The year is 2050. World leaders convene to discuss methods to negate the rapidly rising global temperatures as another category 6 hurricane finishes ravaging the southeastern United States. By now, much of Indonesia and Oceania have been forced to relocate to other parts of the world due to rising sea levels, and droughts across Europe and China have made food a luxury for our exploding population. Though less of the world lives in extreme poverty compared to previous decades, rapidly advancing second world nations are turning to fossil fuels as a cheap, reliable power source, churning more CO2 into the atmosphere than ever before. We finally understand the dire consequences of our past inaction towards switching to a renewable energy economy, but it is too late now. Instead, humanity will spend the better part of the next century playing catch-up in an attempt to lower the Earth’s temperature in unorthodox ways to reverse the nasty effects of global warming.
Four scientists step forward with four unique, albeit lazy, ideas to lower the Earth’s rampant fever by at least 2⁰ C to return the planet to a healthy equilibrium. I refer to them as “lazy” not because they are easy to execute, but rather because these ideas are the consequence of being lazy as a species in the past. Each idea comes with their own risks and challenges far greater than if we hadn’t ignored the warning signs and switched to renewable power sources decades ago, but we are running out of options. If we don’t act soon, Earth’s rising temperatures and deadly climate changes will wash its surface clean of humanity. Taking a deep breath, scientist 1 steps up to the podium.
1. Reflect More Sunlight into Space
Scientist 1 notes that much of the Earth’s surface has been deforested, and urban land masses have grown exponentially in recent years. These darker man-made surfaces absorb more sunlight, converting it into infrared for CO2 to capture in the atmosphere. If we could coat these surfaces in lighter colored, more reflective materials, more visible light would be reflected into space unperturbed by the atmosphere, lowering the Earth’s effective temperature. Scientist 1 concludes that lowering the Earth’s temperature by 2⁰ C would require the blanketing of 15 million km² of Earth’s surface in a highly reflective material; comparable to the surface area of Russia. Even covering every man made structure in the world with perfectly reflective mirrors would not be sufficient to redirect enough sunlight back into space to lower our temperature. Scientist 1 therefore deems the most “elegant” solution for this method is immense floating platforms with white surfaces sailing the oceans, perhaps picking up ocean trash along the way. Still, to build enough of these ocean reflectors would take an enormous amount of manufacturing power.
2. Construct an Orbital Mirror
Scientist 2 straitens their tie and approaches the podium next. Scientist 2 notes the substantial drop in air temperature experienced during a solar eclipse, and uses this principle to back their lazy method of combating global warming. Between the Sun and the Earth, there is a place where their gravitational pulls cancel out and allow for an object to remain balanced in space directly between them. This “Lagrangian point” is technically unstable, but with some sort of maneuvering propulsion system, a large reflective object could be placed between the Sun and the Earth in order to redirect incoming solar energy elsewhere. Lowering the Earth’s effective temperature by 2⁰ C with this method requires that we block about 2.7% of the Sun’s cross sectional area with our orbital mirror. At the distance of Earth-Sun L1, such a mirror would have to have a diameter 2 times that of the Earth’s itself! This is obviously impractical. An alternative method would be a Halo ring of sorts, constructed around the Earth in a lower orbit which is always eclipsing a thin band of the planet. If built at an altitude of 200 km, this band would still have to be more than 3 km thick. Scientist 2 also notes that Master Chief would be disappointed in such a use of the Halo ring…
3. Introduce an Anti-Greenhouse Haze
Scientist 3 brings to light Saturn’s largest moon, Titan, which is colder than it’s supposed to be. After factoring in the moon’s solar flux, atmospheric properties, and greenhouse effect, Titan still has a temperature 9⁰ C below its expected equilibrium. This is due to the moon’s anti-greenhouse effect, attributed to its unique atmospheric haze. Organic molecules in Titan’s upper atmosphere not only block a notable fraction of visible light from reaching its surface, but also allow for infrared heat to be radiated away, causing its temperature to be lower than expected. Scientist 3 proposes such a solution for our planet, blocking the same 2.7% of the Sun’s light from before with an atmospheric haze, as opposed to an orbital megastructure. A metal dust, such as germanium, has a high reflectivity for visible light as well as a large transmittance in infrared wavelengths, allowing heat to escape the planet at a faster rate than it is let in. To lower the Earth’s temperature by 2⁰ C, 3 trillion tonnes (3*10¹² kg) of germanium dust would have to be deposited into the upper atmosphere. Scientist 3 also notes that this dust would have to be replenished every few years, and that they don’t know what health hazards such a dust would pose to humans.
4. Plant Trees
By 2050, 50 billion tonnes of CO2 is added to the atmosphere each year by human activities. Scientist 4 simply poses that we plant enough trees to absorb this excess CO2 in sanctioned areas where no humans are allowed to forest. Furthermore, they pose that this area be expanded proportionally to the both the rates rising CO2 emissions as well as deforestation. A full grown oak tree consumes ~1,500 kg of CO2 per year. To match rates of CO2 emissions, we would need to plant 34 billion oak trees (or trees of similar size); a land area requirement AGAIN proportional to that of Russia. And this is just to match CO2 emissions; to bring these levels down would require even more trees. Alternatively, Scientist 4 suggests that it may be possible to build factories to sequester CO2 directly out of the atmosphere. However, it would take millions of these anti-CO2 factories to even make a dent in CO2 emissions, and they would require a source of power to operate. If they can’t be operated by clean energy, Scientist 4 concludes that such machines would not be practical.
5. Just Wait
The politicians bicker and argue, but in the end they choose a 5th unspoken solution; to do nothing. They decide that all of the methods proposed are just too costly, risky, or unfeasible to carry out. Instead, they hope that a future generation will pick up the slack left to them by the previous generations of leaders to combat the effects of climate change. For our species, this is the most dire solution of all. Rising temperatures and a worsening climate eventually befoul our species, forcing us to either become annihilated by our own planet’s illness or move elsewhere in the galaxy to avoid our inevitable destruction. Once the last human has left the planet however, CO2 emissions stop. Machines deteriorate and technologies erode to give way to whatever life has survived the onslaught of humanity. Over the course of hundreds of years, trees outgrow abandoned cities and animals thrive in the ghost towns of our past. In the end, the planet equalizes on its own.
To combat the effects of global warming and climate change, we as a species need to act now. The easiest solution to global warming by far is right in front of our noses today; the switch from the firmly established nonrenewable energy market, to clean, reliable power sources. If we as a generation choose not to undertake this task ourselves, future generations will find it impossible to execute the same goal, even with alternative methods. We have been gifted this one beautiful planet to exist on. Though I hope that humanity one day lives on many planets in many star systems throughout the galaxy, we need to put in a certain amount of effort to ensure that our blue gem of a home remains a safe place for us, as well as all the life we share it with. Humanity needs Earth to survive, but it sure as hell doesn’t need us.
Originally published by Medium