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Comment by andyjsong | Hacker News Reader

Carbon sequestration is promising, but still years away. We need to start looking at stop gap solutions that buy us more time.

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Two of the biggest (non industrial) CO2 emitters are heating and transportation.

One of the lowest hanging fruits would be reducing CO2 emitting car use, using a massive capital expenditure to enable lower emitting public transit and cycling to enable people to drive less.

It's endlessly frustrating that even those polices, where are relatively cheap in the grand scheme of things are apparently too impossible for our political leadership.

We can reforest vast swaths of land right now. For instance, most of the US east of the Mississippi.

That can happen with tax code changes and land trusts.

We don't need to wait for new tech to scale up. We need to prioritize the planet.

We can't stop climate change by making it profitable. That's literally what got us into this mess in the first place.

If economic forces are powerful enough to cause climate change it seems reasonable to use another economic force to revert/cancel that out.

The economic forces that caused it were based on resource extraction.

Resource extraction is the core of our economy. Its why the US has vested interests in countries that have natural resources, and why the US is so quick to act when resources are nationalized.

We can either directly use taxpayer money to fund these initiatives and give them priority over things like starting wars and playing world police, or pay private individuals and ask very nicely that they help.

I much rather that national approach as I don't think middle men sapping a fat percentage is a great solution.

Its essentially a protection racket at the end of the day.

You can't always fight fire with fire though

I think that's the only way we can stop it.

If we make reducing emissions profitable our existing system will do it.

The other alternative is to completely rebuild our political/social system around something other than profit. Good luck with that, that's a fools errand.

Roughly half (even in the US!) our current system is built around something other than profit - i.e. the government directed part of the economy.

When you put it like that it sounds really difficult, but what exactly would it mean to "completely rebuild"?

IMO it could look something like this:

- Governments around the world set up a Climate Change Council

- The council is given power to regulate industry, and assign national resources

- High impact industry is shut down or refactored. For example, coal should be banned, but oil companies should be nationalized and fazed out while alternatives are built

That's pretty much it. It's hard, and it's a large effort over a long period of time, but there's nothing impossible about it. We don't have to reimagine society to do it.

Yes, more trees, but still not enough, here is a handy guide on the different solutions and consequences: https://www.roadto10gigatons.com/

Carbon sequestration is trivial: we rewild destroyed ecosystems. We don't need to die waiting for Elon.

I await my downvotes.

If we planted trees on every square meter outside of current cities (and let them grow without disturbing them), would that make a dent in carbon sequestration?

Serious question. Planting trees and re-growing ecosystems seems like a simple, straightforward solution, but I feel like it's a red herring.

My understanding is it would help quite a lot, and would also not be sufficient by itself to solve the problem.

Too many people jump from "it's not sufficient" to "therefore, we shouldn't do it".

Afforestation pretty much linearly absorbs carbon based on the size of the area you cover with trees, as a percentage of current forest area.

So if we doubled the size and carbon trapping of all the forests on earth, yes, it would make a big dent (solve the problem entirely, maybe). But that's unrealistic, because forests currently cover 30% of the land area of the planet, so we're practically never going to get to 60% forest coverage. It would involve giving up important things like farming.

It's not entirely a red herring, it will undoubtedly be a big part of climate change mitigation, but the first and most important step is to stop pumping oil out of the ground and burning it, like the article.

There's something you've missed there: forests - not just trees but the forest's understory, the animals living in it, the microbes in the soil etc - sequester carbon constantly. It isn't just "how much does the tree weigh, we've sequestered that much", it is about the ecological processes involved.

To give a fairly obvious example, think about deciduous trees: once a year they shed a large amount of carbon (leaves) which then goes into the soil. The nitrogen content is used for matter for plants, while the carbon is not.

Over time, this deposits more and more carbon in the ground itself. This is a good, safe place for it, and the model above is one of the simplest. Ecosystems are great at this stuff if we stop setting them on fire or otherwise killing everything.

Agreed on keeping it in the ground, though.

Well, the studies I was summarizing basically take that into account. The raw tree mass itself is both a) not that big and b) renewed, as you say, by decomposition.

Really the purpose of forests is more in terms of soil creation and preservation, as you point out, a lot of the times in the form of shrubs, leaves, or needles and downed wood being infiltrated into substrate.

The city where I live is considering a tree ordinance, driven by some local NIMBYs. I did some rough numbers based on things I found around the internet and:

One year of carbon sequestration from a mature tree == 1 or 2 days of commuting to the city 20 miles away that many people who are priced out of this town drive back and forth from.

Trees are great, and most places should plant more street trees. But if you preserve trees at the cost of building dense cities that are more environmentally friendly, you're doing it wrong. Dense cities also allow for more trees in actual wild lands outside of them, rather than sprawl.

In the US, transportation and heating are our biggest individual contributions to climate change.

There is no single silver bullet, but if you combine tree planting with nuclear / renewable power with remote work with electric vehicles ... eventually it starts to add up.

Shooting down solutions because they aren't the entire solution will mean we never make any progress.

Sure; I wasn't saying don't plant trees (street trees provide all kinds of benefits: https://www.strongtowns.org/journal/tag/street+trees ), just that transportation and how we build our cities are so critical. I did not realize the huge, orders of magnitude disconnect between exactly how much CO2 driving puts out and trees sequester.

In other unfortunate news:

https://www.cnbc.com/2023/04/25/gm-bolt-ev-production-to-end...

GM ending production of the Chevy Bolt in favor of bigger, heavier, deadlier, less efficient EV's.

Replace EVs with mass transit, and you've got something there. Density as an important component in reducing consumption doesn't end at the apartment building/Nplex lobby. Walking and cycling infrastructure also reduces health costs. Do you want to help curtail the oncoming Medicare crisis? Make Boomers bike.

That... seems obvious. Why do you assume the person you're responding to is proposing we increase sprawl? Increase density, increase public transit, and rewild outlying areas. It all goes together.

I was just stating some stuff. I was pretty surprised by just how much CO2 cars put out compared to what trees store.

Maybe mandate twice as thick wooden frames - that would capture more carbon in the house walls, and also conserve heating, as wood is a good insulator?

> Current studies suggest that mangroves and coastal wetlands annually sequester carbon at a rate ten times greater than mature tropical forests. They also store three to five times more carbon per equivalent area than tropical forests.

https://oceanservice.noaa.gov/ecosystems/coastal-blue-carbon...

It’s just not enough. Fossil fuels represent millions of years of the stored output of fully wild ecosystems. Rewilding the Earth today only gets us to the starting line to repeat that process.

Just "Reduce conversion of natural ecosystems" is the second biggest GHG impact, after solar and just above wind (though at a slightly higher cost), according to the IPCC:

https://www.ipcc.ch/report/ar6/syr/downloads/figures/summary...

Reforesting, afforesting and ecosystem restoration are nearly as impactful, but listed seperately.

Sequestration only starts making sense when we have basically unlimited green energy to throw at it. I know some moments have excess green energy already but you're not going to build a huge plant and run it only 2 hours a day.

The amount of natural resources needed to build enough plants to make it more than a drop in the bucket is also going to require significant mining operations and other big polluters. It's a nice idea but science fiction for now, at least at a scale that is actually effective at countering climate change.

And even if we had unlimited energy and materials the inertia of greenhouse emissions (the CO2 heating us now was emitted decades ago) building it at scale will come too late to avert a crisis.

It's still much easier and more efficient to avoid emitting the carbon we still do than to try and capture it back. Though even that will come too late really.

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