Scientists have been warning for years that climate change is a very real threat that mankind faces. But many, including prominent world leaders, have ignored this. This may have resulted in inadequate response to the problem and we may be at a point of no return. These fears may be true according to researchers who say that global warming will continue even if greenhouse gas emissions responsible for it are reduced to zero.
Even if humanity stopped emitting greenhouse gases tomorrow, Earth will warm for centuries to come and oceans will rise by metres, according to a controversial modelling study published recently. Natural drivers of global warming — more heat-trapping clouds, thawing permafrost, and shrinking sea ice — already set in motion by carbon pollution will take on their momentum, researchers from Norway reported in the Nature journal Scientific Reports.
“According to our models, humanity is beyond the point-of-no-return when it comes to halting the melting of permafrost using greenhouse gas cuts as the single tool,” lead author Jorgen Randers, a professor emeritus of climate strategy at the BI Norwegian Business School told.
According to the researchers, the only way to do it is to extract greenhouse gases from the atmosphere and store them so that they do not go back into it. Using a stripped-down climate model, Randers and colleague Ulrich Goluke projected changes out to the year 2500 under two scenarios: the instant cessation of emissions, and the gradual reduction of planet-warming gases to zero by 2100. The data showed that if emissions stopped for good in 2020, sea levels in 2500 would still be more than 8 feet (2.5 meters) higher than in 1850. To prevent the projected 3-degree-Celsius temperature increase, greenhouse-gas emissions would need to have ceased entirely between 1960 and 1970, the model found. In that sense, Earth blew by a climactic point of no return 50 years ago — before much of the public understood the realities of climate change.
In an imaginary world where carbon pollution stops with a flip of the switch, the planet warms over the next 50 years to about 2.3 degrees Celsius above pre-industrial levels — roughly half-a-degree above the target set in the 2015 Paris Agreement — and cools slightly after that. Earth’s surface today is 1.2C hotter than it was in the mid-19th century when temperatures began to rise.
Earth’s temperatures are already on track to blow past the Paris agreement’s goals. Last year was the second warmest on record for surface temperatures and the hottest ever for oceans. Polar melting is on track to raise seas 3 feet by 2100 and threatens to displace hundreds of millions of people. What’s needed, Randers said, is for companies and governments to “start developing the technologies for large-scale removal of greenhouse gases from the atmosphere.”
In technical terms, that strategy is known as carbon capture and storage (CCS). To prevent further warming after emissions have stopped, the new study found, at least 33 gigatonnes (36.5 billion tons) of carbon dioxide would need to be sucked out of the atmosphere each year. That’s roughly the total amount of carbon dioxide the global fossil-fuel industry emitted in 2018 (36 gigatonnes).
Power plants in the US, Canada, and Switzerland have already started utilizing CCS to lower their emissions. In 2014, the Boundary Dam Power Station in Saskatchewan became one of the first in the world to successfully use the technology. In total, 21 commercial-scale carbon-capture projects are operating around the world, and 22 more are in development, according to the Center for Climate and Energy Solutions. These projects typically store carbon deep underground in depleted oil and gas fields or in bioreactor containers filled with algae that eat carbon dioxide.
