Understanding how humans, animals, and other organisms exist on our planet but cannot do so outside of the Earth’s atmosphere has been the focus of many natural science studies for centuries. Ecology is one of the newest established natural sciences, and one of the leading areas of research in this field relates to the potential for ecosystems and how to create closed ecological systems. Here is an overview of what a closed ecological system is and whether they can save the future.
What is a Closed Ecological System?
A closed ecological system is best described as an ecosystem that does not rely on matter exchange with anything from outside of the system. Within these systems, if waste products are produced by one species, then they must be used by another species. The main purpose of a closed ecological system is to maintain life. Therefore, converting waste products into substances that are needed is essential. For example, urine, feces, and carbon dioxide must become water, food, and oxygen.
For a closed ecological system to work, at least one autotrophic organism is needed. Also known as a primary producer, an autotrophic organism is an organism that takes simple substances from its surroundings and produces complex organic compounds. This is usually done through photosynthesis or chemosynthesis.
Why Would We Need Closed Ecological Systems?
So far, the primary need to create closed ecological systems relates to creating a safe environment that can sustain life during space flights, in space stations, or at space habitats. In the foreseeable future, a closed ecological system use would relate only to use by those working in the aerospace industry or in scientific fields related to the environment or space. Despite the focus on biogenerative life support systems for space, there are also some potential future applications for these systems on Earth, says a report by Christian Tamponnet and Christopher Savage in the Journal of Biological Education. One relates to the potential creation of a closed ecological system to support life on either the moon or Mars in the event of a disaster on earth. The second is to create a closed ecological system that supports life on Earth if the situation with the atmosphere worsens and it becomes difficult to sustain life on Earth
What Are the Different Types of Closed Ecological Systems?
There are different types of closed ecological systems, some of which occur naturally and some that are created by humans. Some of the different types of closed ecological systems include:
- Ecosphere- A closed ecological system for an entire planet is called an ecosphere. For example, the territorial biosphere of the Earth is a unique closed ecological system. This is a natural form of a closed ecological system and not one which is man-made.
- Man-made closed ecological systems- When the term closed ecological systems is used, it usually refers to small, manmade systems that are created to sustain human life. Some examples of these include BIOS-1, BIOS-2, BIOS-3, Biosphere 2, and MELiSSA.
- Aquarium and bottle garden ecospheres- These are two other types of small, man-made closed ecological systems. You can buy them or make them yourself using a closed or partially closed glass container. Things you can include in these types of closed ecological systems include small plants, gravel, shrimp, gorgonia, and algae.
BIOS-1, BIOS-2, and BIOS-3
The Institute of Biophysics in Krasnoyarsk in Russia has spent decades working on creating a closed ecological system. During this process, they created BIOS-1 and BIOS-2. These helped them to develop their current project, BIOS-3. They began to construct this in 1965, and the project was completed by 1972. BIOS-3 is an underground steel structure that is suitable for up to three people and was originally created as a closed ecological system that can support human life. The structure is divided into four compartments, one of which is a crew area that contains three single cabins, a control room, a gallery, and a lavatory.
Another of the compartments was an algal cultivator. The other two compartments, called phytrons, were used to grow wheat or vegetables. Later, the algal cultivator was converted to a third phytron. Each of the four compartments was supplied with light from xenon lamps that gave a level of light comparable to sunlight. To recycle the air breathed by humans, chlorella algae were used to absorb the carbon dioxide and replenish the compartments with oxygen using photosynthesis. The water and nutrients were stores in advance and were recycled throughout the process. By recycling the water, the system’s efficiency had improved by 85 percent by 1968. At that time, urine and feces were not recycled, they were dried and stored. Dried meat was imported into the facility.
Between its creation and 1984, BIOS-3 was used for a variety of tests, including 10 manned closure experiments that included between one and three people in the crew. The longest experiment took place between 1972 and 1973 when a three-man crew participated in an experiment for 180 days. The facility became part of the International Center for Closed Ecosystems in 1991 as part of the subdivision of the Institute of Biophysics at the Siberian Branch of the Russian Academy of Sciences. In 2005, experimentation resumed in collaboration with the European Space Agency, but the focus changed to growing plants and recycling waste.
According to Britannica, Biosphere 2 is a scientific research facility that is designed to emulate the Earth’s environment that is located in Oracle, Arizona. The facility is used for studies into the capacity of humans to build and live in self-sustaining colonies in outer space. The design was first conceived by John P. Allen, an American engineer, in the 1980s. Allen was the director of Space Biospheres Ventures, who purchased the property where the facility is located in 1989, and the construction was complete by 1989.
