What are Sulfate Aerosols? How do They Impact the Environment.

Sulfate aerosols have a bad reputation because they are thought to diminish the ozone layer. All consumer aerosols sold in the US use propellants such as hydrocarbons and compressed gasses like nitrous oxide. These do not deplete the ozone layer. It turns out that most aerosols are cooling and play an important role in Earth's climate. Most aerosols are brighter than the land or the oceans, and cool the Earth by reflecting sunlight back to space. Darker aerosols can absorb significant amounts of light. Pure sulfates and nitrates reflect nearly all radiation they encounter, cooling the atmosphere. Aerosols come from volcanoes, dust storms, fires, vegetation, sea spray, burning of fossil fuels and land use. Warming aerosols include black carbon and dark soot. Cooling aerosols include dust, sulfate particles and sea spray. Aerosols can affect the climate in two ways, through direct or indirect processes. Depending on the assumptions about the properties of the resulting sulfate particles in the stratosphere, climate model simulations produce global average cooling of 3–15 °C, lasting for a decade or more.