What's the difference between good ozone and bad ozone?

Good ozone is found in the Earth's upper atmosphere and protects us from harmful solar radiation, while bad ozone is ground-level ozone that contributes to air pollution.

Good ozone, also known as stratospheric ozone, is located in the Earth's upper atmosphere, specifically in the stratosphere, which is about 10 to 50 kilometres above the Earth's surface. This layer of ozone is crucial for life on Earth as it absorbs the majority of the Sun's harmful ultraviolet (UV) radiation. Without this protective layer, we would be exposed to high levels of UV radiation, which can cause skin cancer and cataracts, harm ecosystems, and damage sensitive crops.

On the other hand, bad ozone, or tropospheric ozone, is found at ground level and is a harmful air pollutant. It is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. Emissions from industrial facilities, electric utilities, motor vehicle exhaust, petrol vapours, and chemical solvents are some of the major sources of NOx and VOCs.

Bad ozone is a primary ingredient in urban smog and can have various health effects. It can cause respiratory problems, trigger asthma, reduce lung function and cause lung diseases. In addition to its harmful effects on health, bad ozone can also have detrimental effects on the environment. It can lead to reduced agricultural and commercial forest yields, reduced growth and survivability of tree seedlings, and increased susceptibility to diseases, pests and other stresses such as harsh weather.

In summary, while good ozone in the stratosphere plays a protective role by shielding us from the Sun's harmful UV radiation, bad ozone at ground level is a harmful pollutant that poses health and environmental risks. It's important to note that human activities play a significant role in the creation of bad ozone, and therefore, we have a responsibility to take measures to reduce its levels.