Anyone who plans to cool down the Earth or dim the sun should be led by the most affected by climate change

The countries of the “global north” are responsible for 92% of excess global emissions, according to a 2020 study in The Lancet Planetary Health. Yet it is the rest of the world – the “global south” – that disproportionately bears the brunt of climate change. While emergency measures to reflect more sunlight could temporarily mitigate the worst effects, it must also improve the safety of those most vulnerable.

Somewhere between 15% and 40% of CO₂ emissions will remain in the atmosphere Longer than 1,000 years. Since so much climate change is already “locked in”Any strategy to address it based solely on emissions reductions, no matter how quickly they are reduced, would still lead to catastrophic ice losses within the Arctic and Antarctica and sea level rise and loss of low-lying nations and hundreds of million of climate refugees. It would still result in global food and water scarcity, massive flooding and wildfires, and a permanent loss to ecosystems. These terrible changes will continue unabated to the global south.

We believe temporary schemes, which can partially protect some of the Earth’s surface from incoming solar radiation, are the best way for major disaster to be avoided. This is at least until emissions reductions can be increased and carbon capture and stored can be scaled-up.

There are two main approaches, each with very different characteristics. The first involves releasing tiny reflective particles into upper atmosphere that reflect sunlight back into space. Known as “stratospheric aerosol injection”, this process would cool the globe for several years or more, but it is controversial because of the potential for global and long-lasting Unintended consequences.

The other approach, “marine cloud brightening”, involves ships generating sea spray. The salt crystals formed by the water droplets are carried up into the atmosphere. This gives clouds something to form around, and helps cool the planet since the clouds formed by small salt crystals reflect more of the sun’s energy.

As these particles are returned to the ocean in a matter of weeks, it is much easier to “turn off” cloud brightening if ever it was deemed necessary. This makes it more appealing to policymakers and the general public.

Real-world experimentation

Climate models are computer simulations that provide the majority of our knowledge on these technologies. However, there have been some real-world trials. China, for instance, has used particles to inject into the atmosphere in an attempt to seed new clouds. encourage precipitationIn remote mountains, and Covered a glacier in clothto stop it melting. Authorities in Peru once Painted a mountain whiteTo reflect more heat and protect its glacier, darker colours are more absorbent. There are plans to protect Australia’s Great Barrier Reef with cloud brightening.

These initial steps provide valuable insight into the potential and limitations of these technologies. However, further research and funding is required. Learn about the risks and limitations.

There are technical questions to be addressed, but there are also critical social science issues – research will need to examine the contexts in which these kinds of technology develop, with a focus on dimensions of gender, ethics, justice, equity and sustainable development among communities most affected by climate change. These communities must be able to lead the development and deployment of safe, inclusive technologies. This will help to strengthen global capabilities to combat climate change.

Potential to prevent catastrophe

It is difficult to quantify the cost of climate injustice. However, communities least able to adapt, perhaps due to a lack of resources, pre-existing conflicts, or because they’re based in an area already prone to droughts or hurricanes, may well argue that no amount of climate change is safe. Technological advancements like marine cloud brightening offer a possible path to averting catastrophe. However, this must be further developed.

We must examine technologies that could save many lives and stop the worst effects of climate changes until mitigation policies catch up to reality. It is important that those most affected by climate change are involved in decisions regarding how research should be conducted and whether interventions should take place.

One option is to establish research centers in the global south. Exchange between centres could be co-hosted by an inter-governmental body such as the UN’s environment programme UNEP, together with civil society and academia. Similar events occurred during the Green Revolution of the 1950s and 1960s, when new agricultural technologies spread across the globe. This can be seen today in humanitarian situations.

Regional bodies, such as the African Union and the Association of Southeast Asian Nations, could get involved, though the question of who will actually deploy these technologies – which country’s navy or air force will spray the particles – should be decided by international agreement. The nations most affected by climate change (and those least able to adapt to it) should be leaders in directing the research and overseeing the deployment of the technology.