Scientists Warn Earth Warming Faster Than Expected — Due to Reduction in Ship Pollution

Leading climate scientist James Hansen says ‘global warming will accelerate’

The past five months have shattered global temperature records, taking scientists by surprise. Many are asking why.

A new study published in Oxford Open Climate Change, led by renowned U.S. climate scientist James Hansen, suggests one of the main drivers has been an unintentional global geoengineering experiment: the reduction of ship tracks.

As commercial ships move across the ocean, they emit exhaust that includes sulfur. This can contribute to the formation of marine clouds through aerosols — also known as ship tracks — which radiate heat back out into space.

However, in 2020, as part of an effort to curb the harmful aerosol pollution released by these ships, the International Maritime Organization (IMO) imposed strict regulations on shipping, reducing sulfur content in fuel from 3.5 per cent to 0.5 per cent.

The reduction in marine clouds has allowed more heat to be absorbed into the oceans, accelerating an energy imbalance, where more heat is being trapped than being released.

In a call with reporters on Thursday, Hansen said Earth’s energy imbalance is much higher than a decade ago.