Alastair Westgarth, CEO of Alphabet’s subsidiary Project Loon, published an article “Saying goodbye to Loon” on Medium, announcing the end of Google’s 10-year “Internet balloon”.
The “Google Balloon” is a balloon that is more than 12 feet wide, half filled with helium, and carries a wireless network signal transceiver to form a wireless network. The balloon is released into the stratosphere of the atmosphere, and will float at an altitude between 10km and 20km to provide Internet access services on the ground. If the project is successful, the big balloon can provide wireless network signals to people in remote mountainous areas, and it can also provide wireless network signals in time when the ground wireless network signal is interrupted by an emergency disaster.
Not to mention that the “Internet balloon” project has a long period, faces many problems, and consumes a lot of money. It is a complicated problem to let the big balloon stay in the stratosphere steadily and drift for a long time. However, the project team succeeded. In 2019, the “Internet Balloon” flew more than 40 million kilometers in the stratosphere.
Regrettably, Alastair Westgarth said that the “Internet Balloon” project ended because it could not find a suitable commercialization path. As he said in his blog post, “The road to commercial viability is longer than expected and riskier.”
Coincidentally, after Google launched a large balloon into the stratosphere, scientists at Harvard University plan to launch a balloon this summer. , To test the equipment needed for the first solar geoengineering experiment in the stratosphere.
But compared with Google’s “Big Balloon” project team, the researchers in charge of the experiment at Harvard University hesitate a bit more.
Launch a large balloon into the stratosphere to test the feasibility of the “solar geoengineering” project
In a long glass tube in a laboratory at Harvard University, there is a miniature model that mimics the stratosphere. The glass tube is wrapped in gray insulating material. By filling the glass tube with suitable gas at a specific temperature and pressure, it is possible to simulate the environment of the stratosphere about 20 kilometers away from the earth’s surface.
The research team tested the reaction of various chemical substances in this thin air, hoping to conduct a rough test on a controversial scheme, which is the “solar geoengineering” project.
The plan responds to climate change by spraying tiny particles into the stratosphere to reflect more solar heat back into space. How to spray tiny particles into the stratosphere? Like Google, a large balloon is launched into the stratosphere of the atmosphere, which carries the tiny particles planned to be sprayed.
So here comes the question: Can glass tubes mimic “what the stratosphere really looks like?” Even Keutsch, the director of the “Solar Geoengineering” project and professor of engineering, chemistry and atmospheric sciences at Harvard University, also questioned this. In fact, this is the disadvantage of simulation experiments. Even if scientists try to consider all conditions, all possible problems, and all possibilities, the simulation device cannot be the same as the real stratosphere.
If the simulation test of the glass tube is far from the real atmospheric stratosphere, it means that the possibility of the “solar geoengineering” program can be implemented is very small. For this reason, the research team hopes to transfer the experiment from the simulation device to the real stratosphere. They hope to perform a series of balloon missions for related experiments, the first of which will be launched this summer from the Esrange Space Center in Kiruna, Sweden.
The first flight only assesses whether the aircraft’s equipment and software can work normally in the stratosphere. In the stratosphere, the temperature may drop below 50 degrees Celsius, and the pressure range is one-tenth to one-thousandth of sea level. In the subsequent launch, the researchers hope to release a small amount of particles that may scatter sunlight, and by dispersing particles in the atmosphere to weaken the light, and offset some of the climate warming caused by greenhouse gas emissions to cool the earth.
Inspired by a volcanic eruption, voices of opposition came
Large-scale release of particles may mean messing up the Earth’s weather patterns, and the effect is unpredictable. In some places, they may even cause catastrophic changes. So what are the scientific principles behind this bold plan that is almost science fiction? In other words, does it have any experience to refer to?
Harvard University Professor Frank Keutsch, Principal Investigator of SCoPEx
In 1991, the main volcano of Mount Pinatubo erupted and emitted millions of tons of sulfur dioxide. In the following years, the global temperature was also suppressed. Studies have shown that the sulfur dioxide emitted by coal-fired power plants and ships can also achieve a measurable cooling effect. The factual basis for the “Solar Geoengineering” program also comes from this.
