Geoengineering: Solar Radiation Management

Solar Radiation Management Overview

Solar radiation management, according to the Solar Radiation Management Government Initiative (SRMGI 2018), is an approach to theoretically remove some effects climate change has on the Earth by reflecting incident sunlight back out into space.  The effects of solar radiation management are to not reduce the amount of greenhouse gas concentrations in the atmosphere as the previous method (carbon dioxide removal) mentioned, however, instead this method paves ways to reduce rising global temperatures.  There are many ways in which solar radiation management could be implemented which include space-based and surface-based operations.

Solar Radiation Management:  Space-Based Operations

Space-based solar radiation management, as the name indicates, takes place in outer space.  Space-based operations would be an attempt to block portions of sunlight before it reaches the Earth’s atmosphere.  According to Pluijm (2017), solar radiation management would help to offset the warming effects of greenhouse gases by allowing the Earth to absorb decreased amounts of solar radiation.  Reflecting solar radiation can be done through one way which is the utilization of space mirrors (see Figure 2).  Reflecting solar radiation using space mirrors was first proposed by, according to Kaufman (2012), Lowell Wood of Lawrence Livermore National Laboratory.  Wood proposed the use of an enormous mirror or a multitude of mirrors to deflect sunlight back into space.  Wood calculated that even by deflecting a mere one percent of sunlight would significantly reduce the effects of climate change.  The space mirror in question would have to be enormous and roughly have an area slightly smaller than Greenland, at six hundred thousand square miles.  Launching something like this would be nearly impossible due to not only the size, but the cost.  An effective way to implement this device would be to build it in space, which may risk the lives of the engineers who build it.  Also, a mirror this size would be extremely difficult to maintain.  Debris from broken satellites, small meteorites, comet tail debris, and other facts would make this a nightmare to maintain and build.  Thankfully, other measures have been investigated.

Figure 2 for GCC Blog Post 2
Figure 2:  Depicts a giant space mirror reflecting sunlight back into outer space away from the Earth.


According to Kaufman (2012), another option was proposed in 2002 by a space consulting firm known as Star Technology and Research.  This option explored the idea of creating a network of steerable mirrors that would orbit Earth’s equator.  According to the calculations, this network could lower the average global temperature by as much as three degrees Celsius (or 5.4 degrees Fahrenheit), while at the same time, using onboard solar panels to harness the energy captured and sending that energy to a facility on Earth.  However, a major problem arises within the idea itself.  To obtain the effect of dropping the average global temperatures by three degrees Celsius, the president of Star Technology and Research Jerome Pearson, according to Kaufman (2012) stated that it would take nearly five million spacecrafts to generate such a result, which means, in terms of repairs, approximately one hundred thirty-seven of these spacecrafts would need replaced or repaired daily.  Since both these ideas are most likely unrealistic with modern day technology, we must explore other ideas (Kaufman, 2012).

Solar Radiation Management:  Surface-Based Operations

Many ideas have been investigated to help reduce the effects of climate change.  Idea that have been discussed include changing the color of rooftops on a multitude of structures and by adding reflective sheets in desert areas.

Solar Radiation Management:  Reflective Rooftop Colors

             In recent studies, according to Biello (2014), painting rooftops white may offset the effects of global warming (see Figure 2).

Figure 1 for GCC Blog Post 2
Figure 2:  Depicts the albedo of various rooftop surfaces.

According to Georgescu et al (2013), by painting rooftops white, we can reflect more sunlight back out into space, which, in turn, can offset warming due to urban expansion.  Urban expansion is currently contributing to the effects of global warming.  The albedo of a surface is, according to the National Snow and Ice Data Center, a non-dimensional, unitless quantity that represents how well a surface can reflect sunlight.  The albedo of a surface ranges from zero to one; zero being a black surface which completely absorbs incident radiation and one being a white surface which completely reflects incident radiation  As more buildings and other structures replace forests and trees, the average temperature in that area rises due to the urban heat island effect.  The urban heat island effect is an urban area that is much warmer than the surrounding rural areas due to increased human activity.  According to models developed by the Environmental Protection Agency (EPA), the amount of urban areas within the United States may increase by as much as one million square miles by 2100.

The idea of implementing the color changes would have, at least, some effect on the average global temperature rise.  For example, according to Biello (2014), New York City contains one hundred square kilometers of black-colored rooftops.  These black-colored rooftops allow the heat to be absorbed, thus making New York City hotter.  As part of the Cool Roofs project, volunteers in NYC have been changing the color of the rooftops from black to white to enhance the reflection of sunlight to produce a cooling effect.  However, according to Biello (2014), only five hundred square meters of roof have been painted thus far, which amounts to less than one percent of NYC’s rooftops.  This idea, although intriguing and possibly effective, proves to be a hard-to-achieve method due to lack of support from communities.  However, another method has been discussed recently.


