To put this in perspective, the global annual oil production is about 1 cubic mile [1], and concrete production is about half a cubic mile [2], [3] (4.4 BN tons at 2.4 t/m3 = 1.83 cubic km = 0.44 cubic miles)
[1]https://en.m.wikipedia.org/wiki/Cubic_mile_of_oil
[2]https://archpaper.com/2019/01/concrete-production-eight-perc...
The best science from the IPCC suggests we have to cut net carbon emissions by 50% by 2030 in order to have a moderate chance of avoiding the most catastrophic effects of the climate disaster.
I'm not saying 10% isn't ambitious, but it's entirely insufficient to the scope of the problem.
The IPCCs primary goal is to reduce carbon output, not figure out a way to enable it to continue. We have renewable and sustainable power technologies ready to reduce carbon output rapidly as soon as the political will to proceed is won.
This potentially huge mining scheme involves releasing what is in simple terms very large amounts of a pollutant into the Ocean. Its anticipated that the effects of this particular pollution will be beneficial, but we have no natural history to show for its ecological effects. Forests are already a great part of our worlds natural history.
I think it is a worthwhile scheme to begin implementing and observing the effects on Ocean ecology and also on the global mining industry which it has potential to stimulate. But the 100% target is an oversell in my view.
How so? What difference is there between emitting zero and emitting x kilograms and sequestering x kilograms?
Olivine rock: 10-25$/ton Crude oil: $60/barrel, so about $400/ton
Their website reads that "A volume of 7 cubic miles (11 km^3) of olivine, or around 30 Gigatons, is needed each year. This is less than half the volume of construction materials and less than that of fossil fuel equivalents mined yearly".
If olivine rock needs to be mined in comparable amount to fossil fuels to offset global CO2 production, it will cost about 5% of the fossil fuels, i.e., the price of oil will grow by about 5% globally, which is not much.
They think the conversion factor between cubic miles and cubic km is the same as between miles and km? Hm ....
They underestimated the volume of olivine rock about 3 times, which means that its mining would cost about 15% of the overall cost of mining of fossil fuels, assuming current prices of olivine rock and crude oil. This is a very rough estimate that doesn't take into account several factors, most importantly economy of scale.
In terms of construction materials, these 2009 calculations give 2005 numbers of over 60 Gt...
Growth in global materials use, GDP and population during the 20th century - http://www.vegetal-e.com/fichiers/2009-krausmann-al_14696916...
2014 number I found would be 1.3 cubic miles.
So take the numbers with a grain of salt.
https://www.newsmax.com/t/newsmax/article/627842?section=US&...