Can lasers put an end to Climate Change?
Moonshot Challenge ’23 | Most Impactful Award Winner
Picture this: you wake up early in the morning, and as you step outside, you take a deep breath of fresh, crisp air. It fills your lungs and invigorates you for the day ahead. You look around, and the sun is shining, and you feel a sense of peace. This is the world without air pollution and climate change, a world of possibility that we can create with our collective efforts.
As you go about your day, you notice the health and vibrancy of the environment. The trees and greenery are thriving, and the birds and wildlife are flourishing. You no longer see smog or haze. The skies are a clear blue. You feel a sense of awe and appreciation for the beauty around you.
You walk to work, and you see that everyone else is doing the same. There are few cars on the road, and the ones that are present are autonomous and electric. The streets are cleaner, and there’s less noise pollution. You feel grateful that you don’t have to deal with traffic and the stress of navigating a congested city.
As you arrive at work, you notice that the building is powered by clean energy sources. There are solar panels on the vegetation-covered roof and a wind turbine in the distance. The air conditioning and heating systems are powered by geothermal energy, and there are plants and greenery throughout the office that help to purify the air.
At lunchtime, you head to a nearby park, and you notice the difference in the air quality. The air feels fresher, and you feel more energized. You see people walking, jogging, and biking around the park, enjoying the clean air and well-designed green space.
As the day comes to an end, you reflect on how both your mental and physical health has improved, and how the economy is now thriving. You feel a deep sense of connection to the natural world and the community around you.
In this world, you no longer fear the devastating impacts of climate change. You can live without the fear of rising sea levels, catastrophic weather events, and the adverse health effects of air, water, and noise pollution. You feel a sense of hope for the future, knowing that we created a better world for ourselves and for future generations.
this is not the world we currently live in.
We don’t have the infrastructure where clean energy sources support our infrastructure and our lifestyles. Every day we breathe in numerous air pollutants, proven to cause health issues from respiratory illnesses to lung cancer to heart disease. Yet we keep going about our days pretending that the world will magically clean itself up.
What if I told you that there is a viable option to slow global warming while maintaining our current lifestyles and enabling the development and scale-up of green energy sources?
What if I told you there is an opportunity to save lives, increase crop productivity and improve the health of ecosystems globally?
Here at Photonix, we understand that climate change is a complex problem that won’t be solved with one, or even a handful of isolated actions or solutions. However, we have developed an innovative, even revolutionary, approach to decrease the speed at which our planet is heating up, giving humanity time to learn and adjust while climate tech innovation catches up.
Our plan: direct a high-energy photons at the troposphere to initiate the photodissociation of ozone (O3) molecules, one of the major air pollutants, faster than it can reform, decreasing the insulating effect ozone has on Earth that contributes to global warming.
Sounds like science fiction? Allow us to explain.
Tropospheric ozone, also known as ground-level ozone or O3, is a colorless and highly reactive gas. On Earth, ozone is present in two main areas: the troposphere, ground-level to approximately 15km up, and the stratosphere, the upper layer of theatmosphere. In the stratosphere, ozone plays an important role in protecting Earth, and its inhabitants, from harmful ultraviolet radiation coming from the sun by absorbing them. However, ozone in the troposphere also absorbs heat and radiation coming from the Earth, and acts as a greenhouse gas/air pollutant, effectively increasing global temperature.
Tropospheric ozone is considered a secondary pollutant as it is not directly emitted into the atmosphere, but is formed through reactions between nitrogen oxides (NOx) and volatile organics compounds (VOCs), also known as hydrocarbons, in the presence of heat and sunlight. The pollutants contributing to the creation of ozone are typically emitted by vehicles, factories, and burning fossil fuels among other man-made sources.
Besides directly contributing to global warming, tropospheric ozone also negatively impacts Earth’s climate in other ways such as tampering with evaporation rates, cloud formation, precipitation levels, and atmospheric circulation. These specific impacts disproportionately affect the Northern Hemisphere as it contains the regions where the majority of tropospheric ozone precursors are emitted.
On the ground level, tropospheric ozone significantly reduces crop yields, negatively effects growth, seed production, the absorption of atmospheric carbon by plants, reduces functional leaf area and hastens the aging process.
These issues result in over $20B+ lost in crops that can’t adapt to our changing climate each year.
As a result of ozone’s effects on plants, important ecosystem services provided byplants are also impacted. Examples of this include food security, carbon sequestration, timber production, and protection against soil erosion, avalanches, and flooding.
Now, to the exciting part: how directing photons at the troposphere will initiate the decomposition of ozone.
The laser we will be using to decompose tropospheric ozone is a version of a krypton-fluoride (KrF) excimer (short for ‘excited dimer’) laser.
