Fixing the Global Carbon Crisis with Space Development
Jennifer A. Boltona*, Kim Peartb
a Space Pioneers Foundation, 39A Bridge Street, Ross, Tasmania, Australia, 7209, firstname.lastname@example.org
b Space Pioneers Foundation, 39A Bridge Street, Ross, Tasmania, Australia, 7209, email@example.com
* Corresponding Author
Presented by Dr Jennifer Bolton at the International Astronautical Congress in Washington, D.C., on 24 October 2019.
Climate change presents an immediate threat to Earth with the potential for a planet-wide disaster. The consequences of rising temperatures will be environmental, social and financial. No aspect of human society will be unaffected. There are serious implications for health, agriculture, business and security as climate refugees are driven from their homes. The space industry will not be immune from these effects with less resources available for space development as the world is forced to divert more attention and assets to coping with climate change. Fortunately, space science and industry are ideally positioned to contribute to solving the current carbon crisis. While climate change is a complex issue, reducing the level of carbon dioxide in the atmosphere is one clear way to reverse global changes. Technology exists and is currently deployed on a small scale to achieve carbon dioxide extraction from ambient air. The challenges are to scale up this process to reduce atmospheric carbon dioxide to a safe level and decide how to process the captured gas. There is already a market for carbon dioxide in industry and agriculture but this will not be able to absorb the volume of this gas that must be removed from the atmosphere. Ultimately, to avoid having to store large amounts of carbon dioxide it will need to be processed into carbon and oxygen for reuse or storage. Conversion of carbon dioxide to its elemental components is possible in the laboratory and current research seeks the most efficient way to achieve this on a large scale. To remove the volume of carbon dioxide from the atmosphere that will reverse dangerous climate change and reduce it to elemental carbon for reuse or safe storage will require a vast amount of energy that clearly must not be derived from fossil fuels. Space-based solar power can provide the solution. An integrated approach using the energy of the Sun harvested in space to extract carbon dioxide from the air and process it to elemental carbon would demonstrate clearly the value of space technology to human society and the Earth environment. Space Pioneers advocates for this approach to solving Earth-based problems. By considering the Solar System as a whole with its vast physical and energy resources, rather than viewing the Earth in isolation, it is possible to find solutions for the most pressing problems facing human society. The participation of the space community in this discussion is essential.
Keywords: climate change, space-based solar power
Climate change and global warming are caused by an increased amount of carbon dioxide (CO2) and other greenhouse gases in Earth’s atmosphere. Since the industrial revolution the level of atmospheric CO2 has increased from approximately 280 parts per million (ppm) to 410 ppm . The burning of vast quantities of fossil fuel to support a rapidly expanding population and increasingly technological society has been the single greatest contributor to these higher levels of CO2 . The chemical structure of the CO2 molecule permits it to absorb thermal infrared energy radiated from the Earth’s surface and then trap that heat energy, warming the planet . While an atmosphere capable of retaining heat energy is essential for life as we know it to exist on this planet, a rapid increase in global temperature disrupts climate systems and threatens many species with extinction .
There are multiple effects of global warming on planetary systems. The increased levels of atmospheric CO2 result in higher levels of CO2 dissolved in the oceans lowering the pH of the water and changing ocean chemistry . These changes have consequences for organisms with calcium carbonate body structures such as coral and sea urchins that suffer weakening of their shells . Higher global temperatures lead to rising sea levels due to thermal expansion and the melting of ice sheets . Changes in weather patterns also occur with a trend to more extreme weather events ranging from droughts to severe storms and flooding . The overall effect on society is a loss of stability and security. Agriculture will be impacted due to the changing climate and increased atmospheric CO2 levels resulting in decreased quality and quantity of some food crops . Increasing temperatures will expand the range of insect vectors such as mosquitos leading to more widespread cases of diseases formerly restricted to the tropics. The combined direct and indirect effects of global warming on human health will see a significant increase in morbidity and mortality. As heat, rising sea levels, extreme weather events and food and water shortages begin to make some areas uninhabitable, climate refugees will begin to move anywhere that provides some respite from the worsening conditions .
2. Material and methods
A literature review has been conducted to investigate the potential for space development to assume a leading role in climate change mitigation.
The approaches used to counter climate change fall into two main categories: mitigation and adaptation. Mitigation involves reducing sources of greenhouse gas emissions and increasing sinks for CO2 capture such as through re-forestation while adaptation seeks to prepare the world for a hotter future . Although most mitigation has focussed on reducing reliance on fossil fuels to meet lower greenhouse gas emissions targets there has also been interest in the possible role of climate engineering, also known as geoengineering, to reduce the impact of climate change. Climate engineering approaches can also be divided into two main categories: greenhouse gas removal and solar radiation management . One earth-based proposition for greenhouse gas removal is to increase CO2 sequestration from the atmosphere by promoting increased growth of phytoplankton through ocean fertilisation, most commonly with iron, although the use of other nutrients has also been proposed . Additionally, solar radiation management through the introduction of sunlight-reflecting sulfate aerosols into the atmosphere is suggested as a way to cool the planet although it will do nothing to mitigate the ocean acidification occurring due to increased absorption of CO2 . These methods of climate engineering are relatively easy and inexpensive to employ but once initiated cannot be simply reversed creating a risk of unavoidable, and as yet not fully understood, side effects [8,9]. Ocean fertilisation and sulfate aerosol injection into the atmosphere are examples of large-scale climate interventions that utilise only the resources of the Earth to seek a solution to a planet-wide problem. Shifting the focus to space provides an opportunity to develop solutions that draw on the far greater resources available beyond our home planet.
