Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions • Hacker News Board

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#161

Post by slothtrop » Sun, Apr 21, 2019, 7:45 PM UTC

ed_balls wrote: post #114

ALittleLight wrote: post #97

Earlier quoted context omitted.

It seems incredibly practical to me. I've seen a quote for 40 dollars to plant a thousand trees. That's something like 50 billion to offset a decade of global warming? Doesn't sound so bad. Spread the cost out worldwide, 5 billion a year, split between a few big countries? http://forestandrange.org/southernpine/magement/planting/rea...

I don't think planting trees is the biggest issue. Access to water is. More practical solution would be to fill some desert with sea water and grow plankton, kelp etc.

Deforestation is one of the reasons some deserts have spread so rapidly. trees behave as a shield to that encroachment

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#162

Post by sametmax » Sun, Apr 21, 2019, 7:45 PM UTC

sooham wrote: post #159

At one tree per second It would take 38000 years to plant 1.2 trillion trees. This proposition is beyond our currently available resources.

At one carrot per second, you can't provide food for the entire human demand.

But we don't plant one carrot per second.

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#163

Post by bencollier49 » Sun, Apr 21, 2019, 7:46 PM UTC

If there are seven times more trees than previously thought, as per the article, and 1.2 trillion would have this effect, then what effect does that have on climate models which counted sequestration by trees?

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#164

Post by tbabb » Sun, Apr 21, 2019, 7:48 PM UTC

I wonder how increasing the forestation of the planet by 40% would affect the planet's average albedo, and by extension the solar thermal energy retention.

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#165

Post by SlowRobotAhead » Sun, Apr 21, 2019, 7:48 PM UTC

bencollier49 wrote: post #163

If there are seven times more trees than previously thought, as per the article, and 1.2 trillion would have this effect, then what effect does that have on climate models which counted sequestration by trees?

Likewise, is the water needed for 1.2 trillion trees calculated?

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#166

Post by noja » Sun, Apr 21, 2019, 7:49 PM UTC

We need to stop buying stuff we don't need, chucking food we didn't eat, and eating beef like there's no tomorrow.

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#167

Post by tbabb » Sun, Apr 21, 2019, 7:49 PM UTC

sooham wrote: post #159

At one tree per second It would take 38000 years to plant 1.2 trillion trees. This proposition is beyond our currently available resources.

I don't think that's the right metric for assessing feasibility. Humans can do more than one thing at the same time.

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#168

Post by bjourne » Sun, Apr 21, 2019, 7:50 PM UTC

dota_fanatic wrote: post #93

jandrese wrote: post #76

Earlier quoted context omitted.

That's only 160 trees for every man, woman, and child on Earth... It doesn't seem like a particularly practical solution.

How hard is it to plant a tree? Especially if it's young and there is very clear guidance as to which native trees should be planted in which contexts you have available to you locally (account for full size growth and sunlight / water needs). If over one year everyone planted 3 trees per week, and we employed a work force of people to cultivate them further, we would make a huge dent in our catastrophic risk exposur…

It is not difficult but doing it without the right machinery requires back-breaking labor. It looks like this: https://www.youtube.com/watch?v=uUzeruQT8xE I did it one full weekend and I was totally exhausted. Of course, there exists machines to do that, but then you can't have every person in the world chipping in.

But planting is just the first step. If you own a growing forest it needs to be culled periodically, meaning that you cut down the worst performing 10-20% of all trees.

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#169

Post by Radim » Sun, Apr 21, 2019, 7:51 PM UTC

CO₂ is a precious and much coveted resource in nature. It's predicted to become all sequestered under ground eventually, on a billion-year timescale (making it quite troublesome for life!).

More pressingly, when it comes to plant life RIGHT NOW, we're still dangerously close to CO₂ starvation levels. The current ~400 parts-per-million are a good deal healthier than the ~180 ppm we've had throughout Quaternary (which nearly killed off all plant life). But compared to ~4000 ppm during the Cambrian explosion, we're still in a dire CO₂ drought.

Interesting science tidbit: not all plant life is equipped to handle CO₂ equally well. To combat the "recent" CO₂ drought, some plants evolved a new photosynthesis pathway called C4 over the past ~5m years [0]. Only about 3% of flowering plant species use the C4 pathway (notably tropical grasslands), but these account for 23% of the carbon fixed (primary productivity) in the world.

OTOH, trees in the OP fall under the older "C3 pathway", which cannot make use of CO₂ nearly as efficiently, and as a consequence struggle the most in CO₂-impoverished climates [1].

[0] https://en.wikipedia.org/wiki/C4_carbon_fixation#The_evoluti...

[1] https://phys.org/news/2018-04-carbon-dioxide-boost-plantgrow...

Re: Planting 1.2T Trees Could Cancel Out a Decade of CO2 Emissions

#170

Post by jloughry » Sun, Apr 21, 2019, 7:53 PM UTC

This is one global-scale geoengineering project I can rally get behind. It has the smallest chance of catastrophic second-order effects of any of the several methods I've heard of.