Global geoengineering experiments from the Arctic to the Great Barrier Reef are being funded by the British government. They will test the particles of sunlight in the stratosphere, use sprays of sea water and pump water on sea ice to thicken it.

The Advanced Research and Invention Agency (ARIA), the government agency supporting the program, said it is crucial to obtain this "critical lost scientific data." If proven safe, geoengineering could temporarily cool the planet and provide more time to deal with the root cause of the climate crisis: the burning of fossil fuels.

Before continuing, the experiment will be small-scale and rigorously evaluated, Aria said. Other projects in the £56.8 million plan will model the impact of geoengineering on the climate and study how to manage it internationally.

Geoengineering has caused controversy, with some scientists calling it a "dangerous distraction" from reducing emissions and paying attention to unexpected climate impacts. After strong opposition, some previously planned outdoor experiments have been cancelled.

But given that the world has failed to stop the increase in emissions so far and operated in a recent record-breaking hot period, supporters of solar engineers say it is crucial to study the technology when emergency brakes are needed. The ARIA program, along with another £10 million project, makes the UK one of the world's largest funders for geoengineering research.

“Decarbonization is the first and best opportunity to avoid these turning points,” said Professor Mark Symes, director of ARIA Programs. “But the current trajectory puts us in danger of triggering some turning points, no matter what happens in net zero, so we do need to think about the final situation.

“The focus of the program is to explore and study as transparently as possible whether the proposed cooling method can be used safely,” he said. “If these tipping points are triggered, life in the UK can become very difficult.”

“If science can show us the incredible biodiversity of beautifully designed seawater sprays that protect and preserve the incredible biodiversity of the large barrier reefs, isn’t that something we want to know?” said Ilan Gur, CEO of Aria.

Professor Raymond Pierrehumbert of Oxford University criticized the news: "Solar geoengineering has a huge and disturbing impact on the global society. UK funding provides a dangerous precedent for other governments to jump on the trend, and opening the door to field experiments without any national or international government is the height of welfare."

"Solar engineering is inherently unpredictable, and risks further undermine already broken climate systems. Carrying out small-scale experiments has the potential to normalize highly controversial theories and accelerate technological developments and accelerate slippery slopes, thus creating landslides in full swing."

Most geoengineering proposals are designed to prevent sunlight from reaching and heating the Earth's surface. However, solar radiation management (SRM) has serious unintended consequences, such as transfer of rainfall that is critical to food production. Some private companies are already working on geoengineering. This makes it even more important to build a scientific evidence base, Goul said.

ARIA-funded experiments include sending weather balloons to the stratosphere above the United States or the United Kingdom. Mg samples of non-toxic mineral dust will be exposed to high altitude conditions and will be recycled to evaluate how the properties of the particles change over time.

Three other experiments will test how the seawater spray or charge delivered by the drone can sow small droplets, so that the clouds on the ocean reflect more sunlight. One will expand its current work, a major obstacle reef in crisis due to global heating and could reach a scale of 100 square kilometers, while another will be conducted on the British coast.

The fifth experiment will involve pumping water on Canadian sea ice in winter, up to a scale of 1 square kilometer. The water will freeze during the summer and keep the ice cap for longer. Bright white ice reveals much more than dark oceans reveal sea ice in warm waters.

Public environmental impact assessments will be conducted and local communities will be consulted before any outdoor experiments are conducted. Aria said there is also an independent oversight committee as part of the approval process, led by Professor Piers Forster, a leading climate scientist, and chairs, including members from India and Ghana.

The ARIA program will also use modeling to determine its feasibility, evaluating the spatial reflectors that place the sunshade onto the track. "This is the most speculative of all the methods we fund," Symes said. The volcanic eruption naturally injects particles into the atmosphere, and another project will fly drones through feathers to measure the effect of particles.

Seven modeling teams will study the impact of geoengineering on climate and ecosystems, especially in developing countries, with approximately 85% of the population living in life. There will be five five teams exploring the wider social impact of geoengineering in terms of ethics and governance, such as how to agree and manage any future deployment.