4. Results and Discussion
The most direct way to lower the atmospheric CO2 concentration is to extract it from the air. A number of groups have developed ambient air CO2extraction technology and several pilot plants are already in operation [10,11]. Research has focussed on scaling up this process to a level where it can begin to make a meaningful impact on global warming but has been limited by energy demands and economic considerations. Forcing CO2 extraction technology to prove its worth in the context of using only Earth-based resources to supply the required energy, including ground-based solar power, is an unreasonable restriction. The primary aim should be to remove more CO2 from the atmosphere than is generated by the extraction process. This can be more readily achieved by drawing on the resources of space, specifically space-based solar power, than by using current methods. The potential of generating solar power in space for use on Earth was proposed in 1968 . The benefits of space-based solar power generation over ground-based methods include continuous availability, no atmospheric attenuation of the solar energy and no seasonal or weather effects. A project to develop space-based solar power for the purpose of enabling atmospheric CO2 extraction could go one step further and consider processing captured CO2 to give elemental carbon and oxygen. While CO2 has many uses in industry and agriculture , if large scale CO2 extraction can be achieved the amount of CO2 recovered from the atmosphere will exceed industrial demand. Long-term storage of extracted CO2 is not desirable due to the risk of leakage and escape back into the atmosphere . Recent research into storing extracted CO2 as carbonate minerals in basaltic rocks shows it has promise as a stable disposal method , but an alternative would be to separate CO2 into carbon and oxygen for reuse. The liberation from energy restrictions provided by space-based solar power would boost the chances of successfully integrating CO2 extraction with processing to carbon and oxygen. The CO2 molecule is very stable and any methodology used to separate it into its elemental components requires a significant input of heat and/or electrical energy . A recent study demonstrated the possibility of CO2 reduction to solid carbonaceous species at room temperature in the laboratory  but large-scale processing is currently limited by energy requirements. By harnessing space resources it not only becomes possible to extract CO2 from the atmosphere without use of fossil fuels but to also convert CO2 into useful products improving the economic viability of the process.
A controlled way to cool the Earth would be by deploying an adjustable sunshade in space. As with the proposals for sulfate particle injection into the atmosphere, this approach would cool the planet without reducing the CO2 concentration and so would not counter ocean acidification. A sunshade would provide relief from the heat while other measures such as atmospheric CO2 extraction lowered the concentration of this greenhouse gas. Rather than increasing the planet’s albedo as occurs with Earth-based solar radiation management, the sunshade would deflect solar radiation before it reaches the atmosphere . The key requirement for a sunshade would be a design that allows adjustability to permit careful regulation of the planetary cooling effect. One possible configuration is multiple occulting disks positioned near the Sun-Earth Lagrange L1 point that could potentially double as energy collectors for solar power that is subsequently beamed to Earth .
The role the space industry could play in the battle against climate change would be very much to their own advantage. As more government funds are diverted to climate change adaptation and mitigation strategies, there will be fewer resources available for science and technology projects not seen to be contributing to solving this most pressing global problem. In the United States democratic presidential candidates have been promising trillions of dollars to combat climate change . The commercial sector is also increasingly allocating a proportion of their budget to countering the effects of global warming. The effect of these changing economics may be a reduction in funding available for space development unless the sector can demonstrate its vital role in the fight against climate change. As well as a loss of financial resources space development may also struggle to recruit the next generation to its ranks as young people worldwide march to protest inaction on climate change . There seems to be no recognition of the potential of space development to mitigate climate change and an active opposition to activities beyond the home planet demonstrated by the popular slogan “There is no planet B”. There is a risk that space may lose its relevance for the young as they focus on the environmental damage to the planet and seek to reverse this through using less resources.
Despite the many ways in which space already contributes to climate and environmental sciences there is a need for a more proactive approach by the space community to put their hands up and offer to help solve the global warming problem. Too often space is seen as separate from Earth, a place where the lucky few may escape to if conditions deteriorate on the home planet. A far better view is to consider Earth in the context of the whole Solar System and all the resources it contains. The management of our planet needs the overview that space provides, the vantage point from which new solutions to old problems can be seen. Using space-based solar power to provide the energy to extract and process CO2 from the air may not only solve the carbon crisis but also secure a pivotal role for space development in caring for the Earth for generations to come.
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