Researchers Warn of Dangers of Climate Engineering

CALIFORNIA – Climate engineering, or geoengineering, is increasingly being discussed as an option to mitigate the impacts of global warming. However, recent research indicates that such technology has the potential to disrupt Earth’s climate system if applied without an adequate understanding of its consequences.

University of California research published in the journal Earth’s Future found that every climate engineering method carries different consequences. Some approaches are assessed to be capable of triggering major changes in regional climate systems, while other methods have a much smaller impact.

“We must be careful when implementing climate engineering proposals before we fully understand what is happening,” said the study’s lead author, Chen Xing, as quoted from Science Daily on Saturday (4/7/2026).

Xing, along with colleague Cali Pfleger, researched the impact of climate engineering on marine ecosystems, focusing on the El Niño-Southern Oscillation (ENSO) phenomenon—the natural cycle of sea surface temperature changes in the Pacific Ocean that influences weather patterns worldwide.

In the study, the team compared two climate engineering approaches that both aim to reflect a portion of sunlight back into space to lower Earth’s temperature.

The first approach is Marine Cloud Brightening (MCB), which involves spraying sea salt particles into the lower atmosphere to make clouds brighter, thereby reflecting more sunlight. The second approach is Stratospheric Aerosol Injection (SAI), which disperses sulphate particles into the stratosphere to achieve a more even cooling effect.

Simulation results showed that implementing MCB in the eastern Pacific Ocean could reduce the strength of ENSO by approximately 61 per cent.

“It is very difficult to make ENSO change that much in such a short period of time,” said University of California Associate Professor Samantha Stevenson.

According to the researchers, this change is triggered by the cooling of the sea surface and reduced rainfall due to changes in cloud characteristics. These conditions then affect atmospheric circulation, strengthening winds along the equator and increasing the process of cold sea water upwelling, which ultimately weakens ENSO.

Xing stated that the research findings show that the MCB approach in the eastern Pacific Ocean region has the potential to trigger unintended consequences for the global climate system.

“Do not perform MCB over the eastern Pacific Ocean because it could trigger a very powerful chain reaction due to the loss of ENSO,” he said.

In contrast, the SAI approach did not show a significant influence on ENSO because the dispersed particles spread more evenly throughout the atmosphere, thus not drastically altering the regional climate balance.

Nevertheless, Stevenson emphasised that these findings do not mean all MCB approaches should be abandoned.

“We are not saying that all MCBL will kill ENSO. We are only saying that this happens if you do it in this specific region,” she said.

The research also warns that climate engineering could lead to other impacts, including a reduction in the intensity of sunlight required for photosynthesis. This condition has the potential to affect agricultural productivity as well as marine ecosystems, which support the food chain and produce much of the Earth’s oxygen.

“Two interventions could achieve the same global temperature reduction target, yet have extraordinarily different regional climate impacts. The most important question is: have we considered all the possible consequences?” said Stevenson.