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%–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.