Carbon capture gains momentum as a solution to fight global warming but reservations remain

GEROLSTEIN, Germany: Nested in the forested foothills of western Germany’s Gerolsteiner Dolomiten nature reserve are rocks that are approximately 200 million years old.
These rocks, formed over geological periods hundreds of millions of years ago, could be part of the solution to today’s climate problems.
“These rocks are solid,” said Franz May, from the German Federal Institute for Geosciences and Natural Resources, as he pointed out sandstone to CNA.
“There are some fractures and tiny pores in between the sand grains of the sandstone – these pores are where the CO2 (carbon dioxide) can be put in and easily penetrate into the rocks.”
The geologist was explaining the role the nature reserve’s rocks can play in carbon capture and storage (CCS), a concept touted to reduce carbon emissions from industrial processes.
The technique involves the capture of carbon dioxide, generally from large point sources like power generation or industrial facilities that typically use fossil fuels.
The captured carbon dioxide is then compressed and stored in ways that do not affect the atmosphere, such as deep underground in depleted oil and gas reservoirs.
Scientists said specific geological conditions, such as sandstone deposits, can act as natural storage tanks for the gas.
Carbon is already stored underground naturally in rocks and sediments.
For example, springs with carbonated water – sometimes called soda springs – can be found in pockets of the globe with certain geological formations such as volcanic rocks. Gerolsteiner Dolomiten, too, is famous for its natural sparkling water.
This means carbon dioxide emitted by human activity can also be stored and sealed underground using the same types of rock formations, said researchers.
Below the natural reserve’s earth surface, millions of square kilometres of similar rock formations stretch across Germany to as far as France, the Netherlands and the United Kingdom.
Eabhard Pernot, who leads the Zero Emissions Platform, a Brussels-based think tank advising the European Union on carbon management strategies, said CCS could be one way to deal with the huge amount of carbon dioxide produced by heavy industrial facilities such as steel mills.
Several European countries are currently in talks to use these types of so-called reservoirs as a way to store carbon and combat climate change. 
“We have technologies which are available to capture CO2, purify it, transport it and store it, often in the same places that we take oil and gas from – in deep rock formations hundreds of metres under the ground,” he said.
“It binds itself to the rock … and it stays there permanently … most importantly, (this) keeps CO2 out of the atmosphere.”
However, opinion has been split about the use of carbon capture and storage as a climate solution.
Critics warn that the technology is still at a preliminary stage – largely untested, unproven and very expensive.
Climate advocates also say capturing carbon should not be seen as an alternative to cutting emissions.
The United Nations’ Intergovernmental Panel on Climate Change pointed out that while carbon capture can help mitigate climate change, its deployment is limited.
German Member of Parliament (Bundestag) Jorg Cezanne said that CCS utilisation is finite and associated with additional risks.
“From a logical point of view, it would make sense to wait and see what residual emissions really remain, for which storage may then be the only solution – and then we can talk about it,” he said.
Some governments, including Germany’s, have said that they will not support storing carbon dioxide underground for now, amid fears of community pushback over leaks.
But Berlin is exploring opening up the practice under the seabed along the country’s northern coastline.
German authorities are also working with the private sector to capture carbon during production using industrial facilities, including cement plants.
Cement is one of the most widely-used substances in the world. But the industry is responsible for about 8 per cent of planet-warming carbon dioxide emissions, higher than aviation.
Daniel Rennie, CEO of carbon dioxide mitigation firm Leilac, said his business has built plants in Germany and Belgium to pilot the capturing of about 20 per cent of carbon dioxide from cement plants’ throughput.
“Cement has been around for thousands of years and having this big change where we (are now) addressing these CO2 emissions is a big moment,” he said.
While the rollout of CCS projects remains far from wide-spread, industry insiders believe interest will continue to grow as nations and businesses look for solutions to meet strict greenhouse gas reduction targets.