Orca. The answer to global warming?

Michael – Thursday

ORCA, Iceland

Last week a new plant opened in Iceland at the Hellisheidi power plant near Reykjavik. Its purpose is to filter carbon dioxide (CO₂) out of the air and convert it to a solid, thus trapping the gas and keeping it out of the atmosphere for good, or at least for a very long time. The plant can remove 4,000 metric tons of CO₂ from the atmosphere every year, and that’s a lot of gas. On the other hand, it isn’t really very much. By 2050, if there is no reduction of CO₂ generation, we will need to remove more than a billion tons a year for carbon neutral.

In a way the technology is simple. CO₂ readily combines with other chemicals to form carbonates which are stable solids. In practice, though, the engineering is clever. Air is forced through spongy filters in large cylinders that collect about 90% of the CO₂ in the air. Then the cylinders are sealed and heated to around 100 degrees centigrade which frees the gas again. It’s mixed with water and pumped into basalt caverns where – over years – it reacts with the rock and deposits as carbonates. Of course, the CO₂ collected can also be used for commercial purposes such as gas for carbonated drinks. But then it goes back into the atmosphere again. So in reality, this is a technology that governments have to support (as Iceland has).

There are some obvious other issues. You need a suitable underground storage location for the CO2 to react and solidify. That cuts down the suitable locations, although, of course, the gas can be stored under pressure and shipped elsewhere. Then there is the energy to run the process. It works in Iceland because Orca has been built next to a geothermal energy plant which taps the free, clean, heat energy that powers the whole country. Again, that’s a special feature of Iceland. I’m certainly not writing the technology off, but it’s not the solution.

Seeding cloud with reflective particles

In fact, there is no single solution. There are plans to block some of the sun’s energy (a high level dust cloud has been suggested by Bill Gates, and aluminium reflectors in space is another). We need to look at everything. In the meanwhile, if everyone makes a small contribution to less fossil fuel energy usage, it may buy the time to bring the clean energy and other approaches to fruition. We can get through this.