For our laser, we are using krypton and fluorine as the lasing medium, and an electrical discharge as a source of energy. When an electrical discharge is applied to the elements, the following steps occur:
The krypton fluoride laser absorbs energy from a source, causing the krypton gas to react with the fluorine gas producing the excited complex krypton fluoride, a temporary complex in an excited energy state:
2 Kr + F2 → 2 KrF
The complex undergoes stimulated emission, reducing its energy state to a metastable, but highly repulsive ground state. The ground state complex quickly dissociates into unbound atoms:
2 KrF → 2 Kr + F2
The result is an exciplex laser that radiates energy at 248 nm, near the ultraviolet portion of the spectrum, corresponding with the energy difference between the ground state and the excited state of the complex.
The range that the KrF laser could potentially reach depends on factors such as the environment. If there is a high amount of humidity or dust in the air, then the wavelength would be shorter because it would take more energy to pass through all those molecules.
On a clear day, a KrF laser could reach approximately five kilometers into the troposphere. This could clear the troposphere because once the laser comes in contact with the bottom of the molecules in the troposphere, the oxygen molecules separating would create a chain reaction eventually reaching higher molecules in the troposphere.
To begin, the photodissociation of ozone in the presence of nitrogen at 248 nm can be described by the following steps:
1. Ozone (O3) absorbs a photon of UV radiation with a wavelength of 248 nm (hv) which provides enough energy to dissociate the molecule and produce O(1D), a single oxygen atom in an excited state, and O2, molecular oxygen:
O3 + hv → O2 + O(1D)
The excited O(1D) atoms are short-lived and can interact with other atmospheric species, such as nitrogen, oxygen, and water vapor, as they have more energy to initiate chemical reactions. The following chemical reactions either regenerate ozone or lead to its depletion.
2. The excited oxygen atom, O(1D), formed in step 1 can now react with nitrogen molecules to form nitrogen oxides and oxygen:
O(1D) + N2 → NO + N
O2 + N → NO + O
3. The nitrogen oxides formed in step 2 can then react with ozone, leading to its destruction:
NO + O3 → NO2 + O2
NO2 + O → NO + O2
4. The nitrogen oxide molecules produced in step 3 can react with atomic oxygen (O) to regenerate the NO molecule, which can then react with more ozone, leading to further destruction:
NO + O → NO2
NO2 + O3 → NO + 2O2
These reactions ultimately lead to a decrease in the amount of ozone in the atmosphere, and by doing so, we help the planet help humanity in return.
By decreasing the concentration of ozone in the troposphere, we reduce the greenhouse effect it has on the planet and improve air quality on a global scale. When air quality is improved, the annual number of premature deaths caused by ozone decreases, saving and prolonging the lives of vulnerable populations. By reducing the greenhouse effect, crop yields improve and plant aging processes decelerate to a normal pace. When ecosystems begin to recover, the likelihood and frequency of natural disasters diminish, saving more lives and hardship for vulnerable populations.
To begin this cycle of healing for the planet and population and to maximize the the potential of this solution, there are four main regions to target: urban areas, agricultural regions, ecologically sensitive areas, and developing countries.
1. Urban areas:
Urban areas are often the most heavily impacted by tropospheric ozone due to the high levels of nitrogen oxides (NOx) and volatile organic compounds (VOCs) emitted by vehicles and industrial sources.
Implementing ozone reduction strategies in urban areas could have significant positive impacts on human health. Tropospheric ozone is known to cause respiratory problems, aggravate asthma, and increase the risk of heart disease. By reducing ozone levels in urban areas, we can help to improve air quality and protect the health of residents.
2. Agricultural regions:
Tropospheric ozone damages crops and reduces yields, significantly impacting agriculture and food security. Reducing ozone levels in agricultural regions could help to protect crops, improve crop productivity and quality, ensure food security, and decelerate the crops’ aging processes to normal levels. It could also potentially reduce the need for expensive inputs such as fertilizers and pesticides.
3. Ecologically sensitive areas:
Tropospheric ozone harms ecosystems by affecting the growth and health of plants and other organisms. Implementing ozone reduction strategies in ecologically sensitive areas, such as national parks and wildlife reserves, would help to preserve biodiversity and protect the health of sensitive ecosystems. It could also have positive economic impacts by supporting ecotourism and other sustainable industries.
4. Developing countries:
Developing countries often have high levels of air pollution, including tropospheric ozone, due to a lack of environmental regulations and limited access to clean technologies. Reducing ozone levels in developing countries could have significant positive impacts on human health and economic development. It could also help to mitigate the negative impacts of climate change, such as natural disasters, and promote global sustainability.
Here at Photonix, we want to democratize clean air and a healthy planet.
By taking a holistic approach to make the earth a cleaner space, not only will the bottom billions not be left behind, but society leaders will also benefit economically by living in a time where climate action spurs innovation and new opportunities for humans to grow and evolve. If you believe in our vision to make the world a healthier and more sustainable place for future generations, join us at Photonix to make a systematic change one photon at a time.
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