Hydrogen itself does not have a direct role in ozone layer preservation, but it can contribute to its protection by providing an alternative and clean source of energy when used as a fuel instead of relying on fossil fuels, oil, or natural gas. This is because hydrogen does not emit compounds that deplete the ozone layer or greenhouse gases. This means that using hydrogen in applications such as transportation, power generation, and industry can help reduce emissions harmful to the environment, including those that damage the ozone layer.
Figure 1″Representation of the ozone layer over Antarctica as it existed on November 8, 2022. Image: NASA.”
International Day for the Preservation of the Ozone Layer is celebrated on September 16th every year, commemorating its importance for life on Earth. The ozone layer, located at an altitude of 10 to 50 kilometers above the Earth’s surface, plays a crucial role in protecting life against ultraviolet (UV) radiation from the sun.
In the 1970s, it was discovered that human activity was damaging this layer, leading governments to establish agreements to regulate ozone-depleting gases:
The Vienna Convention for the Protection of the Ozone Layer, adopted in 1985 and in force since 1988, established a global commitment to research and control human activities affecting the ozone layer. However, it did not impose specific actions on harmful substances.
The Montreal Protocol, arising from this Convention in 1987, regulated about 100 artificial chemical substances known as ozone-depleting substances (ODS) that harmed the ozone layer and contributed to climate change. It is the only UN treaty ratified by all of its 198 Member States and is considered one of the most successful international environmental agreements; its main objective is to gradually eliminate the production and consumption of substances that deplete the ozone layer, such as chlorofluorocarbons (CFCs) and other halogenated compounds.
Over the years, the Montreal Protocol has been amended and strengthened several times to address new substances and challenges. Thanks to this protocol and international efforts, a significant reduction in the emission of harmful substances for the ozone layer has been achieved, and it is expected that the ozone layer will gradually recover to pre-1980 levels by mid-century.
The Kigali Amendment, in effect since 2019, addresses hydrofluorocarbons (HFCs), replacements for ODS that are potent greenhouse gases. Their gradual phase-out is projected to prevent up to 0.4 degrees Celsius of global temperature increase by the year 2100, preserving the ozone layer in the process.
In this context, a little-known but crucial relationship arises: the interaction between hydrogen and the ozone layer. Hydrogen, the most abundant element in the universe, can play a significant role in the preservation and recovery of our planet’s protective layer.
Hydrogen and Ozone: A Subtle Relationship
The relationship between hydrogen and the ozone layer lies in its ability to influence the amount of water present in the stratosphere, where the ozone layer resides. When hydrogen is released into the atmosphere, it can ascend to the stratosphere, where it can interact with water molecules.
Hydrogen is capable of binding with water molecules in the stratosphere, forming what is known as hydroxyl (OH), which is a chemical functional group consisting of one oxygen atom and one hydrogen atom covalently bonded. Meanwhile, the ozone layer is primarily composed of oxygen molecules (O3) and is located in the stratosphere of Earth’s atmosphere.
Figure 2 Simplified annual tropospheric ozone (O3) budget.
The preservation of the ozone layer is directly related to the reduction of chemical substances known as chlorofluorocarbons (CFCs) and halons. These compounds release chlorine and bromine atoms into the stratosphere, which are highly destructive to ozone molecules when they break down.
Hydroxyl plays an important role in the atmosphere, particularly in the chemistry affecting pollutants and greenhouse gases, as it is known as the “atmospheric detergent” because it reacts with a wide variety of chemical compounds, including many pollutants, breaking them down into simpler compounds, thus allowing for natural regeneration. This subtle but essential interaction between hydrogen and the ozone layer may be a crucial step on the path towards its recovery and long-term health.
The Vital Impact of Green Hydrogen on Ozone Layer Preservation
In recent times, a debate has emerged surrounding the role of hydrogen in the transition towards a more sustainable economy. Specifically, misinformation has attempted to obscure the positive impact of hydrogen, focusing on what is referred to as ‘grey hydrogen‘. It is crucial to clarify that this type of hydrogen does not represent the entire spectrum of production methodologies.
Gray Hydrogen vs. Green Hydrogen: Understanding Their Environmental Implications
Grey hydrogen is produced from natural gas through a process known as methane reforming. This process involves the release of carbon dioxide (CO2) as a byproduct, which raises significant concern, as CO2 is considered to be one of the major greenhouse gases responsible for climate change.
In addition to CO2, the grey hydrogen production process can release atmospheric pollutants such as nitrogen oxides (NOx) and fine particles, which have adverse effects on overall air quality.
While this type of hydrogen is economically cheaper to produce, it is far from being an ideal or environmentally friendly solution.
In contrast, green hydrogen is produced through the electrolysis of water using renewable energy sources widely available such as solar or wind power. This process releases oxygen and captures carbon, providing a clean and sustainable energy source. By using renewable energy sources for its production, green hydrogen does not emit CO2 or other harmful greenhouse gases.
The production of green hydrogen is virtually free of CO2 emissions. The only exception may be if the electricity used in the electrolysis comes from non-renewable sources.
Unlike grey hydrogen, the use of green hydrogen helps to prevent the release of compounds harmful to the ozone layer, thus contributing to its recovery and longevity. Additionally, it plays a crucial role in safeguarding the atmosphere and preventing associated damages that happen from excessive exposure to UV radiation. This makes it an essential component in the fight against climate change.
Driving the Transition towards a Hydrogen Economy
While the discussion surrounding hydrogen has largely focused on its ability to mitigate climate change, it is important to highlight how its adoption can also contribute to the preservation and longevity of the ozone layer.
To achieve this, it is imperative to invest in technologies that promote the production, storage, and utilization of hydrogen as an energy source. This includes the development of infrastructure for renewable hydrogen production, as well as the implementation of policies that encourage its adoption in key sectors such as transportation and industry.
World Ozone Layer Preservation Day provides us with a valuable opportunity to reflect on the interaction of elements in our ecosystem and how we can utilize resources like hydrogen to protect and preserve our environment. In doing so, we not only defend our ozone layer, but also pave the way for a cleaner and more sustainable future for generations to come.
By: Catherine Lafaurie/Fuel cells Works
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