Several natural factors that once helped keep temperatures lower are on the downside. For example, cloud cover and aerosols (tiny particles in the air) reflect sunlight back into space, helping cool the Earth. However, changes in air pollution and weather patterns have altered cloud formation and aerosol levels.

Additionally, melting ice and snow reduce the Earth’s reflectivity, or albedo. White ice reflects sunlight, but when it melts, darker land or water absorbs more heat, accelerating warming. This feedback loop makes hot regions hotter and contributes to the rise in extreme temperatures seen in many parts of the world.