But critics believe that it is reckless to deliberately use it as a measure to combat climate change and should not even be considered, let alone an experiment.
Studies have found that solar geoengineering can significantly change rainfall patterns and locally reduce the yield of certain crops. On the other hand, other papers have concluded that as long as solar geoengineering is carried out in an appropriate manner, the negative impact on the environment will be small.
But so far, with a few exceptions, all studies have been conducted in computer models or laboratories. So Keutsch believes that its balloon test will be critical.
Balloon with propeller and sensor
The basic idea of the SCoPEx experiment was proposed as early as 2014, which is to launch a balloon equipped with propellers and sensors to release two kilograms of submicron particles in a plume of about one kilometer long. Keith points out that this is equivalent to the number of particles produced per minute by a commercial airliner.
Then, the balloon will turn and slowly zigzag through the plume from the opposite direction. The sensor on the balloon will measure the dispersion range of the particles, observe how the particles interact with other compounds, and the sunlight that can be reflected.
All test results can be fed back into the computer model, thus deepening researchers’ understanding of the effect of spraying hundreds of thousands to millions of tons of particles
At this point, the team hopes to conduct a series of flights in the next few years. Initially, they intended to release a dust of calcium carbonate (the main component of chalk), but eventually the researchers wanted to test other materials, including sulfuric acid (a by-product of sulfur dioxide released by volcanic eruptions).
However, some people worry that even for limited experiments, they have done a little too far. Wil Burns, co-director of the Institute of Carbon Removal Law and Policy at American University, believes that before conducting outdoor experiments, one should try to reach a global consensus on whether society can use this tool. But for him, the answer is no: the environmental impact of the experiment is not yet known. And the challenge of governing this tool is huge. A country can carry out solar geoengineering on its own, but all other countries will be affected. And future generations may be forced to deal with the impact for hundreds of years. He added that until it is fully deployed, we will not know its true role on a global scale. In a sense, we will fall into drought or other dangers until the impact subsides.
Swedish government officials will conduct the first SCoPEx flight in the country and will be managed by the head of the Swedish Aerospace Corporation. Some environmental groups and solar geoengineering critics have called on Swedish government officials to stop the experiment. They believe that the research itself does not bring environmental risks, but it creates “the road to standardized deployment” for dangerous and powerful tools.
The Swedish Greenpeace Biofuel Observatory and other organizations wrote a letter stating that solar geoengineering technology “is a technology that may bring extreme consequences, and is dangerous, unpredictable and unmanageable. There is no reasonable reason to come. Test dangerous technologies that have never been used.”
The expert in question: I am more worried about the negative consequences that may be brought about after the test is successful
In the face of concerns and criticisms from the outside world, Keutsch, a researcher of the project, agreed, and he also expressed his views.
Keutsch believes that solar geoengineering is the wrong way to solve climate change. He likened it to opioids. Although it can relieve severe pain, it can lead to other problems such as addiction. A safer and more effective solution is to quickly reduce greenhouse gas emissions.
Keutsch’s worries are not limited to the success or failure of the test, he is more worried about the possible undesirable consequences after the test is successful. As the project leader, he believes that solar geoengineering experiments may make the ultimate application of this technology more likely.
If his conjecture is correct, he is worried that climate change has been so long, and it is likely to become more destructive. Some desperate countries may continue to advance solar geoengineering. An earlier study by Harvard University found that the annual cost of developing and launching a set of aircraft to complete this task is only $2 billion, which is affordable by many countries.
Then, the technology obtained in this experiment may be the only tool that can truly change the global temperature during a certain leader’s political tenure. It may become an attractive choice for countries suffering from deadly heat waves, droughts, famines, fires or floods.
Therefore, Keutsch said: “It will be’very dangerous’ to use without sufficient research. It is a very scary concept and will go wrong. But at the same time, I think I have a better understanding of what may exist Risk is very important. If there is a material that can significantly reduce risk, I think we should understand it.”
