The Earth needs multiple methods for removing CO2 from the air to avert worst of climate change
Posted by admin on 13th December 2019

Concentrations of carbon dioxide in the atmosphere are higher than at any time in human history, and nine of the warmest years have occurred since 2005.

Even with the progress made in introducing alternatives to fossil fuels, gaining energy efficiencies and proposed carbon regulations around the world, avoiding catastrophic impacts on our coastal infrastructure, biodiversity, food, energy and water resources will require more. In particular, many climate researchers like myself believe government needs to advance technology that will actually suck carbon dioxide out of the air and put it away for very long periods.

There are several so-called negative emissions technologies that could remove carbon dioxide from the air, including those aimed at removing CO2 by enhancing natural forest and wetland uptake, using bio-energy in power production and scrubbing CO2 efficiently from air.

As diplomats and policymakers gather to discuss global agreements to reduce greenhouse gas, many believe that negative emissions technologies need to be part of the discussion for how nations will address climate change. But much as there is not a single solution to reducing emissions, no one technology will alone be sufficient to avert the worst effects of climate change.

Matter of scale

In a 2018 consensus study, the U.S. National Academies of Sciences concluded that negative emission technologies will be needed to reduce difficult-to-reduce emissions even if most emissions from burning fossil fuels, agricultural land use and cement production – the top sources of man-made greenhouse gases – could be eliminated. The study noted that direct emission reductions in some sectors, such as air travel, will be always remain more difficult to achieve and will require methods to remove CO2 from the air and store it away.

The concept of carbon capture and storage is to separate carbon dioxide from the emissions of burning fuel, such as those generated at a power plant, and to permanently store them underground.
UK Department of Energy and Climate Change, CC BY-ND

The scale of the problem is daunting. In the U.S. alone, which emits about a sixth of current global CO2, and with global energy needs steadily increasing, emissions to the atmosphere are expected to outpace uptake and the volume of waste gas will only grow. In its latest emissions gap report, the United Nations warned greenhouse gases will continue to rise despite most countries committing to reduce them, calling the forecast for reversing the course “bleak.”

Where should CO2 be safely put away? The most convenient sites appear to be near industrial sources, such as power plants, but they can come with a tangle of issues surrounding underground property rights, overland access, and long-term risks and liabilities near populated areas.