Live data from Hacker News

Planting trees not always an effective way of binding carbon dioxide

gu.se

61–70 of 153 posts

Re: Planting trees not always an effective way of binding carbon dioxide

#61

Yes you need to build ecosystems not just plant trees. Monoculture tree stands are often mostly empty of other life. You need to plant a variety of native species keeping track of keystone species and year round food production so that your forest supports other life.

Why do you care about the forest supporting other life? Isn't the goal just to take carbon out of the atmosphere?

Re: Planting trees not always an effective way of binding carbon dioxide

#62

So having read the article summary, then the research paper, then reading the article summary again... it seems that the summary isn't at all an accurate summary of the research paper, but rather a narrow focus on the suboptimal cases where tree growing isn't super effective at sequestering carbon. It sort of completely ignores the cases where they observed enhanced carbon sequestration, increases in soil organic car…

hm not sure but I think at high growth rates the majority of soil N does come from decomposition even when nitrogen fixation is present.

Re: Planting trees not always an effective way of binding carbon dioxide

#64

Earlier quoted context omitted.

While it's a good point that plant sequestration of CO2 is slow compared to digging up coal, oil or methane and burning it, it's not meaningless.

The point is, plant matter is not geologically sequestrated in the present world. The oceans are oxygenated and circulation is pretty strong, and permafrost is decreasing, not increasing. Hence, any photosynthesized carbon material will be returned to the atmosphere as CO2 relatively quickly. The only way to sequester carbon is to make something like limestone (Ca/Mg + CO2 + H2O -> (Ca/Mg)CO3) and that requires calci…

Why can't you just create oil or coal or similar products?

Re: Planting trees not always an effective way of binding carbon dioxide

#65

A redwood tree can live for more than 2000 years. That seems plenty long for carbon sequestration. We should pay the logging companies to save a certain number of trees instead of cutting them every 30 or so years.

When the trees are logged for use as lumber, the carbon is sequestered into structures and new trees are typically planted (or allowed to grow) for future logging, capturing carbon in the meantime.

Re: Planting trees not always an effective way of binding carbon dioxide

#66
post #39

I recently looked up the difference in CO2 emissions between burning 1kg wood vs 1kg petrol. Surprisingly, the values are relatively close: Burning 1kg wood releases 1.65 - 1.8 kg of CO2. [0] Burning 1kg of crude oil releases 3.16 kg of CO2. [1][2] I would have expected the carbon density of oil to be much higher! To me, this suggests that a very naïve approach of growing trees and storing them in the places where we…

Oil doesn’t come from huge caverns that we could drop trees into. Oil is often deep underground, soaked into porous rock. So wood would have to be liquified before attempting to pump it into oil wells, and it ruins the well for future use.

Wood is valuable and other plant material is similar carbon/kg, so the low-hanging fruit is to take agricultural waste (currently burned or left to rot) and bury it. Hauling all that straw around burns a lot of fuel, so it’s not clear how well it scales compared to other approaches.

Re: Planting trees not always an effective way of binding carbon dioxide

#67
Planting monocultures of trees is probably not ideal for plenty of reasons. Maybe there is some argument for re-wilding, allowing land to return to its natural (or as natural as it can given the proliferation of non-native species in the adjacent area).

Re: Planting trees not always an effective way of binding carbon dioxide

#69
post #65

A redwood tree can live for more than 2000 years. That seems plenty long for carbon sequestration. We should pay the logging companies to save a certain number of trees instead of cutting them every 30 or so years.

When the trees are logged for use as lumber, the carbon is sequestered into structures and new trees are typically planted (or allowed to grow) for future logging, capturing carbon in the meantime.

Good point!

I wonder if a 1000 year old tree would gather more or less carbon over it's lifetime than 20 separate 50 year old trees?

Re: Planting trees not always an effective way of binding carbon dioxide

#70

A redwood tree can live for more than 2000 years. That seems plenty long for carbon sequestration. We should pay the logging companies to save a certain number of trees instead of cutting them every 30 or so years.

Giant Sequoias need forrest fires to reproduce. Their pine cones won't open without sufficient heat. This makes sense, if you consider the dense forests these trees create.
Post reply on HN