Geoengineering 101
Geoengineering 101
What is geoengineering?
Geoengineering includes many different technologies. They are all risky, speculative and poised to grow the power of wealthy elites and corporations. None address the root causes of climate change.
Solar radiation manipulation (SRM)
Carbon dioxide removal (CDR)
Marine Geoengineering
The worlds ocean’s are increasingly being targeted for geoengineering technologies, including deliberate creation of enrormous algal blooms (Ocean Fertilisation), dumping of minerals (Ocean Alkalinity Enhancement), and spraying seawater to ‘brighten’ clouds (Marine Cloud Brightening).
Land-based geoengineering
Land-based geoengineering includes technologies such as Bio-Energy Carbon Capture and Storage (BECCS), Biochar and Direct Air Capture (DAC) which all require massive areas of land and entail enormous threats to the environment, land and human rights. Other land-based SRM technologies include covering Arctic or glacial ice with reflective glass.
Atmosphere and space geoengineering
Some of the most controversial geoengineering technologies include spewing massive amounts of particles (Stratospheric Aerosol Injection) into the stratosphere to dim the sun. Some even propose placing huge numbers of mirrors in space.
Solar Radiation Modification would impact global and regional climate and weather systems at their core, with consequences that could simultaneously trigger devastating impacts across several continents. For any meaningful effect on the climate, deployment would have to be at large regional or planetary scale. Modelling has suggested that Stratospheric Aerosol Injection could for example unsettle the Indian monsoon and exacerbate droughts in large parts of Africa with devastating consequences for millions or even billions of people. What’s more, harmful impacts are likely to be experienced far from the place of deployment.
For Carbon Dioxide Removal technologies such as Bio-Energy Carbon Capture and Storage (BECCS), Direct Air Capture (DAC), Ocean Fertilisation or Ocean Alkalinity Enhancement to have any theoretical impact on the global average temperature their scale would need to be enormous. Geoengineering-scale CDR would unavoidably cause severe disruptions to ecosystems. Some climate models have assumed creation of BECCS plantations as large as a third of the entire landmass of Africa. In fact, the global land gap report estimates that 1.2 billion hectares of land would be required to effectively fulfil governments’ pledges for all land-based CDR techniques. Several marine geoengineering techniques envisage utilising 10% of the ocean’s surface, and risk undermining the oceans fragile equilibrium and compromising existing carbon storage.
What are risks and possible impacts of geoengineering?
As people are starting to realise that society can and must decarbonize to real zero emissions as quickly as possible, and that we already have the technologies to do so, geoengineering provides fossil fuel and other polluting industries with yet another excuse to delay taking the action required. This may cause us to miss the opportunity we have for genuine and timely societal transformation.
All forms of geoengineering would have direct harmful impacts on both communities and ecosystems. Their very scale makes them inherently problematic and challenging, and even impossible to control. They are based on a mindset that humans are able to precisely manage global-scale systems despite their vast complexity and unpredictability.
All forms of geoengineering are likely to favour those in power, whether corporations or governments of wealthy countries. These technologies provide business opportunities for a small elite, and an excuse for maintaining the present, deeply unjust model of development and excessive consumption by the few, to the detriment of large parts of the world’s population.
As attention is directed towards investment in geoengineering technologies (largely by outside interests), there is also a risk that resources and support will be redirected away from mitigation, adaptation and loss and damage.
Some forms of solar geoengineering would rely on continuously loading sun-blocking particles into the stratosphere in order to mask the warming impacts of greenhouse gases. If the injection of particles were to be suddenly stopped – due to war, geopolitical disputes, devastating impacts on weather systems, or societal collapse–temperatures would quickly spike when the sun-blocking particles fell to the ground. Such a ‘termination shock’ would likely rip ecosystems and societies apart.
Beyond its direct impacts and immense risks, many scholars of peace and conflict and environmental governance also fear that disagreements over how, when and where to apply solar geoengineering could cause new conflicts and wars, and that the technology could even be used as a weapon of mass harm in its own right. There is no evidence from human history to suggest that solar geoengineering deployment could be governable.
There is already immense pressure on land in the Global South, and CDR at the scale needed to impact global heating would exacerbate land grabbing and human rights abuses. . Geoengineering technologies such as BECCS and DAC would add considerably to these pressures, with grave consequences for both people and biodiversity.
Women are at particular risk as their lack of land rights often make them more vulnerable to commercially-driven land dispossession. DAC would also put huge additional indirect pressure on lands in that it would require 100% renewable energy to make any sense climate-wise.
The harnessing of this additional solar and wind energy would require vast additional land areas and critical minerals – much beyond the current, unmet needs by billions of people.
Geoengineering is clearly not compatible with human rights. The UN’s Human Rights Council Advisory Committee states in its report on the ‘Impact of new technologies intended for climate protection on the enjoyment of human rights’ (A/HRC/54/47, 10 August 2023), that because such technologies “are meant to be applied on a global scale, [they] have the potential to affect everyone indiscriminately. They could seriously interfere with the enjoyment of human rights for millions and perhaps billions of people.”
Climate change is one of the most dangerous and pressing challenges facing humanity, but responses that may be as or even more dangerous cannot be justified.
Geoengineering technologies are either highly speculative or have been debunked, and each presents numerous risks that justify their rejection. Here are some of the risks: