Wang Tianyi from the China Meteorological Administration discusses the impact of Tonga's volcanic eruption on the climate and air. Expert says the volcanic eruption is likely the largest in 30 years and may cause temporary global cooling. The eruption sent a huge could of ash and sulfur dioxide high into the upper atmosphere, where the gas combines with water to create aerosol particles that help scatter some of the sun's rays, keeping them from hitting Earth's surface.