Sustainability

Did Cutting Ship Emissions Worsen Climate Change?

Have we inadvertently worsened climate change by reducing pollution from large ocean-going ships? A new paper from a team of NASA scientists has reignited one of the most contentious debates in climate science.

Published in the journal Nature, the research suggests that a significant decrease in sulfur dioxide emissions in 2020, following the implementation of new international shipping fuel regulations, has led to a "termination shock." This could potentially increase the world's ocean temperatures by 0.16 degrees Celsius (0.29 degrees Fahrenheit) over seven years, thus accelerating global warming significantly.

The scientists explain that sulfur dioxide, emitted from burning high-sulfur fuels in ships, reacts with water vapor in the atmosphere to form aerosols that reflect sunlight back into space. These aerosols also enhance cloud cover, providing a cooling effect on the oceans. By reducing sulfur dioxide emissions, they argue, more solar energy has been reaching the ocean surface. The authors also propose that their findings highlight the potential of geoengineering technologies, such as cloud brightening, which some researchers believe could be used to mitigate global warming.