GLASGOW, Scotland (AP) — The dramatic drop in carbon dioxide emissions from the pandemic lockdown has pretty much disappeared in a puff of coal-fired smoke, much of it from China, a new scientific study found.

A group of scientists who track heat-trapping gases that cause climate change said the first nine months of this year put emissions a tad under 2019 levels. They estimate that in 2021 the world will have spewed 36.4 billion metric tons of carbon dioxide, compared to 36.7 billion metric tons two years ago.

At the height of the pandemic last year, emissions were down to 34.8 billion metric...