Around the world, ambitious projects are testing everything from seeding clouds with chemicals to pouring artificial whale excrement into the sea.
The goal is to remove CO2 from the atmosphere via so called ‘geoengineering’ and ‘carbon capture’ processes – and help to mitigate climate change.
Geoengineering sees heat from the sun reflected back into space to limit climate change, while ‘carbon capture’ captures CO2 from the air, either directly or by capturing it in rain among other techniques.
Experts speaking to DailyMail.com say that research into these technologies is well under way – with experiments rolling out through this year.
‘Blocking the sun’ with sulfur particles
The White House cautiously supported further research into an idea straight out of science fiction – ‘blocking the sun’ to cool the atmosphere – in a report last year.
The federally mandated report said that there is ‘a compelling case for research to better understand both the potential benefits and risks’.
Large projects are investigating the benefits of cloud brightening
The idea is backed by tech billionaire Bill Gates, who financed a large Harvard study into the feasibility of flying jets into the atmosphere on thousands of missions to release carbonate dust, cooling the planet.
The project was abandoned after protests from indigenous groups.
An Israeli startup called Stardust Solutions is testing a system to spread reflective particles around 60,000 feet up, to reflect sunlight away from Earth.
Brightening clouds over the sea
Another technique which solar geoengineering advocates believe could work is ‘Marine Cloud Brightening’ where clouds over the ocean are injected with tiny droplets to make them brighter and more reflective.
A $64.5 million project from Southern Cross University is to spray a mixture including sea salt into low altitude clouds in an effort to cool the waters around the Great Barrier Reef.
Marine cloud brightening hopes to reflect sunlight by delivering materials (including sea salt) to clouds such as stratocumulus to rapidly reduce warming.
It mirrors an effect caused by pollutants released from ships.
Some scientists suggest that solar geoengineering could spark ‘termination shock’ when it ends, where temperatures rebound rapidly if the geoengineering flights are stopped.
Others have warned that it might spark conflict, for instance if one nation used geoengineering to cool a particular area and it caused problems in another.
Dr. Jens Holtvoeth, Senior Lecturer in Geology, School of Health & Life Sciences at Teesside University told DailyMail.com, ‘Solar engineering seeks to provide a quick measure to temporarily cool the Earth’s atmosphere during the time it takes to bring down the concentrations of the main atmospheric greenhouse gasses, carbon dioxide and methane, which is a slow process.’
‘We do know that the risk of severe environmental damages resulting from solar geoengineering measures, such as injecting large amounts of sulfuric compounds into the atmosphere, is enormous.
‘While some cooling may be achieved, the artificial changes in temperature may also lead to a redistribution of precipitation that does not merely revert the patterns brought by climate change.
‘The changes in rainfall distribution would also affect terrestrial ecosystems and agricultural production in ways that are currently unforeseeable.’
Saving the planet with whale poop
An experiment using artificial whale excrement (poop) aims to suck up carbon dioxide from the atmosphere thanks to phytoplankton.
Phytoplankton suck carbon dioxide out of the atmosphere, with researchers hoping to boost the amount of CO2 absorbed by the oceans from 30 to 50 percent.
Whale poop helps to control global warming
Phytoplankton blooms suck up carbon dioxide — one of four main greenhouse gases that contribute to climate change. After feeding on the carbon dioxide, phytoplankton release oxygen in return.
Professor Sir David King, the Chair of Cambridge University’s Centre for Climate Repair hopes that the technology – using artificial whale excrement to ‘feed’ plankton – could capture half of the world’s global greenhouse gas emissions.
Soaking up CO2 using crushed rocks
The natural carbon-absorbing abilities of rocks could be used to ‘suck’ CO2 from the atmosphere in huge quantities.
Antti Vihavainen CEO and Co-Founder, of carbon-crediting and CO2 removal firm, Puro.earth, told DailyMail.com,’Carbon Dioxide Removal is a process of removing carbon from the atmosphere and – crucially – storing it for hundreds or thousands of years.
Crushed rocks could help to ‘bind’ CO2 and curb global warming
One technique uses enhanced weathering of rocks, mimicking natural processes which remove 1.1 Gt of CO2 from the atmosphere per year, the equivalent emissions to 239 million cars.
Vihavainen said that in enhanced weathering, ‘it is fast-tracked from thousands of years to decades, by crushing large silicate rocks into fine particles or gathering residual rocks from other processes, such as quarry operations, and applying rocks to soil.’
Vihavainen added: ‘It comes with double benefits too- not only is it removing carbon from the atmosphere and storing it for over 1000 years, but there are huge agricultural benefits when the rocks are spread on fields: less need for traditional fertilizer and improved soil quality.
‘The ERW practitioners are still collecting data from early trials and improving the models for predicting the speed of carbon sequestration.
Sucking CO2 out of the air
Direct Air Capture (DAC) is one of the most ambitious – and expensive – ways to deal with climate change, using chemical reactions to pull CO2 out of the air.
There are more than 100 DAC projects around the world, according to the International Energy Agency.
Direct Air Capture ‘sucks’ CO2 out of the air
Heirloom unveiled a direct-air-capture facility in California in November 2023
In America, start-up Heirloom unveiled a direct-air-capture facility in California in November 2023, using limestone to capture CO2 from the atmosphere.
Shashak Samala, founder and CEO of Heirloom said that the facility is ‘is the closest thing on Earth that we have to a time machine, because it can turn back the clock on climate change.’