Solar Radiation Management:  Reflective Sheeting in Desert Areas

The implementation of adding reflective sheeting in desert areas seems like a radical idea, however since desert regions receive large amounts of sunlight, adding reflective sheeting in these areas may help reduce the effects of global warming.  By adding reflective sheeting to deserts, the albedo can be altered.  By adding reflective sheets within desert regions, we can effectively raise the albedo, thus allowing for the reflection of more sunlight.  However, due to increased carbon dioxide levels within Earth’s atmosphere, this method, although reducing incoming solar radiation by 1.74 watts per meter squared, would not mitigate the Arctic shrinkage (see Figure 3), which is one of the major effects resulting from global warming.

Arctic Shrinkage Figure
Figure 3:  Depicts the shrinkage of the Arctic ice from 1979 (left) to 2011 (right).


Overall, many ideas have been discussed to increase the reflection of sunlight back into outer space, however most of the ideas are either too expensive, nearly impossible to achieve, or do not counteract varying effects of climate change.  However, the next blog will focus on ways to increase cloudiness in particular regions, which may help reduce global temperatures as well as deflect sunlight away from the ice caps and other ice-covered regions on planet Earth.

Linked Articles

Cool Roofs Might Be Enough to Save Cities from Climate Overheating (Biello, 2014)

Could Space Mirrors Stop Global Warming (Kaufman, 2012)?

Editor’s Vox:  Good Night Sunshine:  Geoengineering Solutions to Climate Change (Pluijm, 2017)?

Fix for Global Warming?  Scientists Propose Covering Deserts with Reflective Sheeting

Solar Radiation Management Governance Initiative

Thermodynamics:  Albedo

What is the Urban Heat Island Effect?




Geoengineering – Carbon Dioxide Removal


Climate Change Overview

Climate change is one of the world’s biggest problems.  Climate change just does not affect localized areas, it affects the entire globe.  Although climate change may impact some areas more than others, we, as a species, must act to prevent drastic changes from occurring.  Combating climate change can be and should be met with swift action.  Now, I know that there are some people that do not believe in climate change, and you are entitled to your opinion, however, according to the IPCC AR5 (Intergovernmental Panel on Climate Change Fifth Assessment Report) and previous assessment reports, changes in climate have been observed on all continents.  The fact that climate change is affecting all continents should be alarming.  As a species, we need to come up with a plan or a multitude of plans to combat climate change.  One way is through geoengineering efforts.

Geoengineering Overview

Geoengineering efforts may seem abstract to many people, and some of them are, however, there are many proposed ideas that may help reduce the effects of the rapidly changing climate.  These ideas include carbon dioxide removal (direct air capture, ocean fertilization, bio-energy with carbon capture and storage, and afforestation) and solar radiation management (increasing the planetary albedo).  Both methods and accompanying sub-methods seem very abstract, however I will be discussing these methods in detail.

Carbon Dioxide Removal

Carbon dioxide removal seems to be the easiest way in combating climate change, however, will the effects of this idea be enough to reduce the changing climate?  According to Kolbert (2017), the concentration of carbon dioxide in Earth’s atmosphere reached four hundred and ten parts per million, which is an amount far greater than any point in the mid-Pliocene era.  This staggering concentration of carbon dioxide is extremely alarming.  If the rise in carbon dioxide continues, the Earth could reach a point in which leads to a catastrophe.  Nevertheless, we as a species have the capability to reduce the carbon dioxide in Earth’s atmosphere through many means, with the first being direct air capture.

Carbon Dioxide – Direct Air Capture

Direct air capture of carbon dioxide may prove to help reduce the effects this greenhouse gas has on Earth’s atmosphere.  A greenhouse gas, according to the AMS, is a gas that effective traps heat, thus controlling the surface temperature of the Earth by absorbing infrared radiation emitted by the Earth and the atmosphere.  Direct air capture of carbon dioxide is done through the photosynthesis process of plants.  If plants can remove carbon dioxide through a method of photosynthesis, we, as a species, should also find ways to do the same.  According to Magill (2017), a Swiss company by the name of Climeworks is set to begin the process of removing carbon dioxide directly from the atmosphere.  The company set a goal to attempt to remove one percent of carbon dioxide emitted annually by 2025.  By taking this step, Climeworks can become a leader in the field of carbon dioxide removal to reduce the amount in Earth’s atmosphere, thus attempting to prevent furthering the changes in climate that have already been observed.

Carbon Dioxide Removal – Ocean Fertilization

Another method that can prove to be a leader in the innovative geoengineering efforts proposed to combat climate change is ocean fertilization.  Ocean fertilization occurs by injecting nutrients into the upper ocean.  The goal of ocean fertilization is to enhance the production of marine food as well as removing carbon dioxide from the atmosphere.  Please see figure 1 on how carbon dioxide is pumped in and out of the ocean/atmosphere.


