Why Geoengineering is a False Solution to the Climate Crisis

Published October 15, 2024

By Mary Church, Geoengineering Campaign Manager at the Center for International Environmental Law, and Rossella Recupero, Communications Campaign Specialist at the Center for International Environmental Law


This is the first in a multi-part series exposing the threats and risks connected to geoengineering and why these technologies must not be considered effective climate action.


As global temperature records continue to be broken month after month and extreme weather events increase in severity as a result of climate change, governments and companies worldwide are increasingly investing in and exploring climate geoengineering as a supposed “solution” to global warming.

Once dismissed as science fiction, geoengineering has started to enter mainstream climate discourse. Despite being at odds with international law and subject to a de facto global moratorium, an alarming number of geoengineering field experiments are planned or underway, many driven by voluntary carbon markets.  

Behind the shiny facade of these highly speculative  “techno-fixes,” geoengineering is fraught with risks, uncertainties, and dangers that threaten to delay real climate action and cause more harm than good. 

What Is Geoengineering?

Geoengineering refers to large or planetary-scale interventions in the Earth’s atmosphere, oceans, and land to counteract some of the effects of climate change. These methods range from reflecting sunlight to removing carbon dioxide from the atmosphere. 

Crucially, none tackle the root causes of the climate crisis, the primary driver of which is the production and burning of fossil fuels.

Geoengineering Categories

Solar Radiation Modification Or Manipulation (SRM)

 SRM techniques attempt to reflect sunlight back into space to cool Earth. Methods include releasing large amounts of tiny reflective particles (e.g., sulfur dioxide) into the stratosphere, deploying mirrors in space, or modifying clouds, ice, and plants to make them more reflective.

Carbon Dioxide Removal (CDR)

CDR techniques theorize removing carbon from the atmosphere on a massive scale. Methods range from sucking carbon straight out of the air to the large-scale burning of trees for energy, capturing and storing the emissions, and even dumping minerals in the ocean or developing monoculture seaweed mega-farms to increase carbon uptake.

Other approaches

Other theories include slowing ice melt by pumping seawater onto polar and glacial ice to thicken it, spreading billions of tiny reflective beads on the surface of the Arctic or glacial ice to increase its reflectivity, and building a giant curtain in the ocean to block warmer waters. 

Why is Geoengineering a Bad Idea?

  1. It won’t fix the climate crisis

Geoengineering technologies do nothing to address the drivers of the climate crisis, and all come with major risks and unknowns. For example, solar geoengineering is inherently unpredictable and risks further destabilizing an already destabilized climate system. Models show that it would have an uneven effect regionally and could exacerbate climate change in countries on the front line of the crisis. What’s more, it carries the risk of ‘termination shock’ where temperatures suddenly spiral if, for whatever reason, deployment is paused or stopped. Meanwhile, no marine carbon dioxide removal techniques have been proven effective in the long-term removal and storage of CO2, and some could undermine the ocean’s ability to sequester carbon. 

  1. It’s a dangerous distraction that undermines real climate solutions 

The illusion that geoengineering can help “fix” climate change is a dangerous distraction from the real solutions to the crisis and risks prolonging fossil fuel dependence. In fact, geoengineering technologies are inherently unpredictable and pose new, significant, unprecedented risks to the fragile ecosystems that sustain life on Earth, which are our best allies in the fight against the crisis. What’s more, relying on the promise of future speculative technologies instead of implementing real solutions today will lead to an overshoot of the critical climate threshold of 1.5ºC and lock in catastrophic climate change. By undermining transformative, justice-centered solutions to the climate crisis, geoengineering approaches also risk entrenching inequitable political and social power and perpetuating neocolonialism

  1. It would turn Earth into a risky lab

By their very nature, it’s impossible to test geoengineering technologies for their intended impact on the climate without large-scale outdoor deployment, by which time any harmful and potentially irreversible impacts would be locked in. Research showing theoretical benefits tends to use highly idealized models underplaying harmful impacts and the likelihood that deployment would not go as planned in the real world. Small-scale outdoor experiments only serve to help develop technology and risk a slippery slope to deployment.  

  1. It requires an unprecedented scale for any meaningful climate impact

To have any chance of their intended impact on the climate geoengineering technologies would have to be deployed at a truly unprecedented scale – with enormous political, social, and environmental consequences. For example, ocean fertilization and ocean alkalinity enhancement would require approximately 10 percent of the ocean’s surface for a meaningful climate impact. While for SRM to have its intended effect, the Earth would be locked into using these risky technologies for an indeterminate amount of time while emissions were reduced by highly speculative CDR approaches, with so-called “peak-shaving” scenarios for stratospheric aerosol injection implying deployment of 100- 200 years.

  1. It risks  undermining human rights of billions

The United Nations Human Rights Council’s Advisory Committee has warned that geoengineering technologies “could seriously interfere with the enjoyment of human rights for millions and perhaps billions of people” – because of the intended scale of deployment and the inherent risks involved. It has also drawn attention to the disproportionate impact on those who have done the least to cause the climate crisis, including communities in the global South, Indigenous Peoples, peasants, and fisherfolk. 

  1. It’s at odds with international law

Geoengineering has been restricted by a de facto moratorium under the Convention on Biological Diversity since 2010. States Parties to the London Convention / London Protocol, which regulates pollution at sea, are considering expanding its 2008 prohibition on ocean fertilization to include four additional categories of marine geoengineering techniques. The development and deployment of geoengineering technologies are also potentially inconsistent with a wide range of legal obligations and principles under international law.

  1. It would be impossible to govern deployment fairly or safely 

Because of the proposed scale and duration of geoengineering, and the inherent risks it poses, there is nothing in human history to suggest that deployment could ever be fairly or safely governed. For example, Stratospheric Aerosol Injection is likely to require constant injection of sulfur compounds in the upper stratosphere over multiple generations if not centuries – a feat that only powerful nation-states or military regimes would be able to attempt. What’s more, the uneven impact of any cooling would create  ‘winners and losers’, exacerbating geo-political tensions, and the risk of termination shock from any pause or cessation.

What Should Policymakers Do?

Geoengineering is neither insurance to “buy time” nor any form of supplement to mitigation. Instead of chasing fantasy techno-fixes, governments should urgently prioritize real solutions to the climate crisis. This means equitably phasing out fossil fuels and supporting the many decentralized, diverse, and readily available alternatives for socially and ecologically sustainable production and consumption patterns. 

It requires wealthy countries to step up to their responsibility for causing the climate crisis and  provide climate finance in accordance with their fair shares, to enable countries on the frontlines who have done least to cause the problem to cut emissions, adapt to climate impacts, and eradicate poverty . 

It also means protecting and restoring the forests, oceans, and polar and other ecosystems that are our best allies in the fight against climate change, while upholding the rights of Indigenous Peoples who are in direct relationship with these ecosystems, and the communities who depend on them for their livelihoods.