PARIS: Holding long-term global warming to two degrees Celsius — the fallback target of the Paris climate accord — is now “impossible,” according to a stark new analysis published by leading scientists.

Led by renowned climatologist James Hansen, the paper appears in the journal “Environment: Science and Policy for Sustainable Development” and concludes that Earth’s climate is more sensitive to rising greenhouse gas emissions than previously thought.Compounding the crisis, Hansen and colleagues argued, is a recent decline in sunlight-blocking aerosol pollution from the shipping industry, which had been mitigating some of the warming.

An ambitious climate change scenario outlined by the UN’s climate panel, which gives the planet a 50 percent chance of keeping warming under 2C by the year 2100, “is an implausible scenario,” Hansen told a briefing late on Tuesday.

“That scenario is now impossible,” said Hansen, formerly a top Nasa climate scientist who famously announced to the US Congress in 1988 that global warming was underway.