Wednesday, January 22, 2014

A letter from Prof. Olaf Schuiling to the Dutch Government

In the pursuit of scalable and sustainable ways of removing GHGs from the atmosphere, VEC has encountered a wide range of approaches and opinions! In the VEC guest blog, Enhanced Weathering advocate and head of VEC finalists The Olivine Foundation Prof. Olaf Schuiling describes why he felt compelled to write to the Dutch govenrnment recently:

After a long hesitation, I have sent an appeal to the Dutch Parliament. The Minister of Economic Affairs of the Netherlands has requested Parliament to allot another 150 million Euro for the further construction of a Carbon Capture and Storage system under the North Sea. I have asked Parliament to refuse this request.

Years ago, when it became clear that we should capture and store CO2 to counteract climate change, it was understandable that politicians and managers embraced the CCS solution. It follows the usual response in wasteland, when you have waste, collect it and bury it underground. They didn’t realize that nature operated already successfully during the past 4.6 billion years a different and highly effective method by which the CO2 that escapes from the Earth (mainly by volcanoes)  is captured and stored safely in carbonate rocks (limestones and dolomites). Without that process, known as weathering, there would be no life on Earth. Our planet would be like our sister-planet Venus, with an atmosphere of almost pure CO2 at a pressure of 75 bars and a surface temperature of 4600C.

“if you walk in the Dolomites, or sail along the Cliffs of Dover you are face to face with the storehouses of CO2 of the Earth”

During weathering, basic silicates like the ubiquitous mineral olivine react with liquid water and CO2, producing magnesium bicarbonate solutions. These are carried by rivers to the sea, where corals, shellfish and plankton turn them into limestones and dolomites. These rock formations are the ultimate stores of CO2 on Earth, so if you walk in the Dolomites, or sail along the Cliffs of Dover you are face to face with the storehouses of CO2 of the Earth.

The atmosphere is a well-mixed reservoir at a time scale of months, so for the climate it makes no difference where on earth the CO2 is captured. All CO2 molecules are equal, so the origin of the CO2 to be captured is equally irrelevant. In my opinion, climate policy should therefore be formulated as follows:

We must capture as much CO2 as possible, anywhere on Earth, in a safe and sustainable way at the lowest cost possible.

Does fossil-CCS fulfil any of the above 3 criteria? It can be argued as not entirely safe, not very sustainable, and it can be expensive to install on new and existing plants. In the meantime a number of cheaper and more sustainable options have been proposed, like the storage of biochar in soils, the removal of CO2 from the atmosphere with chemical and process engineering, and mineral carbonation – the major process that has always removed CO2 from the atmosphere and stored it safely as a solid component of rocks.

“more work needs to be done to understand these processes. However, don’t mistake that for a reason for inaction”

A proposal for mineral carbonation of olivine was submitted to the Virgin Earth Challenge with the title “Let the Earth help us to save the Earth”. The olivine option is not so much a ‘technology’ in the classical sense, but more a general concept that can be applied in many sectors of society. Projects based on enhanced weathering of olivine and related minerals have been formulated for agriculture, forestry, roads and biking paths, buildings, coastal defense, firefighting, playgrounds, suppression of poisonous dinoflagellate and cyanobacteria blooms, diatom farms for biodiesel production, mining, mineral waters, olivine as a green fuel, olivine in environmental applications, natural emissions of CO2 for carbon capture and miscellaneous. My colleagues in this field point out correctly that, as in nature, the rates and speed of the reaction of minerals like olivine can vary greatly in different situations found in the natural world, and that more work needs to be done to understand these processes. However, don’t mistake that for a reason for inaction, whilst we may be unsure of the absolute potential, we are sure that the potential is there. And, as in nature, with such a wide range of applications for weathering minerals in our human activities, virtually everybody can participate in their own field (literally!) and help move these techniques forward in the fight to counteract climate change and ocean acidification.

When it comes to combating climate change and building a sustainable future, there are a lot of interesting and potentially very helpful actions and developments to be embraced. However, as I know the concept of Enhanced Weathering shows, we must never forget that, in ensuring a safe operating environment for life on this planet, nature is our best ally.

Olaf Schuiling, the Olivine Foundation

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