Multiple choice

Global dimming, observed for several decades after 1950s, is thought to have been caused by

  1. Methane

  2. Particulate matter

  3. CFCs

  4. Carbon dioxide

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. Global dimming is thought to have been caused by an increase in particulates such as sulfate aerosols in the atmosphere due to human action.