Can geoengineering slow climate change, or will it be used as an excuse not to cut emissions? – ABC News
In October the United Nations’ climate body, the Intergovernmental Panel on Climate Change, sounded a grim warning.
Global carbon levels from 2010 needed to be cut by almost half by 2030, limiting global warming to 1.5 degrees Celsius, otherwise the world could be locked into catastrophic climate change.
Many governments are falling short of the commitments they made at the 2015 Paris climate change conference to cut fossil fuel emissions.
In the void left by government inaction, scientists have for years been quietly working on extreme, last-ditch solutions to slow global warming.
These solutions — an attempt to re-engineer the climate system — are known as geoengineering.
Critics say there is a risk that climate hacking will give government and industry an excuse to keep burning the planet.
But no matter how fast the world switches to renewable energy, the age of untested, high-risk geoengineering could soon be upon us.
So what are the most likely fixes and would they really work?
Most of these globally ambitious projects are still on the drawing board. But one surprising new technology is up and running.
Nine years ago, Swiss PhD students Christoph Gebald and Jan Wurzbacher formed a company, Climeworks, based on the idea of sucking carbon out of the air. Today, Climeworks has three industrial plants doing just that.
Mr Gebald and Mr Wurzbacher opened their first plant outside Zurich in Switzerland two years ago, quickly expanding to Iceland and Italy.
Giant fans draw in air and capture carbon molecules in filters. The carbon-free air is released back into the atmosphere and the carbon dioxide is super-heated and stored as gas.
Mr Gebald and Mr Wurzbacher believe their fans could eventually remove 10 per cent of the carbon the IPCC wants cut from the atmosphere.
Their immediate plan is cutting 1 per cent by 2025.
“It’s like 300 million tonnes of CO2,” Mr Gebald said.
“And that would require a quarter of a million machines.”
To help cover costs, Climeworks sells the carbon gas to greenhouses to increase plant yields and soft drink companies to fizz their drinks. They are also partnering with Audi to try to recycle it as fuel.
The fans can be placed anywhere and have no dangerous side-effects.
In the developmental stage it costs $US600 ($840) to remove just 1 tonne. Mr Gebald and Mr Wurzbacher are hoping to reduce the cost to $US100 ($140) by 2030.
In 1991, the eruption of the Mount Pinatubo volcano in the Philippines resulted in an unusual side-effect: the lowering of the Earth’s temperature by 0.5 degree Celsius after sulphur particles were sent around the globe.
Today at Harvard University, engineers and physicists are working to see if they can emulate that effect by sending a high-altitude balloon 20 kilometres into the stratosphere to scatter sun-reflecting aerosols.
If successful, specially-modified planes could be sent to scatter tonnes of particles in an attempt to help limit global warming to 1.5 degrees Celsius.
But there are a few things the scientists want to sort out first.
For example, the Mount Pinatubo eruption also damaged the ozone layer.
“We’ve been trying to do a lot to actually fix the ozone layer,” the project’s chief engineer, Professor Frank Keutsch, said.
“And here you now have the idea of introducing something that could destroy it again.”
Professor Keutsch compares stratospheric geoengineering to painkillers, saying they reduce symptoms without solving the real problem.
The Harvard team hopes this form of geoengineering will never have to be used, and wants to make sure the real benefits — and hazards — are known before governments or corporations try it.
The process is incredibly cheap, with estimates it could lower the entire Earth’s temperature for less than $US10 billion ($13.9 billion) a year.
Because this solution is so cheap, it could tempt governments to delay the more expensive and necessary process of transitioning to renewable energy.
Antarctica is a long way away. Unfortunately, much of it could soon be coming to a waterfront property near you.
The Antarctic ice sheet is the size of the US and Mexico combined and its western edge is showing worrying signs of break-up.
In the Hollywood blockbuster doomsday scenario of it collapsing into the ocean, global sea levels would rise more than 3 metres.
One answer, according to ice climatologist and former IPCC contributor Professor Jason Box, is dumping sand.
‘We can slow down melting of the Antarctic ice sheet by piling the sand on the sea floor simply to block warm currents that are already destabilising the whole west Antarctic ice sheet,” he said.
Every coastal city on Earth would escape drowning.
It would take a hell of a lot of sand.
Who can forget the Minerals Council 2015 ad on how amazing coal was?
Many laughed at the claim coal emissions could be cut by 40 per cent. But it has now been put to the test.
At the Petra Nova power plant outside Houston, Texas, a coal-fired generator has been retrofitted with a billion-dollar absorption tower that captures much of the carbon before it is expelled into the atmosphere.
The plant is a pioneer of what the industry likes to call “clean coal”, and has been held up as a model for the future by the Australian Government.
But the 40 per cent reduction claim has been questioned by environmentalists, who point out that a high-emissions gas plant is needed to power the process.
What is more, the captured carbon is pumped into an oil field to break up stubborn oil deposits and extract more carbon-producing oil.
Company spokesman David Knox conceded that rather reduces the environmental benefits of the process, but argues at least it reduces US reliance on other countries’ fuel.
“The oil is the same amount being used, we’re just increasing the domestic production and we don’t have to import as much oil from foreign countries,” he said.
It is a far cry from Donald Trump’s 2016 declaration: “There is a thing called clean coal. Coal will last for a thousand years in this country.”
The coal industry is now promoting so-called HELE plants — High Efficiency Low Emissions — that reduce carbon by burning coal at higher temperatures.
But in most countries they are more expensive to build than wind or solar plants that produce zero emissions.
Even climate commentator Bjorn Lomborg, who has long advocated technology as a better means to cut emissions than switching to renewable energy, said clean coal is still “a mirage”.
Clean coal would certainly be great.
There is not much evidence yet that it is ever going to actually exist.
Climate Hackers airs on Foreign Correspondent at 8pm on ABC TV.