When China makes a climate pledge, the world should listen

A few years ago, one of us (Myles Allen) asked a Chinese delegate at a climate conference why Beijing had gone for "carbon neutrality" for its 2060 target rather than "climate neutrality" or "net zero", both of which were more fashionable terms at the time.

Her response: "Because we know what it means."

It was a revealing answer: China, unlike many other countries, tends not to make climate commitments that it doesn't understand or intend to keep. And that's why its latest pledge — cutting greenhouse gas emissions by 7% to 10% by 2035, as part of its commitments under the Paris agreement — matters more than the underwhelmed response might suggest.

To be fair on those other countries, lofty goals have played a role in driving the climate conversation about what is possible: there is always the argument that it is better to aim for the moon and miss than aim for the gutter and hit it.

But the climate crisis needs more than aspirations. It needs concrete, plausible plans.

That's what makes China's pledge so significant: Beijing has form in only promising what it plans to deliver. Having promised to peak emissions this decade, barely 50 years after it began to industrialize in earnest, it looks set to achieve that. And in the process, become a world leader in wind power, solar energy and electric vehicles.

Meanwhile, in the scientific literature…

A paper appeared in the journal Nature Communications at the end of August that provides some context for China's announcement and ought to have received much more attention.

In it, climate scientists Junting Zhong and co-authors describe what they call a "reality-aligned scenario". This means a pathway for emissions over the coming century that is consistent with emissions to date and countries' near-term commitments.

The paper is provocatively titled "Plausible global emissions scenario for 2°C aligned with China's net-zero pathway" (provocative because of the implication that some other scenarios out there are, well, less plausible).

In their scenario, global carbon dioxide emissions peak this decade and reach net zero around 2070, accompanied by immediate, sustained but not particularly dramatic reductions in emissions of methane and other greenhouse gases. In response, global warming is expected to peak at just over 2°C towards the end of this century before declining below 2°C early in the next.

Crucially, Zhong and his colleagues break out China's contribution. In their scenario, the country's carbon dioxide emissions would peak in the next few years before a steady decline brings them close to zero by 2060. Methane emissions would begin to decline immediately.

There is much to discuss in the relationship between this scenario and China's latest emission pledge. How much of that 7% to 10% reduction in all greenhouse gases by 2035 will be delivered by (very welcome) cuts in methane emissions? Breaking out separate contributions of long-lived (CO₂) and short-lived (like methane) greenhouse gases would be helpful to understand the implications of China's pledges for global temperature.

Zhong and colleagues see land use changes (such as reforestation) playing only a minimal role in China's long-term climate plan. So why does Beijing's new pledge put so much emphasis on planting trees? Is this just a stopgap, or the start of a bigger reliance on land-based carbon dioxide removal?

And while renewables are central to China's strategy, the country will also need to store captured carbon (from power plants or factories) on a massive scale. The real question may be around how China is going to deliver all this.

That's why the phrase "while striving to do better" in President Xi's announcement is so important. The world has a keen interest in China over-delivering.

Why the silence?

But perhaps the most remarkable aspect of all this is how little discussion there has been of the work by Zhong and his colleagues. It was clearly relevant: it came out just as China was preparing its pledge, it was published in one of the world's top scientific journals, and one co-author has a prominent role in the IPCC. Yet despite all that, it received almost no online attention.

Perhaps most climate commentators were too preoccupied with responding to a very different document: a "critical review" commissioned by the US Department of Energy of greenhouse gas impacts on the U.S. climate.

Whether or not you agreed with their conclusions, Zhong and his team's paper was rigorous, transparent and peer-reviewed. The U.S. review was none of those things, and already widely criticized as flawed. Yet it dominated headlines and commentary for weeks.

While the world's second-largest emitter was debating a dodgy dossier, a carefully presented and comprehensive scenario, directly relevant to the climate policies of the world's largest emitter, passed largely unnoticed.

That's a missed opportunity. China's targets aren't just slogans or aspirations — they are statements of intent, grounded in what the country believes it can deliver. And where China goes, others will follow. Paying attention to analyses like the one from Zhong and his colleagues help us understand both China's role and the world's chances of keeping warming below 2°C.

That's why President Xi's call to "do better" applies not just to countries, but to scientists, commentators and climate policy-watchers too. Don't be distracted by the usual suspects flooding the zone.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.