Blog 24_ Carbon Copy

"We should use Direct Air Capture techniques to remove all carbon dioxide from the athmosphere and solve the climate crisis", proposes one correspondent. That would not be a good idea.

Direct air capture is a new and developing technology which can remove carbon dioxide from the air. At present it is very energy intensive and for that to change will require a number of research breakthroughs. It is sure to have a role in the future but it is not a silver bullet.

Carbon dioxide (CO2) and Methane (CH4) are the two greenhouse gases typically discussed. CO2 causes around 25% of global warming and CH4 causes 10%. You might be wondering what makes up the remaining 65%? There are some trace elements of other gases involved, but the biggest greenhouse gas of all is water vapour. Why we don't start by eliminating that?

Attempting to remove water vapour from the athmosphere isn't a practical or effective solution. Water vapour is part of the Earth's natural water cycle, moving between the oceans,athmosphere and land through processes like evaporation, condensation and precipitation. Removing water vapour would disrupt these cycles, potentially causing severe consequences for ecosystems, agriculture and weather patterns. Furthermore, water vapour has a very short residence time in the athmosphere - only a few days or weeks.It condenses to clouds and falls as rain, naturally regulating its levels.

If all CO2 were removed from the athmosphere, it would have catastrophic consequences for the planet and all life forms. Plant life requires CO2 for photosynthesis. Without CO2, all plant life would die, leading to the collapse of ecosystems dependent on them. As plants died, oxygen production would cease, endangering all oxygen breathing organisms and leading to mass extinctions.The Earth's average temperature would drop significantly from 15 degrees C today, to around minus 18 degrees C. CO2 is vital for maintaining Earth's climate and supporting life. Its complete removal would render the planet lifeless and frozen.

Prior to the Industrial Revolution CO2 levels in the athmosphere were approximately 280 parts per million (PPM). As of 2024, these levels have risen to 424 PPM which is a more than 50% increase. We need to reduce CO2 levels, not eliminate them.