THE PARIS AGREEMENT on climate change is a triumph of diplomacy. At its best, diplomacy enables countries to find the common good, just as politics at its best enables a single society to find the common good. The success of the new agreement will depend on whether diplomacy and politics can defend the common good against the ever-present tendencies toward corruption, confusion, and conflict.
At the core of the climate crisis is a challenge of collective action. Every nation emits carbon dioxide and other greenhouse gases that dangerously warm the planet. Yet decarbonization is costly, at least in the short term. Each country therefore tries to push the other countries to take on a disproportionate share of the burden. The resulting decarbonization is too little, too late for planetary safety.
The key, of course, is to agree to move together. If all countries were in a symmetrical situation, common global action would probably be straightforward. Yet the situation is not symmetrical. Some countries are rich, others poor. Some countries have added massively to greenhouse gas concentrations in the past; others have added little. Some countries, such as small island states and desert countries, are extremely vulnerable; others are less so, at least relatively.
The result has been more than two decades of wrangling, until Paris. Back in 1992, in the UN Framework Convention on Climate Change (UNFCCC), the rich countries (listed in a famous Annex I) agreed to take the lead on stabilizing greenhouse gases. Then, in 1997, the US Senate balked, rejecting the very terms it had ratified back in 1992. The Hagel-Byrd Resolution declared that the United States should not act unless the developing countries acted symmetrically.
The result was 18 years of standoff. The US Senate repeatedly insisted that China should act alongside the United States. China, on the other hand, pointed to the original treaty to say that the United States is obliged to move first, since China is a "non-Annex-I country," and much poorer than the United States. What China viewed as basic fairness, and as part of the original treaty, the US Senate increasingly viewed as a threat to US interests in the face of rising competition from China.
This gridlock was finally broken in Paris, for three reasons. The first is that China's economy has grown so much, and is so dependent on coal, that China has become the world's largest greenhouse gas emitter, with roughly twice the carbon emissions of the US, though only half as much per person (given that China's population is roughly four times that of the United States). China recognized that it could no longer plausibly demand action by others without acting itself.
The second is that China is literally choking on its own fumes, with an urban air cover that is poisoned by coal, automobile exhausts, and other industrial-and-household-based emissions. China's own public health and social stability are threatened by air pollution. Moreover, with a semi-arid northern region and an arid western region, China is incredibly vulnerable to long-term climate change.
The third reason was diplomacy, skillfully undertaken by President Barack Obama and Secretary of State John Kerry with President Xi Jinping and his leadership team. Quiet US-China diplomacy over several years enabled Obama and Xi to walk through the doors of the Paris negotiations together, telling the world that the two largest emitting countries, China and the United States, would cooperate together if the other 194 signatories of the UNFCCC would join in common action.
Here the world's finest diplomats went to work. US Secretary-General Ban Ki-moon and France's Foreign Minister Laurent Fabius, the president of the climate conference, patiently and brilliantly worked with the more than 190 delegations to forge a balanced package of obligations and commitments that convinced every country that the others were also acting fairly according to what is famously called "common but differentiated responsibilities."
The rich countries promised more financing for the poor countries; the rich countries, and the private sector, promised to step up research and development on low-carbon energy and to make the resulting technologies available to the poorer nations. The rich countries promised to help build technical capacities. The poor countries were given more time and flexibility in tackling their emissions. And so forth.
Diplomacy is the art of finding the common good, but cannot by itself be the art of implementation. Success against climate change will now depend on practical policies implemented over several decades, including regulations to ban coal-fired power plants; technological advances; a sound business environment (such as scrapping subsidies for fossil fuels); city-level plans of action including infrastructure for smart grids and electric vehicles; financial markets that divest from coal and shift to wind and solar power; and the design and implementation of long-term pathways for deep decarbonization. With the Paris agreement, we are only at the start, not the finish line, of implementing climate safety.
One major question is whether the Republican-led Congress will now drop its opposition to climate action given that China is on board. The American voters want action. The United States has the opportunity for a high-tech, low-cost transition to a low-carbon economy, though much of Congress seems to be unaware of this key point. Of course, much of the long-standing congressional opposition is not really about China or the lack of technology knowledge on Capitol Hill, but about political corruption, namely the campaign contributions of Big Oil.
At the end of the day, the most important determinant of success or failure worldwide will indeed not be technical, but moral.
The Paris agreement, as well as the Iran nuclear deal and the recent adoption of the Sustainable Development Goals, give us hope for global-scale cooperation and problem-solving. Yet every day some politicians also urge the worst from us: to increase bombings and war, to hate "the other," to accelerate the arms race (notably these days with China), and to act as if the rest of the world is the enemy, not the partner in problem solving.
We will succeed in implementing the Paris agreement, and indeed in keeping global peace, if we remember and heed JFK's great call to cooperation: "For, in the final analysis, our most basic common link is that we all inhabit this small planet. We all breathe the same air. We all cherish our children's future. And we are all mortal."
Jeffrey D. Sachs is director of the Earth Institute at Columbia University and author of "The Age of Sustainable Development.''