Imagine a future where, despite all our efforts to curb greenhouse gas emissions, global temperatures are sky-high, the glaciers are melting, and several other repercussions are slamming the earth, one by one. That day is not far off. Already, compared to the 1800s, the Earth is about 1.1°C warmer (see Figure 1). Global temperature is projected to rise by about 1.5 degrees Celsius by 2050 and by about 3 degrees Celsius by 2100 if we are not careful. The Paris Agreement's goal to cap the rise of global temperatures at about 1.5°C to fight global warming, is highly unlikely to be met if the current policies and methods continue.
We can’t wait any longer. We must start implementing drastic measures soon.
3 astrophysicists recently came up with the wild idea of shooting Moon dust into the space between Earth and the Sun that may act as a barrier to protect the earth from intense solar radiation. Researchers believe this measure could reduce the power of sunlight by more than 1.5%. This is supposed to be one of the ways of geoengineering the planet. So, what exactly is Geoengineering?
Geoengineering refers to the emerging technologies that are currently being developed to counter global climate change. It can be broadly classified into 2 types - Carbon Geoengineering or Carbon Dioxide Removal (CDR) and Solar Geoengineering or Solar Radiation Management (SRM).
Carbon Geoengineering aims to reduce the carbon dioxide content in the atmosphere through its removal.
Solar Geoengineering involves reducing the intensity of sunlight reaching the earth by reflecting some of it back into space, thereby attempting to cool the planet.
The idea of solar geoengineering is gaining popularity in many developed nations. In the year 2021, a report by the US National Academy of Sciences suggested that the United States form a coalition to conduct a detailed study on the viability of solar geoengineering as a stopgap measure to address the global climate change crisis.
Solar Geoengineering can be accomplished with the help of several climate resilient technologies, such as roof coatings, orbital mirror installations, stratospheric aerosol injection, marine cloud brightening, cirrus cloud thinning, space-based techniques, and other methods.
Solar Reflective Roof Coating involves the application of radiation-reflective paints onto the rooftops of large buildings to decrease the temperatures within the buildings. The French Startup Cool Roof France has developed this green cooling technology which has a reflective, thermal white paint that prevents buildings from getting overheated and reduces the need for ACs, which can cut down on CO2 emissions.
Marine Cloud Brightening is a method in which marine clouds or the low clouds hanging over the ocean are made to reflect sunlight back into space by spraying them with sea salt.
Cirrus Cloud Thinning involves seeding the high-altitude atmospheric clouds with aerosol particles to thin them out so they don’t trap much heat within and also emit long-wave radiation from the earth back into space.
Space-based Technologies involve placing sun shields in space that reflect sunlight away from the earth.
Stratospheric Aerosol Injection is an attempt to scatter sunlight back into space by introducing tiny reflective particles like sulfate aerosols or calcium carbonate particles into the upper atmosphere (see Figure 2). It can be done using aerostat systems, such as balloons or specialized airplanes. The US startup Make Sunsets claims to have sent up two weather balloons filled with helium and Sulphur dioxide above Mexico’s Baja California recently. There they are said to have burst, dispersing sun-reflecting sulfur dioxide particles into the stratosphere and cooling the Earth a bit.
Of all the different types of solar radiation modification that have been proposed, stratospheric aerosol injection is considered to be the cheapest and the most effective.
Research data on the basis of environmental intelligence platforms has shown that the deliberate use of solar geoengineering along with cuts in greenhouse gas emissions can reduce global warming. Solar geoengineering could –
However, this novel technology also comes with risks and uncertainties. While research may have shown us its impact on a global scale, it is hard to ascertain how this will affect grassroots communities. Since we are literally intervening in the natural course of events when it comes to solar geoengineering, we are still in the dark about how all of this might eventually pan out in the future.
Open Philanthropy, a venture of billionaire Dustin Moskovitz, a co-founder of Facebook and Asana, is funding scientists across Africa, Asia, and South America to study the feasibility of solar geoengineering to combat global warming.
The Royal Society reports that more than scientific or technical obstacles, what holds back a full-fledged deployment of solar geoengineering might be the social, ethical, regulatory, legal, and political issues associated with it, especially in the current international political system. Governments need to come to a consensus on complex decisions such as the places where the technology can be deployed, the manner in which it can be conducted, the degree of cooling that needs to be accomplished, the duration of deployment, and who is responsible if something goes wrong, as solar geoengineering is bound to impact all nations. The poorest and the most vulnerable nations must be given a voice in decision-making when it comes to solar geoengineering. Around 700 million people live in dire circumstances. About 800 billion people worldwide suffer from hunger. These people will be hit the hardest if there is any change in their environment.
The world will soon surpass the threshold of global warming. If so, there won’t be any end to flooding, torrential downpour, drought, wildfires, or other calamities like food shortages. Solar geoengineering can alter the Earth's radiative balance but it won’t do much to change the concentrations of greenhouse gases in the atmosphere, which are the real culprits of global warming. The most appropriate strategy to overcome the harmful effects of environmental pollution is to first address the root cause of global warming. And that, according to research, necessitates the immediate reduction of greenhouse gas emissions such as carbon dioxide, methane, and others.
The use of green energy such as solar energy, wind energy, hydroelectricity, and tidal are preferable over fossil fuels as they are environmentally friendly. Green energy is derived from renewable resources like water, wind, and sunlight. They are locally available, unaffected by political turmoil or supply chain disruptions, and emit little to no greenhouse gases. Solar geoengineering might not reduce emissions or provide clean energy or help in environmental conservation. Like the treatment of chemotherapy for cancer, solar geoengineering is dangerous, it is unpleasant, yet it needs to be done, as the alternative, global warming, can be worse. Time is ticking and the doom will soon be upon us. Solar geoengineering can help us buy some time. Here is a glimpse of the markets associated with solar geoengineering (see Figure 3).