• Ozone

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Ozone is an inorganic molecule also known as oxygen 3, trioxygen or O3. It derives its name from the Greek verb ozein, meaning “to smell,” due to its specific odor. Its positive or negative effects depend on where it is found. In its highest concentration, in the earth’s stratosphere, it forms the ozone layer, which filters UV radiation and absorbs a large part of the wavelengths harmful to humans, animals and plants. All UV-C, most UV-B and some UV-A radiation is filtered by stratospheric ozone. In lower levels of the atmosphere, it is created by a chemical reaction of pollutants with sunlight and can damage the human respiratory, cardiovascular and central nervous systems, as well as inhibiting photosynthesis in plants. It also acts as a greenhouse gas (GHG) in the troposphere. The different aspects of ozone’s function in the ecosystem are often referred to as “good ozone” and “bad ozone” in public discourse.

The ozone layer – a success story of global environmental regulation

In the 1970s, the scientific consensus that “good” ozone, which is produced naturally in the stratosphere and protects our planet, is affected by ozone-depleting substances, led to widespread political action. The ozone hole was generally accepted and understood to be a threat, especially to human health, due to the proven link to increased skin cancer risk. In 1987, more than 180 nations adopted the Montreal Protocol to phase out the production and use of these substances, which were widely used in coolants, aerosol and other applications. In 2016, the Kigali Amendment was added to further limit the production and use of hydrofluorocarbons (HFCs), which are currently used to replace hydrochlorofluorocarbons (HCFCs) and chlorofluorocarbons (CFCs). Although these do not affect stratospheric ozone, they are GHGs that accelerate global warming.

Unlike global warming, which has prompted protracted negotiations, but as yet few consistent and comprehensive global countermeasures, the fight against the ozone hole was an environmental success story. It showed that the international community can rally around a cause swiftly and efficiently when the science behind an environmental challenge is clearly communicated and both the man-made cause and the solutions are straightforward. More importantly, the results are already observable, as recent research indicates that the ozone layer is healing and should be back to its pre-1980 state by 2060.

How climate change affects ground-level ozone pollution

“Bad” ground level ozone is created by the chemical reaction of air pollutants from fossil fuel emission with sunlight in the troposphere. It affects air quality, can damage plants and is harmful to human health in higher concentrations. The most common health effects are different types of lung disease. Ozone levels are usually highest on warm, cloudless days in or near cities with particularly high pollution levels. Studies indicate that global warming will also increase ground level ozone.

12
%
decrease in chlorine* entering the stratosphere (1993 - 2016)
15
%
decrease in bromine* entering the stratosphere
0.2
°C
to 0.4 °C projected global average warming reduction by 2100 due to Kigali Amendment

* from long-lived ozone-depleting substances controlled under the Montreal Protocol

The Montreal Protocol is one of the most successful multilateral agreements in history for a reason [...] The careful mix of authoritative science and collaborative action has defined the Protocol for more than 30 years and was set to heal our ozone layer.

Erik Solheim, head of UN Environment


Fighting “bad” ozone on the earth’s oceans

NOx, the collective term for the two oxides of nitrogen, reacts with oxygen atoms in combustion engines and forms ground-level ozone in fossil fuel emissions. One of the sectors with the largest potential for a reduction of nitrogen oxide pollution is the shipping industry. MAN Energy Solutions offer proven exhaust gas after-treatment systems that meet the International Maritime Organization’s strict regulations for nitrogen oxide and sulfur pollution, even in Emission Control Areas.

Learn more about emission control of the maritime industry

Decarbonization of shipping on the horizon

Sustainability goals at MAN Energy Solutions’ two-stroke engine business run parallel with ambitious targets set by the IMO for the whole shipping industry. MAN is developing new technologies and innovative solutions in full support of these targets to ensure a cleaner future for transportation at sea.

Learn more about how marine shipping can help to achieve global climate goals