I have been studying the science of global warming with a passion since the late 1970s and earned a degree in Environmental Science in 1992.
Proposals To Engineer a Reduction in Global Warming
There is a growing consensus that humans need to prepare for a world in which the average global temperature rises to and surpasses a level at which serious impacts occur from permanent flooding of low-lying coastal areas to large-scale droughts in crop-growing regions to significant stresses on human health. Preventing further releases of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) is proving to be difficult. For this reason, scientists are proposing a number of engineering solutions to mitigate climate change and reverse the worst effects of global warming. Whether the proposed solutions are practical and can be implemented at a reasonable cost has yet to be determined.
The engineering solutions proposed to stop and reverse global warming fall into two broad categories: removing CO2 from the atmosphere and reducing the amount of sunlight that reaches or remains in the Earth's atmosphere. Both approaches would theoretically stop the global warming trend and over time reduce average global temperatures. The various solutions could be implemented in conjunction with each other to achieve maximum impact. Implementing them would require a broad scientific consensus and significant international cooperation.
Per the United Nation’s International Panel on Climate Change (IPCC), to avoid the worst impacts of global warming humans must limit the ongoing global temperature rise to no more than two degrees Celsius compared to the average global temperature during the middle 19th century, which is when human industrialization started pouring global warming gasses into the atmosphere. As of this writing, average global temperatures are about halfway to the two-degree Celsius increase threshold.
A Rendering of a Carbon Capture System
Solutions That Remove CO2 From The Atmosphere
The following solutions would in theory stop and eventually reverse global warming by removing CO2 from the atmosphere, reducing its warming effect on the Earth’s atmosphere.
Phytoplankton and Iron Enrichment In Oceans
Oceans are an enormous carbon sink, meaning they can hold a lot of CO2 and keep it out of the atmosphere. Living organisms in the oceans use photosynthesis to soak up and store CO2 while they are alive. When they die, they sink to the bottom of the oceans with the CO2 they captured during their lifetimes, keeping CO2 out of the atmosphere.
Algae known as phytoplankton are plentiful in the oceans and can be made even more plentiful by adding iron to seawater. Scientists are proposing helping phytoplankton multiply and grow rapidly in the oceans by providing them iron, thus increasing the amount of CO2 they capture while alive and store in the oceans when they die. Of course, altering the oceans' ecosystems by helping phytoplankton multiply and grow is not without controversy since nobody knows what effects it would have on marine life overall.
Construction of Massive CO2 Filters For Sequestration
There are several development efforts underway to create massive filtering systems capable of removing CO2 from the atmosphere in sufficient quantities to reduce atmospheric concentrations of this greenhouse gas. Once removed, CO2 can be turned into stone to keep it out of the atmosphere for millions of years. Of course, there are roadblocks to implementing this solution. First off would be obtaining the energy needed to run the massive filters and process the CO2 into stone. The energy would have to come from non-carbon based renewable energy sources. Secondly, there would need to be an economic incentive for the company that runs the CO2 filters and produces stone.
Plant a Massive Number of Trees
One of the least technical ways of removing CO2 from the atmosphere is to simply plant a massive amount of trees and let them do their thing, as they pull CO2 out of the atmosphere and sequester carbon. While this is a real solution, it does have a practicality problem. The area of new trees would need to be at least the size of Canada by some calculations, which is an enormous area. While this is not an impossible feat, it would take quite a coordinated global effort to find sufficient land in areas that receive adequate rainfall, so the newly planted trees would survive.
Massive Space Mirrors Could Reflect Sunlight Away From Earth
Solutions That Reduce The Amount of Sunlight Impacting the Earth
The following solutions would in theory stop and eventually reverse global warming by reducing the amount of energy from the sun that reaches or remains in the Earth’s atmosphere, which would reduce its warming effect on the Earth’s atmosphere.
Inject Man-Made Aerosols Into The Earth’s Stratosphere
When a volcano called Mount Pinatubo in the Philippines erupted in June 1991 it injected aerosols that consisted of dust particles and sulfur dioxide (SO2) into the Earth’s stratosphere. The aerosols spread throughout the stratosphere and reduced the amount of sunlight reaching the Earth’s atmosphere and surface by approximately 10%. This caused a reduction in global temperatures of approximately 0.6 degrees Celsius (1.0 degrees Fahrenheit) for fifteen months after the eruption.
Scientists have proposed mimicking the volcanic aerosol cooling effect by injecting large quantities of man-made aerosols into the stratosphere to block sunlight and cool the global average temperature. Physical experiments by researchers from Harvard University have started on a small scale to determine the feasibility of this approach. Implementing it on a world-wide scale would require a massive effort.
Increasing the Earth’s Albedo Effect
One of the ways Earth naturally controls its temperature is by reflecting some of the sunlight that reaches the Earth’s surface back into space. This reflection of solar energy is known as the Earth’s albedo effect. Albedo is a Latin word that means “whiteness.” Since the color white reflects more sunlight than any other color, having more ice and snow on the Earth’s surface and more white clouds in the atmosphere has a cooling effect on Earth’s climate.
One of the ways to increase the albedo effect would be somewhat controversial since it would require cloud seeding to increase white clouds, which could have unintended consequences on rainfall patterns and amounts. Another way that the albedo effect could be increased is by placing large reflective materials on unused lands to reflect sunlight back into space. This approach would certainly be somewhat controversial as well, since laying a large amount of man-made materials on the Earth’s surface would surely be disruptive to a local environment.
Install Large Reflectors Above The Earth In Space
One way to avoid the controversies associated with some of the Earth-based approaches would be to build large reflectors outside of the Earth’s atmosphere in space. While this engineering solution to global warming might theoretically be effective at reducing the amount of sunlight that reaches the Earth’s atmosphere and surface, it has other limitations. First off, it would be extremely expensive to design, build, and install massive mirrors in space. It could also present a physical hazard if it ever came crashing down to Earth due to an asteroid impact or sabotage. This approach may not be practical, but if global warming is spinning out of control and ravaging the Earth in the coming decades, the will might be found to implement it and many of the other proposed solutions to global warming.
Global Warming Geoengineering Poll
4 Megaprojects That Could Reverse Climate Change
© 2019 John Coviello
Devika Primić from Dubrovnik, Croatia on December 08, 2019:
The climate is bothered by this and your ideas sound useful.
Liz Westwood from UK on December 07, 2019:
You propose innovatove and radical solutions to climate change in this article. It encourages us to consider other options.