Scientists are increasingly looking at global warming as a waste disposal problem. They say that thinking of emissions in terms of trash that needs to be taken out may draw more attention to something called negative carbon emissions — the process of physically removing carbon dioxide from the air to reduce its concentration in the atmosphere.
“It has been estimated that the warming due to one unit of CO2 emissions is roughly constant for about 1,000 years, and then it gradually drops. So if you want to improve on that, you have to remove CO2 yourself,” said Klaus Lackner, director of the Center for Negative Carbon Emissions at Arizona State University.
Research shows that keeping global warming from exceeding 2°C (3.6°F) under the Paris Climate Agreement may not be possible without some form of negative carbon emissions. Atmospheric carbon dioxide concentrations, which breached 400 ppm atop Hawaii’s Mauna Loa for the first time in 2013, are expected to continue climbing unless humans take significant steps toward burning fewer fossil fuels. The remote reaches of Antarctica crossed the 400 ppm threshold in May for the first time in 4 million years.
CO2 concentrations are rising about 2.2 ppm annually, and the earth is expected to warm to 2°C when concentrations reach about 450 ppm. If today’s carbon dioxide emissions hold steady without reductions, it will take about 22 years to reach 450 ppm, and it’s possible the earth will overshoot that 2°C target if emissions continue increasing, Lackner said.
“Without negative emissions, a 2°C target is very difficult; a 1.5°C target is virtually impossible,” he said.
Lackner and other researchers say it’s time to find ways to remove the waste that’s collecting in the atmosphere after it’s expelled from all of humanity’s tailpipes and smokestacks.
“We are currently dumping our rubbish straight into the atmosphere without having to pay for it although we know it is harmful,” said Joeri Rogelj, an energy research scholar at the International Institute for Applied Systems Analysis in Austria. “Carbon dioxide removal is thus a way to clean up the mess we made.”
Source: Climate Central