Researcher in Geoengineering: A Worst-Case Scenario Has Now Become a Reality

Particles released into the atmosphere to block the sun's rays and crushed rock in fields that absorb CO2 are examples of geoengineering. Geoengineering attempts to intervene in climate or environmental systems with technical solutions to slow down global warming and reduce the consequences of climate change. Assistant Professor at the Department of Business Development and Technology, Chad M. Baum, investigates how people understand and perceive technologies related to geoengineering. For him, 2025 has presented a worst-case scenario for the uncontrolled development of certain technologies, but he has also found hope and optimism in his collaboration with researchers in the Global South.

What are your current interests?

“I work on some large EU projects through GENIE, which stands for Geoengineering and Negative Emissions in Europe. We work broadly with European studies of public perceptions of geoengineering technologies. Overall, it’s about technologies that deliberately intervene in the climate system to mitigate or prevent climate change. There are two main categories. One is solar geoengineering. Basically, it's about influencing how much sunlight reaches the Earth's surface. For example, it could be stratospheric aerosol injection, where particles are released high in the atmosphere that reflect some of the sunlight into space. 

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The second main category is Carbon Dioxide Removal (CDR). These are technologies that aim to capture and store CO2 from the atmosphere. In GENIE, we have conducted questionnaire surveys in 30 countries and focus groups in 22 countries to investigate how people perceive these technologies. Now we want to get closer to local experiences. We have received funding for a project where we work with farmers and rural areas in Denmark on CO2 removal through improved weathering of rocks. It’s a method of CO2 removal that takes advantage of the fact that certain types of rock absorb CO2 when they weather. Normally, it takes thousands of years, but by crushing the rocks and spreading them on agricultural land, the process can be accelerated. It can both reduce CO2 and release minerals that can replace fertiliser. We hold workshops across Jutland, but it’s especially relevant in countries where fertiliser is expensive. We have also been in contact with farmers in Ghana, and we’re in the process of developing partnerships with developers working in other countries, such as India.”

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What is the most remarkable thing that has happened within your field in 2025?

“Every year there are intense discussions about how, among other things, solar geoengineering technologies should be regulated. There is still no effective global governance model, which divides researchers. Some argue that the technologies should be banned entirely, while others believe that we should be prepared, either because they might become necessary or because a state or private actor might choose to act on its own. 

Some argue that the technologies should be banned entirely, while others believe that we should be prepared, either because they might become necessary or because a state or private actor might choose to act on its own

The biggest thing that has happened in the past year is that an American-Israeli startup has its own plans for stratospheric aerosol injection, where they send particles into the atmosphere that will reflect some of the sunlight back into space. The company is even looking to patent the particles they are developing. this news was received almost unanimously negatively among researchers. Even those who are more positive about solar geoengineering emphasise the importance of it being done in a fully public, transparent way, and without patents being in the picture. The company in question has opted to take the completely opposite approach and has been working in secret until recently. What was previously considered a worst-case scenario has now become reality.”

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What worries you most as you look ahead to 2026?

“That we risk precisely this worst-case scenario: private companies, driven by investor interests, carrying out unapproved tests. Another concern is that the focus on these technologies may reduce the willingness to reduce emissions. This is called moral hazard or mitigation deterrence (when promises of future solutions reduce the willingness to take current steps to reduce emissions, ed.). It hasn’t yet happened on a large scale, but early signs can be seen, for example, among American Republicans. At the same time, we see that people are starting to blame technologies that manipulate the weather for severe weather phenomena. It can trigger conspiracy thinking because it touches on something very fundamental in our relationship to living and to our world. Sunlight is central to life on Earth. It creates an instinctive fear when you talk about blocking the sun's rays, and this can make it difficult to have a nuanced debate.”

What gives you hope and optimism?

“First of all, there seems to be in general greater openness in the Global South to learning about and discussing these solutions. They are more directly affected by climate change and want to be involved. I work with the Degrees Initiative, which supports researchers in the Global South so they can contribute to the debate. It gives hope to bring in more voices and avoid blind spots from a narrow Global North perspective. Even in Denmark, I see hope—for example, in developments surrounding the new CO2 tax on agriculture. An important transition is coming, and we will explore how farmers can use new technologies and help reduce emissions while still being able to thrive. Giving them a voice is crucial.”

This article is machine translated and post-edited by Lisa Enevoldsen.