New technologies for controlling carbon dioxide levels in the battle against global warming

Global warming is an enormous concern. Scientists continue to produce more and more undisputable evidence showing both the dangers that global warming pose to our planet in the not-too-distant future, and its link to our continued over-production of carbon dioxide.

 

What’s wrong with carbon dioxide?

Carbon dioxide (CO₂) is essential for life on earth. It is produced by all aerobic organisms – including us - as an end product of respiration, and it is absorbed by plants during photosynthesis. But since the industrial revolution began, the concentration of CO₂ in the earth’s atmosphere has increased by about 43%. Because it is a greenhouse gas and traps in heat from the sun, this increased CO₂ is contributing to a steady increase in the global climate which is resulting in rising sea levels and extreme weather conditions. And increases in the atmosphere also result in an increased uptake into the oceans where the CO₂ dissolves to form carbonic acid, causing a measurable decrease in the pH of oceans. This is harming marine life and has led to the coral bleaching which currently endangering the entire existence of the Great Barrier Reef.

The overall outcome if this continues will be catastrophic to our environment, and in the interim will be reflected by a dramatic crash in the global economy.

 

What can we do?

There are currently 2 main objectives to deal with the escalating levels of CO₂, in an attempt to limit global warming.

Firstly, countries worldwide we are aiming to decrease the amount of CO₂ that they produce. This is thanks to the COP21 Paris Climate deal which was agreed 6 months ago, and signed by representatives from 196 countries. Collectively we are now trying to switch our sources of energy away from fossil fuel – a high producer of CO₂ - as we look to renewable alternatives such as solar and wind power, and enhance how we store energy with improved storage technologies.

The second aim is to decrease existing CO₂ levels in the atmosphere and there is now exciting evidence that may be achievable.

 

Carbon capture and storage

A carbon capture and storage (CCS) project, carried out as a collaboration between the University of Iceland, CNRS in Toulouse and Columbia University, has successfully pumped CO₂ underground where it has been turned into stone, providing evidence that CO₂ can be safely captured and stored permanently underground. The CO₂ was pumped into volcanic rock in Iceland where it reacted with basalts to form the carbonate minerals that make up limestone. The transformation of over 95% of the 175 tonnes of CO₂ injected at the site in Iceland took two years, which was much faster than the hundreds or thousands of years expected. This project, called CarbFix requires volcanic basaltic bedrock which is widely located, making this process viable around the world, although it is predominantly on the ocean floor. Reykjavik Energy are now running a larger test to bury around 10000 tonnes of CO₂.

Other methods of CCS are also being explored. Exciting new research at the Weizmann Institute of Science in Israel demonstrated that when scientists introduced components required for the Calvin cycle pathway for carbon fixing into E.coli, some of the bacteria evolved over time to utilise CO₂, which coincided with changes in their DNA that could be mapped by the researchers. Although the bacteria still release CO₂, the scientists are hoping that the information they have gained will help them to develop organisms that will more efficiently convert CO₂ into sugar.

 

Given that the world’s power stations, cars and so on have generated approximately 37 billion tonnes of CO₂ this year, the CarbFix and bacteria CCS provides just a fraction of what may be required in the fight against global warming. But this is the first evidence that carbon capture is possible, so - together with a shift towards renewable energy - it holds great promise for the future control of CO₂ in the battle against global warming.