Clean-air policies implemented globally are leading to a sharp decline in sulphur emissions, which scientists increasingly believe is slightly speeding up global warming. Sulphur pollution, formed by tiny particles in the air, reflects sunlight back into space, partially counteracting the warming effect of carbon dioxide.
While carbon dioxide emissions remain near record highs, the loss of this cooling effect is contributing to an accelerated rate of warming. Reto Knutti, a professor of climate physics at ETH Zurich, stated that "it's pretty clear that the rate of warming has accelerated," after his team attempted to remove the effects of natural fluctuations like El Niño.
The past three years have been the warmest ever recorded. The Met Office forecasts that 2027 is "very likely" to surpass 2024 as the warmest year on record. Prof Piers Forster, a climate scientist at the University of Leeds, estimates that declining aerosol pollution may now be adding approximately 0.05C to 0.1C of warming per decade.