What biological life forms are as good if not better at absorbing CO2 than trees

[Wesley_Clark]

A big deal was made of how planting a trillion trees could counteract 25 years of climate change.

Planting a trillion trees could be the "most effective solution" to climate...

According to a new study in the journal Science, planting billions of trees around the world would be the cheapest and most effective way to tackle the climate crisis. Since trees absorb carbon dioxide, which contributes to global warming, a worldwide planting initiative could remove a substantial portion of heat-trapping emissions from the atmosphere.

The researchers say a program at this scale could remove about two-thirds of the carbon dioxide (CO2) emissions caused by human activities since the start of the industrial revolution, or nearly 25% of the CO2 in the atmosphere.

A tree can absorb about 50 pounds of CO2 a year, or a ton of CO2 within the first 40 years of its life. So a trillion trees = a trillion tons of CO2. The world produces around 36 billion tons of CO2 a year right now, so thats pretty impressive that something that may only cost a few hundred billion dollars could do so much to counteract climate change.

But what I’m wondering is, what other forms of life can absorb CO2, possibly cheaper and better?

I know seeding the oceans with iron has been looked at, since it can cause plankton to grow.

Iron fertilization

Also wouldn’t a faster growing plant like bamboo be a better choice? Bamboo doesn’t take 40 years to reach maturity, it can grow several feet each day.

I have no idea if this is true, but it says 1 square km of bamboo can absorb 25,000 tons of carbon.

How many carbon credits can be produced by 1 square km of bamboo?

In 2013, Tracy Li wrote a terrific article on this subject. Essentially, 1 km2 of Moso bamboo (a giant variety in China) can store about 25,000 tons of carbon per year; which is around 25,000 credits. See her article below:

I’m assuming that is 25,000 tons of Carbon dioxide and not just carbon (as that would be almost 4x heavier).

But if you assume that means 25,000 tons per year per square km that is a million tons over 40 years. I’m guessing that is more than a square km of trees would absorb over 40 years.

On another board I heard someone mention certain kinds of grass are better at carbon sequesteration than trees. Not just because they are faster growing and absorb more CO2, but because they store the CO2 underground.

I also heard someone claim that certain kinds of seaweed are very fast growing and can absorb a lot of CO2 faster (and possibly cheaper) than planting trees.

But you run into the question of what do you do with the carbon afterwards. Trees will eventually decompose but it’ll take a century. Bamboo will decompose faster. The grass supposedly traps it below the ground. I’ve heard the plankton will sink to the bottom of the ocean and take the carbon with it, no idea if it’ll decompose and increase the oceans acidity. I have no idea what happens to the seaweed carbon.

[Ethilrist]

The problem with planting something to sequester CO2 is that you need something to do with it once it’s grown so you can plant some more. The world can use a lot of wood. How much bamboo do we need?

[Wesley_Clark]

@Ethilrist

The problem with planting something to sequester CO2 is that you need something to do with it once it’s grown so you can plant some more. The world can use a lot of wood. How much bamboo do we need?

We can use bamboo for a variety of purposes, but we could also just grind it up and bury it.

[DSeid]

Bamboo does notactually perform well.

Replacing trees with bamboos halves the carbon storage capacity of forests

Mechanisms explained in link.

Meanwhile coastal ecosystems perform well. And oceans’ ability to sequester are restricted by the impacts of climate change.

The carbon sequestration potential of tidal salt marshes, mangroves, seagrass meadows, and kelp forests combined “compares favorably with and, in some respects, may exceed the potential of carbon sinks on land,” according to the International Union for the Conservation of Nature (IUCN), in a report released on Tuesday.

“If you look at the quality of carbon, compared to forests, you will find these habitats are 15 times more effective per unit area,” said Dan Laffoley, vice chair of IUCN’s World Commission on Protected Areas and an author of the report. “This has been a big wake-up call.”

The United Nations estimated in a report released in October that 3-7 percent of current fossil-fuel emissions could be offset in two decades if more action is taken to prevent marine vegetation loss and degradation worldwide.

The oceans are by far the largest carbon sink in the world. Some 93 percent of carbon dioxide is stored in algae, vegetation, and coral under the sea.
But oceans are not able to absorb all of the carbon dioxide released from the burning of fossil fuels. In fact, a recent study suggests that the oceans have absorbed a smaller proportion of fossil-fuel emissions, nearly 10 percent less, since 2000.

The study, published in the current issue of Nature, is the first to quantify the perceived trend that oceans are becoming less efficient carbon sinks.

