A team of scientists has estimated the amount of carbon emissions from Canada's 2023 wildfires was far above the annual total emitted by the country through the use of fossil fuels in 2022.

Smoke from the blazes that burned 150,000 square kilometers caused serious air pollution, wafting across the border into eastern parts of the United States such as New York.

The international team disclosed its research in the scientific journal, Nature. It analyzed satellite and other data, and estimated that the wildfires emitted roughly 647 million tons of carbon between May and September last year.

The team says the amount was more than four times larger than Canada's annual fossil fuel emissions in the previous year.

It also says the volume was comparable to India's annual emissions in 2022, a year in which the country was the third-biggest emitter globally.

The team ascribes the fires to widespread hot and dry weather, and what it calls "extreme" temperatures relative to the historical record. It says "climate projections indicate that these temperatures are likely to be typical during the 2050s."

The team warns, "Such conditions are likely to drive increased fire activity and suppress carbon uptake by Canadian forests."