That's because the sulfur dioxide, a pollutant which forms when sulfur-containing fuel such as coal or petroleum oil is burned, reacts with water vapor to produce aerosols that reflect sunlight back into space. The aerosols have a direct cooling effect, though climate scientists note that their contribution to global cooling or warming when they are reduced remains a complex area of research. Extreme temperatures are fueled by the climate crisis, the chief driver of which is the burning of fossil fuels. All of the climate models will give you slightly different answers because of the way that they do their emissions of sulfur dioxide," Haywood said. "So, we are uncertain about how much impact the IMO regulations will have had on global mean temperatures."

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Persons: Yuan, Laura Wilcox, everyone's, Jim Haywood, Haywood, You've, Jim Hansen Organizations: United Nations, International Maritime Organization, Ucg, Getty, Communications, University of Maryland, National Centre for Atmospheric Science, University of Reading, El Nino, University of Exeter, CNBC, El, NASA Locations: London, Europe, Tonga