“If you want to be confident to get to 1.5 degrees you need to have solar geo-engineering,” says one scientist.
Scientists are sucking carbon dioxide from the air with giant fans and preparing to release chemicals from a balloon to dim the sun’s rays as part of a climate engineering push to cool the planet.
Backers say the risky, often expensive projects are urgently needed to find ways of meeting the goals of the Paris climate deal to curb global warming that researchers blame for causing more heatwaves, downpours and rising sea levels.
The United Nations says the targets are way off track and will not be met simply by reducing emissions for example from factories or cars – particularly after U.S. President Donald Trump’s decision to pull out of the 2015 pact.
They are pushing for other ways to keep temperatures down.
In the countryside near Zurich, Swiss company Climeworks began to suck greenhouse gases from thin air in May with giant fans and filters in a $23 million project that it calls the world’s first “commercial carbon dioxide capture plant”.
Worldwide, “direct air capture” research by a handful of companies such as Climeworks has gained tens of millions of dollars in recent years from sources including governments, Microsoft founder Bill Gates and the European Space Agency.
If buried underground, vast amounts of greenhouse gases extracted from the air would help reduce global temperatures, a radical step beyond cuts in emissions that are the main focus of the Paris Agreement.
Climeworks reckons it now costs about $600 to extract a tonne of carbon dioxide from the air and the plant’s full capacity due by the end of 2017 is only 900 tonnes a year. That’s equivalent to the annual emissions of only 45 Americans.
And Climeworks sells the gas, at a loss, to nearby greenhouses as a fertiliser to grow tomatoes and cucumbers and has a partnership with carmaker Audi, which hopes to use carbon in greener fuels.
Jan Wurzbacher, director and founder of Climeworks, says the company has planet-altering ambitions by cutting costs to about $100 a tonne and capturing one percent of global man-made carbon emissions a year by 2025.
“Since the Paris Agreement, the business substantially changed,” he said, with a shift in investor and shareholder interest away from industrial uses of carbon to curbing climate change.
But penalties for factories, power plants and cars to emit carbon dioxide into the atmosphere are low or non-existent. It costs 5 euros ($5.82) a tonne in the European Union.
And isolating carbon dioxide is complex because the gas makes up just 0.04 percent of the air. Pure carbon dioxide delivered by trucks, for use in greenhouses or to make drinks fizzy, costs up to about $300 a tonne in Switzerland.
Other companies involved in direct air capture include Carbon Engineering in Canada, Global Thermostat in the United States and Skytree in the Netherlands, a spinoff of the European Space Agency originally set up to find ways to filter out carbon dioxide breathed out by astronauts in spacecrafts.