The study team, led by Columbia University oceanographer Samar Khatiwala, measured the amount of human-caused carbon dioxide emissions pumped into the oceans since 1765.

“Our method takes as input the relatively well-known atmospheric CO2 concentration history. Given this history, we calculate the ocean absorption of industrial CO2 consistent with this history,” Khatiwala said.

Industrial carbon dioxide emissions have increased dramatically since the 1950s, and oceans have until recently been able to absorb the greater amounts of emissions. Sometime after 2000, however, the rise in emissions and the oceans’ carbon uptake decoupled. Oceans continue to absorb more carbon, but the pace appears to have slowed.

The reason is based in part on simple chemistry. Increased concentrations of carbon dioxide have turned waters more acidic, especially nearer to the poles. While carbon dioxide dissolves more readily in cold, dense seawater, these waters are less capable of sequestering the gas as the ocean becomes more acidic. The study revealed that the Southern Ocean, near Antarctica, absorbs about 40 percent of the carbon in oceans.

“There are several factors that may be responsible for what’s going on,” Khatiwala said. “Increasing acidity is only one of them. Faster emission growth rate is another, perhaps more important, cause, as could be changes in ocean temperature and circulation.”

[scr4]

@Wesley_Clark

I’m assuming that is 25,000 tons of Carbon dioxide and not just carbon (as that would be almost 4x heavier).

It specifically says carbon. And later in the article it says one hectare absorbs 250 tons which is the “… amount of carbon that was produced in 2009 by around 160 people in China,” which is consistent with 250 tons of carbon, not CO2.

But worldwide CO2 emission from fossil fuels is about 38 gigatons per year. So if I did my math right, we’d need to plant 1.5 million square kilometers of bamboo every year to absorb it all. That’s about twice the area of Texas.

[beowulff]

@Wesley_Clark

We can use bamboo for a variety of purposes, but we could also just grind it up and bury it.

That only kicks the can down the road.
What do you think happens to that buried wood?

[Reply]

Wikipedia actually has good overviews:

Carbon sink

Carbon sequestration

Broadly, you can combine forests, wetlands (inland and coastal), oceans, kelp forests, artificial underground storage, grasslands, etc. But it isn’t enough to just look at the CO2/square area or per dollar, etc. because major land use changes at a planetary scale means major economic and political chaos. The world’s forests, wetlands, etc. are not equitably distributed, and some of the best places for forests are also some of the most impoverished, and forcing ranchers or loggers to reconvert their rangelands into forests means that you’re just setting the stage for a future rebellion, and then they’ll just burn it all down again and re-release it into the air.

The difficulty isn’t just in calculating the best storage options upfront, but the idea of “permanence”: how likely, and for how long, a carbon sink will remain undisturbed (as opposed to being logged again, or dying of wildfire, or insect damage): https://theredddesk.org/markets-standards/design-features/permanence-reversals

[Reply]

Since you mentioned seaweed, ocean and wetland carbon sinks are together known as blue carbon:

Blue carbon

Different species and carbon pathways have different levels of permanence:
https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2018.0236

One group thinks kelp may offer good long-storage potential, basically by floating around until they sink into deep sea canyons and lie there undisturbed for a long time:
https://carboninstitute.org/kelp-and-carbon-sequestration-bringing-terrestrial-carbon-accounting-to-the-deep-sea/

[Rayks_Marcial]

I won’t be answering the OP question but a faster way of trapping carbon than growing anything is to grind/chop all our garden trimmings and uneaten food substances and dump them into the black swamp areas. This way you accelerate the formation of black muck which is carbon gel en route to becoming coal.

[Machine_Elf]

@beowulff

That only kicks the can down the road.
What do you think happens to that buried wood?

It takes a very long time to decompose. In fact, in the very long run, one might expect a fair portion of it to become coal (which we may then elect NOT to use as a combustible fuel).

@Wesley Clark

So a trillion trees = a trillion tons of CO2.

:dubious:

Let’s assume a mature tree is 20 feet across, which means it covers 314 ft[sup]2[/sup] of ground. A trillion such trees would cover 314,000,000,000,000 ft[sup]2[/sup] of ground. That’s 11.3 million square miles.

The total land area of the earth is 57.3 million square miles. 33% of that is desert, 10% is Antarctica, 8% is arctic tundra, and 37% is already being used for agriculture.

That leaves about 6.9 million square miles of land, a good bit of which is probably not conducive to a thriving arboretum because of human development or other conditions.

Do you see a problem here?

