Reflecting on — and for — our Future
A conversation with Astera Resident Dakota Gruener on uncovering answers and driving action on how we can address our rapidly warming climate
When Dakota Gruener first began her career in global health policy, she was driven by a simple but powerful question: what are the biggest levers we can pull to improve human wellbeing? In pursuing that question, she’s traveled across continents and disciplines, from vaccine access in Cameroon to digital identity systems in Bangladesh. After a stark revelation about climate displacement, she’s now taking on one of the most complex and controversial frontiers in climate science: sunlight reflection.
Today, as a Resident at the Astera Institute, Dakota leads Reflective, a research organization focused on evaluating the science, risks, and governance of methods that could reflect sunlight away from Earth and potentially cool the planet. We sat down with her to explore her approach, why sunlight reflection demands urgent research, and what it means to pursue climate solutions that could prove essential, even when they come with a great deal of unknowns.
Your career path has been quite unique. How did you journey from global health policy to climate science?
When I started my career in global health policy, I was driven by a fundamental question: what are the biggest levers we can pull to improve human livelihoods? This first led me to vaccine policy and working with organizations like GAVI, the Vaccine Alliance.
During a trip to Cameroon for the launch of their rotavirus vaccination program, I had a moment of clarity that would eventually reshape my career. I discovered that the district was reporting 140% vaccine coverage. What does it even mean for 140% of the population to be vaccinated? After asking questions, I learned they had accurate records of vaccines delivered, but the population data — the denominator — was based on census information from the 1980s.
This revelation sparked an obsession with vital registration statistics. Without knowing who you're trying to serve, how can you provide services effectively? This path eventually led me to build and lead ID2020 for six years, working on privacy-protecting digital identity solutions.
The second pivotal moment came in 2018 when we were working with the Government of Bangladesh. Behind closed doors, they shared that they were prioritizing identification systems that would work beyond their borders because they anticipated a significant portion of their population could be displaced due to climate warming in the not-too-distant future.
That was my awakening to climate change as an existential threat. I realized we don't have the absorptive capacity for hundreds of millions of displaced people. I felt like I couldn't not work on this issue – it was clearly the most important challenge of our time.
What drew you to sunlight reflection methods in particular?
I quickly recognized that we need to be doing everything we can to decarbonize, but I couldn't see how I personally could change the trajectory of decarbonization efforts. And regardless of how quickly we move, it's not going to be fast enough to prevent substantial suffering.
This realization led me to other methods we need to research. Sunlight reflection, also called solar radiation management (SRM), is an emerging field of research into interventions that increase the amount of solar energy reflected back into space, avoiding warming and its global impacts. SRM may be the only real lever we have to cool the planet quickly enough to prevent catastrophic impacts on people and ecosystems while we work on more permanent solutions — dramatic emissions reductions, adaptation, and rapid scaling of carbon removal.
The critical thing is: we don't know if it's a good idea or not. We don't have the data. But if we don't research it now, we won't have the knowledge we need when the time comes. And as time passes, the likelihood that some nation will deploy SRM without adequate understanding only increases.
We're in a race to understand the different potential pathways to cool the planet. What risks are associated with each approach? How can we evaluate their safety and efficacy?
Can you explain some of the basic science behind sunlight reflection methods?
At its simplest, climate warming is dictated by a basic energy balance. Energy comes in from the sun, warms the Earth's surface, and is re-emitted as infrared energy. Some of this energy leaves the Earth’s atmosphere, but some of it gets trapped and reflected back to Earth by greenhouse gases in the atmosphere.
As we increase the amount of greenhouse gas, the energy balance is disrupted — more energy stays trapped in our atmosphere. So it’s critical to reduce the amount of greenhouse gas, but it’s only one part of the equation. SRM addresses the other side of this energy balance, by reflecting some of the incoming sunlight back to space before it ever reaches Earth.
Stratospheric aerosol injection, which is the approach we focus on at Reflective, is currently the best-known and potentially the only feasible approach to meaningfully cool the planet. The premise is based on a natural phenomena: when volcanoes erupt, they emit gases and aerosols into the atmosphere that diffuse and reflect sunlight, causing temporary drops in global temperatures.
For example, the Pinatubo eruption in 1991 lofted about 15 million tons of sulfur dioxide into the lower stratosphere, and over the next 15 months, global temperatures dropped about half a degree Celsius. The idea behind stratospheric aerosol injection is to do this intentionally to limit warming.
There are other approaches like marine cloud brightening, which aims to make low-lying clouds more reflective by reducing the water droplet size. While this shows promise for localized cooling – for instance, researchers in Australia are exploring it to help save the Great Barrier Reef – it doesn't appear feasible for global cooling due to the enormous scale and infrastructure it would require.
How do you approach the ethics and governance challenges of researching technologies that could affect the entire planet?
If stratospheric aerosol injection were deployed, it would have global consequences – there's no way to do regional deployment only. For some people, this governance challenge seems so insurmountable that they consider it a non-starter.