Carbon Pumping
Figure 1:  Depicts the carbon dioxide sequestration in the ocean.

Ocean fertilization can primarily be done by iron fertilization.  Iron fertilization helps phytoplankton to grow.  Phytoplankton, according to NOAA, are microalgae that can remove carbon dioxide from the oceans.  Iron fertilization, according to Waller (2012), allows phytoplankton to grow due to iron being a major nutrient.  According to Coale et al (1995), a study of iron fertilization was done as an in-situ experiment, giving rise to the injection of iron near the Galapagos Islands.  Overall, this experiment showed that by injecting iron near the Galapagos Islands, the phytoplankton levels increased by nearly three times in the experiment.  Since the experiment was a success, the topic of ocean fertilization using iron was created.

Carbon Dioxide Removal – Bio-Energy with Carbon Capture and Storage (BECCS)

BECCS is a process in which large-scale removal of carbon dioxide is combined with renewable energy to remove vast amounts of carbon dioxide from primary sources.  BECCS came into existence through the planting of various types of trees and vegetation that remove carbon dioxide from the atmosphere.  The carbon dioxide taken in from these trees and various vegetation types is then injected into geologic formations.  This is because geologic formations can hold carbon dioxide for longer periods of time.  BECCS set a goal to remove ten gigatons of carbon dioxide annually, however the cost is not cheap.  The cost to remove one ton of carbon dioxide is approximately $60 to $250 dollars.  In order to meet the goal the BECCS set, the cost would be approximately $600 billion to $2.5 trillion dollars annually.  BECCS would most likely be a very efficient way to remove carbon dioxide from the major industries in the modern world, however, most countries cannot afford the bill that comes along with it.

Carbon Dioxide Removal – Afforestation

An alternative method to BECCS is afforestation.  Afforestation is the planting of trees and other various types of plants in areas that previously did not have any trees and/or plants.  Afforestation may not be enough to counteract the ongoing deforestation that has taken place or is currently taking place in Europe, China, Brazil, and other countries around the world.  Countries that have engaged in afforestation are Israel, Japan, and Australia.  As the demand for building materials and wood fuels increases, the deforestation occurring across the world also increases.  As afforestation techniques take place, climate change can be met with a foe that will slow the process down.  However, since climate change covers a wide variety of factors, afforestation may not be enough to combat climate change.  Nevertheless, countries across the globe should participate in this technique.


Within this post, various methods pertaining to carbon dioxide removal were discussed.  In the next post, methods of solar radiation management will be discussed.  Overall, we as a species, have at our disposal, many techniques to combat climate change.  However, only a handful of countries across the globe have decided to take the steps to ensure the implementation of these ideas.  Hopefully in the future more countries will join and take a stand against this multi-generational problem known as climate change.  If any of these topics peak your interests, please see the Linked Articles section below for more details.

Linked Articles


Select “Full Report” under the “Quick Links” section

Can Carbon Dioxide Removal Save the World (Kolbert)?

Direct Air Carbon Removal – Swiss Company

Iron Fertilization:  Savior to Climate Change or Ocean Dumping (Waller)?

IronEx-I an In-Situ Iron-Enhancement Experiment (Coale et al)

The History of BECCS

Afforestation:  Meaning, Importance, and Current Efforts

The Journey Begins

Hello, everyone, I hope all is well!  I wanted to give a brief introduction as to the type of content you will see on my blog.  First and foremost, this is my first time creating a blog, therefore my experience is quite limited, however I am eager to learn!  Also, I am wrting my first blog on the topic of climate change for my Global Climate Change course here at California University.  The topic I have chosen is the topic of geoengineering.  I will be discussing various types of methods of geoengineering that may possibly help/hurt our efforts as a species to combat climate change.

Through these blog posts, I am going to be setting some rules.  The rules are as follows:

  • Please keep the vulgar language at a minimum.
  • I am open to discussing any topic related or unrelated to geoengineering as long as the topic pertains to climate change.
  • Please be respectful to others.  Everyone is entitled to his/her opinion, therefore let us all work together and respect each other.  Climate change is a topic that crosses borders and political party lines.  No matter you belief, we must try to come together as a species to prevent a disaster of these proportions from getting out of control.  For the first time, we as a species have the ability to remove and/or lessen the effects of climate change.  We should throw everything we have at it.
  • Lastly, if you would like to leave a comment, please do so on WordPress.  I will be posting my blog on other social media platforms such as Facebook, Twitter, Instagram, etc., however if you wish to leave a comment, please do so on WordPress.

Thanks for joining me and thank you for your support!

P.S. We all have to think about this problem, so why not think big?

You have to think anyway, so why not think big? — Donald J. Trump