Unit 4: Supporting Sinks and Improving Society

Summary

This script discusses combating climate change by enhancing natural carbon sinks like forests and oceans, which absorb over 40% of annual CO2 emissions. It emphasizes the need to protect these systems, suggests regenerative agriculture and potential technological solutions, and highlights societal improvements like gender equality and education that can indirectly benefit climate efforts.

Takeaways

• 🌳 Forests and oceans are the primary natural carbon sinks, absorbing over 40% of annual CO2 emissions.
• 🌊 Oceans, despite covering more of the Earth's surface, absorb less carbon than land due to their limited capacity.
• 🔥 Climate change is already affecting forests and oceans, threatening their ability to act as carbon sinks.
• 🌱 Supporting and protecting natural carbon sinks is crucial to address climate change.
• 🚫 Limiting human activities that harm these sinks, such as deforestation and overfishing, is essential.
• 🌿 Regenerative agriculture and reforestation can potentially increase carbon sequestration but have their limits.
• ⏱ The process of carbon absorption by natural sinks can be slow, often taking decades for full effect.
• 🌡️ Warming oceans reduce their capacity to absorb CO2, impacting the solubility pump mechanism.
• 🐚 The carbonate pump, involving shell-building marine life, is a significant but threatened carbon sequestration process.
• 🌱 The biological pump, through marine plants and phytoplankton, plays a role in carbon sequestration.
• 🔄 Improving societal factors like gender equality and education can have indirect benefits for climate change mitigation.

Q & A

What is the role of nature's carbon cycle in addressing climate change?

Nature's carbon cycle, particularly through forests and oceans, serves as a significant sink for greenhouse gases, absorbing over 40% of annual CO2 emissions. Supporting these natural sinks by ensuring their health is crucial for mitigating climate change.

Why are forests and oceans important in the context of climate change?

Forests and oceans are important because they absorb a substantial portion of the pollution we emit, primarily in the form of CO2. Forests, in particular, are highlighted as a significant factor in carbon sequestration.

What challenges are forests and oceans currently facing that could affect their ability to act as carbon sinks?

Forests are experiencing the impacts of climate change and are being deforested, while oceans are warming, becoming more acidic, and facing increased pollution and over-harvesting, which could diminish their capacity to absorb carbon.

What is the significance of the 59% of greenhouse gases that remain in the atmosphere after natural sinks' absorption?

The 59% of greenhouse gases that are not absorbed by natural sinks indicates that while nature plays a vital role, additional solutions are necessary to address the full scope of climate change.

Why is it important to support nature's existing carbon sinks before creating new ones?

Supporting existing carbon sinks is crucial because they already remove 40% of emissions naturally, and ensuring their preservation prevents the loss of this essential service.

What are the limitations of carbon sinks, and why should we be cautious about relying on them exclusively?

Carbon sinks have limits as they cannot absorb an infinite amount of greenhouse gases. For example, trees have a maximum size, and soils have a limited depth and carbon capacity. Therefore, it's more important to prevent emissions than to rely solely on sinks for removal.

How do the time lags associated with carbon sinks affect our ability to mitigate climate change?

The time it takes for sinks to absorb greenhouse gases, such as the hundred years it might take for trees to mature, introduces a time lag during which climate change continues to worsen, making it an insufficient immediate solution.

What are the differences between biological and geological carbon sinks, and which are more permanent?

Biological sinks, like trees and soil, can be reversed, such as through burning or farming practices, making them less permanent. Geological sinks, like carbon locked in rocks or coral reefs, are more permanent, as they can store carbon for much longer periods on human timescales.

How can we support and enhance land-based carbon sinks?

We can support land-based carbon sinks by reducing deforestation, improving agricultural practices, and adopting regenerative agriculture, which can help maintain and potentially increase the carbon sequestration capacity of the land.

What are the three major mechanisms by which oceans absorb carbon dioxide?

The oceans absorb carbon dioxide through the solubility pump (dissolving CO2 in water), the carbonate pump (living animals building shells), and the biological pump (photosynthesis by marine plants).

How can we potentially enhance ocean-based carbon sinks?

We can potentially enhance ocean-based carbon sinks by protecting coastal ecosystems, such as mangroves and wetlands, and exploring new methods like farming kelp or planting new coral reefs.

What is the potential of machines as carbon sinks, and how might they contribute to climate change mitigation?

Machines, particularly those that can pull carbon out of the atmosphere and store or utilize it, represent an emerging technology with the potential to become significant carbon sinks. They could help mitigate climate change by reducing atmospheric CO2 levels.

How can societal improvements, such as gender equality and access to education, indirectly contribute to climate change solutions?

Societal improvements can lead to a more educated and empowered population, which may result in lower birth rates and a more sustainable use of resources, indirectly contributing to climate change mitigation.

Outlines

00:00

🌳 Addressing Climate Change with Nature's Carbon Cycle

The paragraph discusses the importance of supporting natural carbon sinks like forests and oceans, which absorb over 40% of annual CO2 emissions. It emphasizes the need to maintain the health of these ecosystems, as they are crucial for combating climate change. However, it also points out the current challenges faced by these systems, such as deforestation and ocean pollution. The speaker suggests that while enhancing these natural sinks is part of the solution, it cannot be the sole approach, as 59% of greenhouse gases remain in the atmosphere. The paragraph introduces four key points to consider: the necessity of supporting nature's existing carbon removal capabilities, the limits of carbon sinks, the time lag involved in their absorption process, and the potential impermanence of some sinks.

