Hacker News Reader

Comment by smakk | Hacker News Reader

Do you know if there are any current technologies to trap and sequester green house gases ?

One technology is called “TREES”, actually scratch that a more advanced version is called “RAINFOREST” (that one sequesters far more CO2 per square meter than TREES alone). Unfortunately people have cut down a significant portion of both TREES and RAINFOREST because they are economically incentivized to do so.

JFYI this "tree" technology of which you speak, can only be deployed at the earth's surface. AFAICT, OP was asking about upper atmosphere, which doesn't mix much with the lower atmosphere. Perhaps trees plus some way to mix the atmosphere?

Also, I believe we were talking about methane - and while these nifty "tree" things appear to sequester CO2, I believe these produce some amount of methane. Again, perhaps pair Trees(tm) with something to address the methane? For example, I've heard about "fire" but unsure if it can be deployed in the upper atmosphere, requires unrealistic concentrations of methane, or whether its outputs and side effects are acceptable.

:-)

The thing missing from upper atmosphere that destroys methane is water. Unfortunately, it's a greenhouse gas too, and relatively long-lived there too.

It's very likely best to focus in CO2 and let CH4 follow its short lived natural course.

Along with all the other carbon sinks we've drained, developed or heated to start emitting - peat bogs, wetlands, mangroves, permafrost etc.

Mature forests are at best net carbon neutral, and at worst net carbon emitters. Comparing our current emissions with amount sequestered per hectare of forest immediately gives that we don’t have nearly enough suitable unused land to plant new forests to make up for our current emissions. The only viable way to use forests to sequester carbon is to cut down immense numbers of trees and bury them underground. I don’t see anyone going to seriously propose this.

Actually, I wonder if that is true.

https://today.oregonstate.edu/archives/2008/sep/old-growth-f...

I'm sure tree-farmers would sale their trees to governments interested in sequestering carbon. Probably could just dump them in the oceanic trenches...

Clearly, if government is going to buy the lumber at market prices, the owners of the forests won’t complain or ask the purpose. However, the rest of us who would pay for the scheme would see the idea of burying the trees in order to offset the carbon we keep digging up as quite ridiculous.

If there were no alternatives to fossil fuels it wouldn't be ridiculous. Its just an offset (though, honestly, I suspect not an optimal one--carbon is not the only environmental concern we have, and mono-cultured tree farms are probably not a solution to those.. But we do have alternatives. In fact, I think that fossil fuels are preciously energy dense, that they should be kept in reserve for when truly needed. Let renewables be the solution for every-day needs.

one way to effect that directly is to eat less beef, I wonder how many are willing to make that sacrifice?

Besides planting trees as others have mentioned, there's Project Vesta [1], iron fertilization [2], and a few smaller-scale projects aiming to convert greenhouse gases back into liquids that could be stored, although most of the pitches promote them for being reused as fuel, ex. [3].

[1] https://projectvesta.org/

[2] https://en.wikipedia.org/wiki/Iron_fertilization

[3] https://carbonengineering.com/

Trees mostly. Algae has huge potential due to high growth rates. Mechanical or chemical sequestration is unlikely to do anything.

Some form of sequestration is necessary, because if you consider climate as a sinking ship, trees and algae are just sponges. They sequester some carbon for a while, and then release when decaying or burning. So fighting climate change with trees needs to involve cutting them down and storing them somewhere where they won't decay for thousands of years.

As far as I know, the most cost-effective method is very low tech--just find a good area and plant a variety of native trees.

The biggest problem I see is that you now have to protect those trees for basically forever. Fires will only become more problematic, and the push for more usable land as well. Also, trees take decades to grow, which we don't have.

Better than nothing yes, but not enough.

Reply on news.ycombinator.com