Techniques to remove carbon dioxide may harm the environment, according to Phil Williamson, an environmental scientist at the University of East Anglia. The scientist suggests that cutting down carbon emissions is more effective and a less expensive way to alleviate global warming.
“The aim is to have a balanced global carbon budget. For that to work, from now on we have to think of matching the addition of greenhouse gases to the atmosphere with their subsequent removal,” Williamson says in a statement. “Climate modellers estimate that as much as 600,000 million tonnes of CO2 may need to be extracted from the atmosphere by 2100 to deliver the main goal of the Paris agreement.”
An article, published in Nature, claims that more research should be done to further understand the complete effects of “geoengineering” projects. Williamson adds that nations have agreed to limit the global temperature increase but if cutting down carbon emissions is not possible, then world leaders should plan on how to remove carbon dioxide from the atmosphere safely.
If carbon emissions will not be reduced, then the removal should begin in less than four years, removing billions of tonnes annually by 2100 to meet the agreed global temperature increase. However, Williamson points out that removing CO2 is expensive and not completely understood so nations around the globe might as well cut down their CO2 emissions as quickly as they could.
Fertilising the oceans to increase the growth of plankton and seaweed, increasing the natural storage of carbon in biomass and forest soil through large-scale tree plantations, using chemicals to remove CO2 and storing it underground, using straw and timber as construction materials, placing silicate rocks on the ground to absorb CO2 and adding biochar, carbon from slightly-burnt biomass, are just some of the plans that have been raised to remove CO2 from the atmosphere.
Williamson exemplifies planting of bioenergy crops, which could use hundreds of millions of hectares of land, will destroy natural habitats. Moreover, the effects of bioenergy crops on the climate are poorly understood and doing this is too expensive.
“The crucial thing now is that governments and other funding agencies need to invest in new research to investigate the viability and safety of the ’emit now, remove later’ approach,” Williamson notes. “Some of the proposed CO2 removal schemes might provide a win-win for climate and the environment; others might be lose-lose. Present climate policy assumes that one or more of them will work at the scale required, yet we just don’t know if that is the case.”