Biosphere 2 consists of three structures.; an area designated for human habitation, a belowground technology area, and an aboveground airtight glass-enclosed area. The part of the structure that is above the ground is made from sealed glass that is supported by steel frames. Within this structure, there are five ecosystems that replicate different environments on Earth. These include a coastal fog desert, a tropical rainforest, an ocean with a coral reef, savanna grassland, and mangrove wetland. This facility is most famous for its two major experiments that took place in the 1990s. Huffington Post describes one of these experiments. Eight scientists entered Biosphere 2 in 1991 and then lived inside the facility for two years. Four men and four women took part in the project, which aimed to give the scientists the opportunity to learn more about Earth by taking the biosphere on a planetary scale and reducing it in terms of both complexity and size.
Prior to entering the closed ecological system facility, the team of scientists undertook a year of unorthodox training in the Australian outback where they lived with Aborigines. They then entered Biosphere 2 for two years. All the scientists had to work hard during their time in Biosphere 2 as they were effectively managing their own planet. This involved growing their own crops to eat and recycling their air and water.
This project attracted a lot of media attention because the concept of a biosphere was unheard of at that time. Despite a lot of positive interest in the project, there were also some critics of the experiment. Some people described the experiment as New Age drivel and not real science. The scientists were also accused of being part of a cult. Further criticism came following one of the scientists injuring themselves and leaving the facility for treatment before returning.
Living conditions in Biosphere 2 began to deteriorate in 1992 when CO2 levels began to fluctuate wildly, many of the pollinating insects died, and the scientists were forced into a situation where they resorted to eating emergency supplies brought in rather than living off the food they had grown. Despite these problems, the scientists continued with their mission and did not leave Biosphere 2 until September 23, 1993.
Another well-known closed ecological system is the European Space Agency’s MELiSSA project. The aim of this is to create sustainable life support systems for use on the Moon or Mars that are liveable for a longer term than has so far been achieved. This project began in the early 1980s when there was a desire to make exploration of the solar system easier. Secondary to this, the project aimed to resolve some of the challenges faced globally, such as water provision, food production, and waste recycling. There are four main compartments to the MELiSSA ‘Closed Loop’ ecosystem that each requires multiple disciplinary fields of expertise.
The MELiSSA Pilot Plant is based in Barcelona, Spain, and it was inaugurated at the UAB School of Engineering in 2009. The first trial crew consisted of animals, including rats, for safety and cost purposes. In parallel with the MELiSSA loop, there are other ongoing life support technologies in development. One example of this is the grey water treatment unit at Concordia Station in Antarctica. There, they are trying to recreate the closest simulation to space on Earth. Another project is focusing on waste-water technology. This has produced the Biostyr water filtration system. This combines a bioreactor with a physical filter in a closed-loop system that eliminated pollution, such as particle compounds, nitrogenous pollution, and organic pollution. This technology is already in use in 100 towns in the United Kingdom, France, Denmark, and Switzerland.
What Are the Challenges of Creating Closed Ecological Systems?
There are still some challenges that scientists face in creating successful closed ecological systems, says Industry Tap. One of these is accounting for each animal or organism, as their needs are different. For a biosphere to become successful in the long-term, it must take into account these differing needs. Another issue is the collection and monitoring of data during the research. For the projects to become successful in the long-term, researchers must track many key variables, including growth patterns, vapor content, energy levels, and air contents.
However, the main challenge is creating an ecosystem that can sustain life in the longer term. While scientists have enjoyed various levels of short-term success, it is probable that there is still a long way to go before permanent solutions are found for resolving environmental issues or for living in outer space. To do this, scientists need both time and money, both of which are further challenges to achieving success. Large amounts of money are needed to fund these projects as there are huge costs relating to both the technology needed and the human time investment. In terms of time, it is impossible to test whether a system will work in the longer term without testing it over a long period.
Can Closed Ecological Systems Change the Future?
Scientists have come a long way in understanding the Earth’s biosphere and in recreating this using closed ecological systems. Many teams of scientists have enjoyed short-term success in sustaining life using their systems. However, they still face many challenges before it becomes a realistic option to sustain life in the longer term. Despite these challenges, there are signs that some projects have the potential to achieve this in the future, though no time frame has been given as to when this will be possible. If scientists can achieve this longer-term success, then closed ecological systems could provide a solution to both the environmental problems on Earth and the possibility of sustaining life on the Moon or Mars. On the other hand, there are those who believe that it is too late to try and fix climate change, and this is something that scientists may need to face and accept.
Written by Liz Flynn
Read more posts by Liz Flynn