Over the Northern Hemisphere's summer, the world's temperatures hovered near 1.5° C above pre-industrial temperatures, and the catastrophic weather events that ensued provided a preview of what might be expected to be the new normal before mid-century. And the warming won't stop there; our current emissions trajectory is such that we will double that temperature increase by the time the century is out and continue beyond its end.
This frightening trajectory and its results have led many people to argue that some form of geoengineering is necessary. If we know the effects of that much warming will be catastrophic, why not try canceling some of it out? Unfortunately, the list of "why nots" includes the fact that we don't know how well some of these techniques work or fully understand their unintended consequences. This means more research is required before we put them into practice.
But how do we do that research if there's the risk of unintended consequences? To help guide the process, the American Geophysical Union (AGU) has just released guidelines for ensuring that geoengineering research is conducted ethically.
Geoengineering basics
Geoengineering involves an intentional intervention meant to change the state of the climate system, and so is a contrast to the unintentional climate change we've driven via our fossil fuel emissions. It breaks down into two general categories: solar radiation management, which is meant to limit the energy we receive from the Sun, and carbon dioxide removal, which seeks to reverse some of the rise in greenhouse gases our use of fossil fuels has produced.
The former can potentially block some of the sunlight in space that would otherwise reach us. But this intervention is more likely to involve reflecting some incoming sunlight back out of the atmosphere, either by enhancing clouds or putting reflective aerosols into the stratosphere. Referring to this approach, the National Academies of Science noted, "Scientific understanding of many aspects of solar geoengineering technologies remains limited, including how they could affect weather extremes, agriculture, natural ecosystems, or human health."
Carbon dioxide removal would seem to be simpler in that it's seemingly reversing the process that got us in trouble in the first place. But we're not going to be able to convert the carbon dioxide to coal and bury it back in former mines. Instead, we've got many ways of storing it: reforestation, pumping it into underground storage formations, reacting it with different types of rocks, storage through ocean chemistry, and so on. Depending on the method and extent of storage, these could have various potential implications.
Critically, any of these methods are relatively inexpensive, raising the risk that a single country or even a wealthy individual could start pursuing them in the near future. Indeed, in 2022, a startup promised it would start offering solar radiation management as a service to offset emissions—and, sadly, two years later, it's still an ongoing concern.
This adds to the urgency of our need to understand the potential consequences of these activities. But research in the area is fraught with some of the same worries that actual geoengineering causes. And there's the added concern that successful geoengineering will be leveraged as a way to continue our carbon emissions rather than correcting for past emissions. This is why the AGU put together a group of stakeholders to come up with ethical guidelines.
Keeping things ethical
The AGU emphasizes two things. One is that, even if we gain a good understanding of the risks and benefits of a geoengineering technique, it should always be a secondary priority compared to limiting our carbon emissions. The second is that the guidelines it has created are indebted to the efforts of a variety of people and organizations that have drawn up previous documents meant to help guide this sort of research. The AGU's approach is organized around five principles:
Responsible research: Again, the guidelines emphasize that "the pursuit of climate intervention research should not be presented as a replacement or alternative to emissions reduction." It defines responsible research as focused on an assessment of risks in order for the public and policymakers to balance them against the potential rewards derived from limiting warming (and, in the case of carbon dioxide removal, avoidance of ocean acidification). And the public should be given a clear picture of how any research will contribute to our understanding of these benefits and harms before the research begins.
Holistic climate justice: The guidelines recognize that geoengineering won't affect just those people currently residing on Earth, but future generations as well. Some methods, like stratospheric aerosols, don't eliminate the risks caused by warming but shift them onto future generations, who will face sudden and potentially dramatic warming if the geoengineering is ever stopped. Others may cause regional differences in either benefits or warming, shifting consequences to different populations.
Special attention should be paid to those who have historically been on the wrong side of environmental problems in the past. And harms to nature need to be considered as well.
Inclusive public participation: The research shouldn't be approached as simply a scientific process; instead, any affected communities should be included in the process, and informed consent should be obtained from them. There should be ongoing public engagement with those communities and the process should adapt to their cultural values.
Transparency: The public needs to be aware of who's funding any geoengineering research and ensure that whoever's providing the money doesn't influence decisions regarding the design of the research. Those decisions, and the considerations behind them, should also be made clear to the public.
Informed governance: Any experiments have to conform to laws ranging from local to international. Any research programs should be approved by an independent body before any work starts. All the parties involved—and this could include the funders, the institutions, and outside contractors—should be held accountable to governments, public institutions, and those who will potentially be impacted by the work.
If you think this will make pursuing this research considerably more complicated, you are absolutely correct. But again, even tests of these approaches could have serious environmental consequences. And many of these things represent best practices for any research with potential public consequences; the fact that they haven't always been pursued is not an excuse to continue to avoid doing them.