[kanicbird]

One shot in the dark would be a biofuel producing algae. Great if we can figure it out on a commercial level. It wouldn’t be so much as a carbon sink, but more like a way of getting off of fossil fuels, thus not adding more.

[Wesley_Clark]

@Machine_Elf

Let’s assume a mature tree is 20 feet across, which means it covers 314 ft[sup]2[/sup] of ground. A trillion such trees would cover 314,000,000,000,000 ft[sup]2[/sup] of ground. That’s 11.3 million square miles.

The total land area of the earth is 57.3 million square miles. 33% of that is desert, 10% is Antarctica, 8% is arctic tundra, and 37% is already being used for agriculture.

That leaves about 6.9 million square miles of land, a good bit of which is probably not conducive to a thriving arboretum because of human development or other conditions.

Do you see a problem here?

https://www.wthr.com/article/best-way-fight-climate-change-plant-1-trillion-trees

And there’s enough room, Swiss scientists say. Even with existing cities and farmland, there’s enough space for new trees to cover 3.5 million square miles (9 million square kilometers), they reported in Thursday’s journal Science. That area is roughly the size of the United States.

The study calculated that over the decades, those new trees could suck up nearly 830 billion tons (750 billion metric tons) of heat-trapping carbon dioxide from the atmosphere. That’s about as much carbon pollution as humans have spewed in the past 25 years.

Apparently there is free land to do so.

[Wesley_Clark]

@kanicbird

One shot in the dark would be a biofuel producing algae. Great if we can figure it out on a commercial level. It wouldn’t be so much as a carbon sink, but more like a way of getting off of fossil fuels, thus not adding more.

Yeah, scientists have been working on this for years.

The best method by far is to switch over to carbon neutral energy. But if we’ve already put too much CO2 out there we can use carbon sinks until we transition to a carbon neutral economy, or we can use them to reduce the amount of greenhouse gases to prevent the worst temperature increases.

[Wesley_Clark]

@beowulff

That only kicks the can down the road.
What do you think happens to that buried wood?

Its not a permanent solution, but it’ll buy time until we find better solutions.

If we can use vegetation as a carbon sink while we transition to cheaper forms of renewable energy, that is good. In a hundred years the trees may be cut down, and hopefully they’ll have better solutions by then.

[Gatopescado]

Hey! I’m doing my part! I plant trees by the butt-load. But its hard to get stuff to grow where I live.

@Ethilrist

The problem with planting something to sequester CO2 is that you need something to do with it once it’s grown so you can plant some more.

No problem! Just burn it!

[begbert2]

We just need to figure out how to make rockets out of wood and shoot them into space.

[Sunny_Daze]

At a high level, this seems like a solution that would make a material difference. Is anyone/any country actually working on this?

[beowulff]

@Machine_Elf

It takes a very long time to decompose. In fact, in the very long run, one might expect a fair portion of it to become coal (which we may then elect NOT to use as a combustible fuel).

:dubious:

Let’s assume a mature tree is 20 feet across, which means it covers 314 ft[sup]2[/sup] of ground. A trillion such trees would cover 314,000,000,000,000 ft[sup]2[/sup] of ground. That’s 11.3 million square miles.

The total land area of the earth is 57.3 million square miles. 33% of that is desert, 10% is Antarctica, 8% is arctic tundra, and 37% is already being used for agriculture.

That leaves about 6.9 million square miles of land, a good bit of which is probably not conducive to a thriving arboretum because of human development or other conditions.

Do you see a problem here?

Actually, most wood decomposes in under 100 years, and the CO2 is returned to the atmosphere.

[HMS_Irruncible]

@Reply

One group thinks kelp may offer good long-storage potential, basically by floating around until they sink into deep sea canyons and lie there undisturbed for a long time:
https://carboninstitute.org/kelp-and-carbon-sequestration-bringing-terrestrial-carbon-accounting-to-the-deep-sea/

That’s what sounds intuitive to me. Maybe a genetically engineered kelp that forms large carbonate nodules that drop to the bottom of the sea. Or some kind of insanely fast-growing coral.

I guess first we need to figure out how to de-acidify the ocean though. How do we do that?

[PoppaSan]

@Sunny_Daze

At a high level, this seems like a solution that would make a material difference. Is anyone/any country actually working on this?

Reforestation /less desertification has its ownpositive climate change effects. Not just sinking the carbon into the ground.
Ethiopia

Ethiopia has a larger goal of planting 4 billion trees between May and October 2019.

Youtube reforestation search
Brazil, Tasmania,Australia, Senegal, and China has many greening and reforestation projects.