.

But developing countries no longer face that sentence. Clean energy is not a luxury technology available only to wealthy nations.

It is, increasingly, the cheapest technology available to anyone. In Rwanda, protecting mountain gorillas generates around $1,500 per hour-long visitor experience, making conservation one of the country's most important economic assets. The gorillas are worth more alive in their habitat than they could be in any other form.

India, the home of around 75 percent of the world's tigers, has doubled its tiger population, not only for animal welfare but as an economic strategy. That is the logic that China is applying to its rivers, its forests, and its wildlife at a scale the world has not seen before.

The debate whether a country must choose between development and nature shaped two centuries of industrial history. Many still have that old mindset. But the economics of clean energy and the practical experience of ecological restoration have now answered that debate. The choice was never as fixed as it seemed.

And for the nations still at the beginning of their development paths, it is no longer a choice at all.

The author is a diplomat and former minister of international development and minister of environment of Norway. He was also the under-secretary-general of the United Nations and executive director of the United Nations Environment Programme.

The views don't necessarily reflect those of China Daily.

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