Bruno Rodriguez is only 18, but he has seen enough in his time on Earth to know that he must to do something for the planet. Inspired by the student climate strikes in Europe, he founded Youth for Climate Argentina in his home country. The group drew more than 8,000 demonstrators to the national congress in May, and its leaders worked with senators to pass a resolution on 17 July, declaring a climate emergency.

Argentina is responsible for less than 1% of annual global emissions, but Rodriguez says the science is clear: everyone must take aggressive action if the world is to avoid a massive environmental and humanitarian crisis. “There is no middle ground,” says Rodriguez. “We need radical industrial transformation.”

Rodriguez is part of a grass-roots climate movement that is gaining momentum across the globe. It is driven in part by a new generation of young activists, and by mounting evidence that global warming is accelerating, which is increasing the odds of severe heatwaves in Europe, deadly fires in the western United States and massive tropical storms fuelled by increasingly warm oceans, among other things. With greenhouse-gas emissions still rising, frustrated activists are taking to the streets to pressure politicians to keep their promises.

This new activism will be on full display as groups in 150 countries stage strikes around next week’s global climate summit in New York City, convened by United Nations secretary-general António Guterres. The meeting comes nearly four years after the Paris climate agreement, which seeks to limit global temperatures to 1.5–2 °C above pre-industrial levels. Guterres’s goal is to build momentum as countries prepare to submit new commitments next year.

Whatever they decide, nations will have to reckon with some difficult numbers that will ultimately determine whether the world can avoid the rapidly approaching climate meltdown. Nature documents the scale of the challenge in an infographic that explores energy use, carbon dioxide pollution and issues of climate justice. At a time when countries have pledged to curb greenhouse gases sharply, the data show that annual emissions spiked by 2.1% in 2018 — owing in part to increased demand for coal in places such as China and India.