One of the participants said that to sequester carbon by reacting it with silicate rock such as peridotite, you need to either transport the CO2 to the rock or transport the rock to the CO2 source, either of which may cost an unacceptable amount of energy. That's not actually true: CO2 circulates, so if you just expose new rock to weathering, you're sequestering carbon. Also, transporting rock doesn't have to cost energy: if you run empty trains up a mountain and bring full ones down, the energy recovered by regenerative braking could in principle exceed the amount spent hauling the empty trains up. Peridotite isn't particularly common on mountaintops, because it's a mantle mineral that's exposed when sections of oceanic lithosphere (ophiolites) get uplifted onto continental crust. But the rocks on mountaintops are mostly silicates. My suggestion for increasing silicate weathering is to distribute puffed rock (stuff like expanded perlite and vermiculite) for soil improvement wherever the combination of soil improvement and carbon credits would make it profitable.
On Feb 4, 8:38 am, "Alvia Gaskill" <[email protected]> wrote: > I haven't listened to this yet and will provide comments later as needed. 54 > minutes, audio only. > > http://www.edie.net/news/news_story.asp?id=15949&channel=0&title=Biof... > > Biofuels 'need to be optimised' to succeed > Biofuels do have a part to play in the switch to a more sustainable transport > system but the production and supply chain needs to be refined to get the > most out of them. > > That was the opinion of Dr Steve Koonin, chief scientist at BP, as he spoke > at the Intelligence Squared Green Festival 2009, in London. > > Dr Koonin said much more work was needed to research which plants should be > used and in which way, how they could be grown more efficiently, and what > kind of fuels could be produced from them. > > "What we need to do to biofuels is to optimise the value chain," he said. > > "The petroleum value chain has been in existence for about 150 years - it has > been optimised and refined at the 1% level. The agricultural value chain has > been developed over several thousand years. > > "Right now we are doing biofuels by piggybacking it on the agricultural value > chain. That's a rather inefficient and technologically backwards way to be > tackling this problem." > > Dr Koonin's comments were part of a debate on biofuels with Nick Goodall, > chief executive of the Renewable Fuels Agency and Dr Ben Graziano, research > and development manager at the Carbon Trust. > > Listen to their comments in full below. > > Later in the day, it was the turn of geoengineering to be put under the > spotlight as experts discussed whether these often wacky solutions are a > silver bullet for the climate change crisis. > > Listen below to Professor Chris Rapley, director of the Science Museum in > London, and Professor Stephen Salter, of the University of Edinburgh, debate > the pros and cons. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