The consequences of the test are unknown
The Keutsch research team has performed computer simulations, such as exploring how particles released from the device dissipate into the air. If they do start testing, they should be able to more accurately measure how particles of calcium carbonate or sulfuric acid are dispersed or gathered together. This is a key test of how much these substances play in solar geoengineering. If the particles are too large, they will quickly sink from the stratosphere, and the research team will need more matter to scatter the same amount of sunlight.
Another key question is how these particles react with other chemicals in the stratosphere-especially calcium carbonate, because this reaction does not occur naturally in the stratosphere.
In the end, the team chose calcium carbonate as the test particle. As Keutsch said: “Sulphates can swallow the protective ozone layer, and although they have a cooling effect on the earth’s surface, they warm the stratosphere. This may cause changes in the weather in unpredictable ways, and our model cannot be very It’s good to predict this way of interfering with the earth system.”
But Keutsch added: “Calcium carbonate also has its own unknowns. Those experiments conducted in glass tubes found that it has no particular reactivity with compounds encountered in the stratosphere. But the way it interacts with other chemicals may It will affect the observations during the mission, which can help us to further understand the number of these particles required to reduce the global temperature, and the possible risks or effects of releasing these particles.” In a
nutshell, the researchers started from small What the balloon experiment has learned is still very limited. Because the particles are too thin, they will not be able to detect the long-term fate of the particles released into the stratosphere. Therefore, Keutsch also admitted that before large-scale deployment of solar geoengineering, some things are unknown.
To resolve global climate issues, supervision and review are necessary
In fact, the team initially hoped to start a balloon flight in Tucson, Arizona as early as 2018, and then explore follow-up plans in New Mexico. According to the project website, they chose to transfer the first batch of work to Sweden due to “new crown pneumonia, logistics and scheduling challenges.”
Part of the reason for the delay of the experiment was because the Keutsch team decided to establish an independent committee to evaluate the ethical and legal impact of their proposed experiment. They don’t have to set up a committee, because there is no federal funding for this research. In fact, when this project started, the US federal government did not fund solar geoengineering research. The project relies on internal funds from Harvard University and donations from individuals and groups such as the Bill Gates, William and Flora Hewlett Foundation, and the Alfred P Sloan Foundation.
But Jane Long, the former deputy director of Lawrence Livermore National Laboratory, strongly recommended the establishment of an external review committee. She also helped select the chairperson of the committee. She said: “Don’t let people think that they are doing experiments without review. Scientists, this is very important to the future of this technology.”
Long emphasized that, as initially proposed, these experiments are very small and unlikely to cause harm to health or the environment. But she said the committee can force researchers to clarify the purpose of the work and address public concerns.
The independent committee has issued a report that recommends how the research team should communicate with the public before releasing the particles. Among other things, the independent committee also recommended the creation of a briefing manual to explain these issues, and invites people living near the balloon flight route to “participate in consultations about the experiment itself and the management of solar geoengineering research.”
However, Burns and others in the previous article believe that the committee lacks some key voices, namely critics of solar geoengineering research and representatives from poorer countries. He believes that these blind spots are obvious in the committee’s preliminary report: “It assumes that we are only conducting simple public participation to figure out how to enter the next stage in the field experiment, and there seems to be a foregone conclusion: What will happen and what should happen.”
In the next few weeks, an independent advisory committee is expected to review the legal, ethical, and environmental issues of the project and determine whether the research team should conduct its first flight. It is also reported that the committee must also make a ruling before the actual flight of the released particles and determine what steps the research team should take or must take to contact the public and regulatory agencies. If these launch missions are approved, it will be the first solar-powered geoengineering experiment in the stratosphere.
Finally, regarding the feasibility of the solar energy project, I interviewed Tong Dan, a postdoctoral researcher at the University of California, Irvine, who is about to join the Department of Earth Science Systems at Tsinghua University. She currently believes that the plan is very low.
She said: “The potential hazards are unknown, such as for other extreme climates, such as extreme temperatures and rainfall. The theoretical basis and experiments are insufficient, and the implementation of this project will have regional differences, so its complexity and difficulty Sex will be more than we thought.” What about the
follow-up of the “Solar Geoengineering” project? Whether the research team can successfully launch large balloons into the stratosphere of the atmosphere, we look forward to good news.