My response draws from my multidisciplinary background. We can learn from the history of how other complex technologies have been debated and deployed — new medical therapeutics, GMOs, gene drives. These are all complicated issues that required careful governance frameworks, and none were purely questions of science or technology.
I think about this a lot like clinical trials in medicine, which provide a pathway and framework for carefully sequencing research and defining stage gates. You run a finite, specific experiment with clear criteria. If those criteria are met, you can consider proceeding to the next phase. If not, you cannot proceed. This addresses the "slippery slope" concern that many have — that once research begins, deployment becomes inevitable.
Ultimately, any decision about deployment will involve some uncertainty. But right now, there's too much uncertainty. We know some things with confidence: aerosols in the stratosphere cool the planet; they can do so quickly and relatively evenly; and the process has built-in reversibility — if you stop, the effects fade as the aerosols naturally leave the atmosphere.
But there are still significant unknowns around aerosol microphysics, ozone depletion, and the translation of climate model outputs into impacts that matter for policymakers in specific regions. These are the questions our research aims to address.
Sticking with the clinical trials analogy — in this context, there’s no equivalent of a regulatory body like the FDA. What does that mean for transparency and trust for Reflective?
You're right that we don't have an equivalent to the FDA — there isn't a regulatory body at either the national or international level for this type of research. This places a burden on the research community to operate with exceptional transparency.
At Reflective, we're trying to hold ourselves to the highest possible standards. Our climate simulator is fully open source with detailed methodology explanations. All our funders are named on our website — we won't accept anonymous funding or funding from anyone with ties to oil and gas.
We also publish our scientific prioritization process, explaining what we consider the most consequential sources of uncertainty, how large those uncertainties are, and why we're funding the research we're funding.
This transparency isn't performative. It's essential for building the trust needed in a field that many people find unsettling. Without trust, we can't have the necessary conversations about whether and how to move forward with this research.
How do you respond to concerns that researching sunlight reflection might create a "moral hazard" by reducing the urgency of emissions reduction?
This is a common concern, but I think it's important to unpack the different reasons people oppose this research. The moral hazard argument suggests that if people think there's a technological fix for climate change, they'll stop working on emissions reductions.
However, we haven't seen evidence of this. If anything, when people learn about extreme measures like stratospheric aerosol injection being considered, it often forces them to confront just how bad the climate crisis could become, which can actually increase their support for decarbonization.
I care deeply about people's wellbeing. If someone suggests they're willing to let more people die or suffer to maintain the narrative that emissions reduction is the only answer, that reflects a different moral code than I follow. I want people to be okay, and that means pursuing all possible avenues to prevent catastrophic warming.
We need both rapid decarbonization and research into potential emergency measures. It's not an either-or situation.
What does success look like for Reflective as an organization?
Our primary goal is to bring clarity to the research roadmap — identifying the questions that most need to be answered and the timelines and dependencies associated with those questions.
This field has historically been underfunded and research has been relatively ad hoc and curiosity-driven. We don't have time for a meandering approach. By defining a rigorous research roadmap, we aim to guide not only our work but also help other scientists and funders prioritize their efforts.
We track our progress by systematically retiring uncertainties from that roadmap. Any question that gets resolved — whether by us or others — represents a win for the field.
Our work has three main pillars: developing the research roadmap, funding or conducting research to address key questions on that roadmap, and building infrastructure that researchers and policymakers need to engage with this topic effectively.
On the infrastructure side, we're launching a cloud hub with pre-processed data and computing resources so researchers worldwide can more easily work with the enormous datasets involved. We're also developing tools like our climate simulator that allow non-technical audiences to understand potential impacts at both global and regional levels.
How do you personally envision the role of sunlight reflection methods in our climate response over the next 5-10 years?
I believe researching SRM is critically important. We absolutely need more mitigation, adaptation, and carbon removal, but we also need to understand if sunlight reflection methods could help prevent catastrophic suffering.
I'm fundamentally driven by a desire to see as many people thrive as possible. Borrowing a line from the Gates Foundation, someone once described my approach as being an "impatient optimist." That feels accurate. This research is incredibly important, either to prevent significant suffering, or perhaps even to improve human flourishing.
Given what's at stake, I feel an urgency to understand whether stratospheric aerosol injection is a good idea or not. The humanitarian cost of not having this option if we need it could be enormous.
Dakota is a resident at Astera Institute, bringing expertise in climate intervention research and policy. Through Reflective, Dakota is working to advance our understanding of sunlight reflection methods and build the frameworks needed for responsible decision-making about these technologies.
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Great interview and it is good to read about the important work Reflective is doing. As controversial as this type of geoengineering is in some circles, dismissing it without even bothering to collect data first is the real threat. The fact of the matter is that we are up against the wall and failing to respond. As someone who specialized in nature-based solutions, this type of technology is the opposite of what I think we should be doing, but since we're collectively lagging in all kinds of responses I recognize that we may come to desperately need solutions like SRM. Ultimately we need the ability to respond to the climate crisis with agility and in as many ways as possible.