05:01

🌱 Enhancing Land-Based Carbon Sinks

This paragraph delves into the role of land in absorbing CO2 through photosynthesis, biomass accumulation, and soil organic matter. It highlights the importance of preserving natural vegetation, particularly forests, and suggests measures such as avoiding deforestation and adopting regenerative agriculture to enhance carbon sequestration. The speaker also cautions about the limitations of these methods, noting that they are temporary and can be disrupted by events like fires or changes in land use. The paragraph emphasizes the need to balance the promotion of regenerative agriculture with other climate solutions and to focus on protecting ecosystems to maintain and enhance land-based carbon sinks.

10:08

🌊 Oceanic Carbon Sinks and Their Enhancement

The final paragraph focuses on the ocean's role in carbon sequestration, which absorbs 17% of greenhouse gas emissions through three main mechanisms: the solubility pump, the carbonate pump, and the biological pump. It discusses the challenges faced by these processes due to climate change, such as the reduced ability of warmer water to absorb CO2. The speaker suggests that protecting coastal ecosystems like mangroves and wetlands can help both as carbon sinks and in protecting coastlines from storms. Additionally, the paragraph explores the potential for creating new oceanic carbon sinks through aquaculture and coral reef restoration. It also touches on the emerging technology of machines that could directly remove carbon from the atmosphere, although these are still in early stages of development.

Keywords

💡Greenhouse gases

Greenhouse gases are gases in Earth's atmosphere that trap heat by absorbing and emitting infrared radiation. They are crucial for maintaining the planet's temperature but can cause global warming when their concentrations increase. In the video, it discusses how these gases are absorbed by natural sinks like forests and oceans, which are essential for mitigating climate change.

💡Carbon sinks

Carbon sinks refer to natural or artificial systems that absorb more carbon dioxide than they release, thus reducing the amount of this greenhouse gas in the atmosphere. The video emphasizes the importance of supporting and enhancing these sinks, such as forests and oceans, to combat climate change.

💡Photosynthesis

Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll pigments. It involves the conversion of carbon dioxide and water into glucose and oxygen. The video mentions that photosynthesis in plants, particularly trees, contributes to carbon sequestration.

💡Regenerative agriculture

Regenerative agriculture is a system of farming principles and practices that aim to improve soil health, sequester carbon, and support ecological balance. The script discusses how this method can potentially absorb carbon, although it has its limits and is not a complete solution to climate change.

💡Ocean acidification

Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide from the atmosphere. The video script points out that this process, along with warming and pollution, is harming the oceans' ability to act as a carbon sink.

💡Coral reefs

Coral reefs are underwater ecosystems or structures made from calcium carbonate secreted by corals. They provide habitats for many marine species and also act as carbon sinks. The video mentions that coral reefs are important for carbon sequestration but are threatened by climate change.

💡Food waste

Food waste refers to the discarding or spoilage of food, which contributes to greenhouse gas emissions, particularly methane from decomposing food in landfills. The video script discusses how reducing food waste can help preserve carbon sinks by reducing the need for additional food production.

💡Deforestation

Deforestation is the removal of trees and forests, which not only leads to habitat loss but also reduces the capacity of forests to act as carbon sinks. The video emphasizes the importance of protecting forests to maintain their role in climate change mitigation.

💡Carbon capture and storage (CCS)

Carbon capture and storage is a technology that captures carbon dioxide emissions from the air or directly from industrial sources and stores it underground to prevent it from entering the atmosphere. The video script suggests that machines capable of CCS could become an important part of the solution to climate change.

💡Climate adaptation

Climate adaptation refers to adjustments in natural or human systems in response to actual or expected climate stimuli or their effects, which moderates harm or exploits beneficial opportunities. The video script mentions how protecting coastal ecosystems like mangroves can help in both climate change mitigation and adaptation.

💡Emissions

Emissions refer to the release of pollutants or greenhouse gases into the atmosphere. The video script discusses the need to reduce emissions at the source, as this has an immediate effect on pollution levels, in contrast to carbon sinks which take time to absorb these emissions.

Highlights

Supporting nature's carbon cycle is crucial for addressing climate change.

Forests and oceans are currently absorbing over 40% of annual CO2 pollution.

The health of natural sinks like forests and oceans is deteriorating due to climate change and human activities.

The primary task is to support and maintain the health of existing natural sinks.

There's potential to augment natural sinks by managing land and ocean systems more effectively.

100% of emissions originate from human activities, with land and oceans mitigating a portion.

Land-based sinks, primarily forests, remove about 24% of greenhouse gases.

Oceanic sinks account for 17% of greenhouse gas absorption, despite covering more surface area.

About 59% of greenhouse gases remain in the atmosphere, indicating the need for comprehensive solutions.

Nature's 40% removal of greenhouse gases is significant and must be supported.

Sinks have limits and cannot absorb an infinite amount of greenhouse gases.

The time it takes for sinks to absorb greenhouse gases introduces a lag in climate change mitigation.

Biological sinks like forests and soil are not permanent and can be reversed.

Geological sinks may offer more permanent solutions for carbon storage.

Photosynthesis, biomass, and soil organic matter are key mechanisms for land-based carbon sinks.

Protecting ecosystems, reducing food waste, and changing agricultural practices can preserve and enhance land sinks.

Regenerative agriculture shows promise but has limitations and should be balanced with other solutions.

Oceans absorb CO2 through the solubility pump, carbonate pump, and biological pump.

Protecting coastal ecosystems like mangroves and wetlands can enhance carbon sinks and protect against storm surges.

Emerging technologies may enable machines to become carbon sinks by extracting CO2 from the atmosphere.

Improving societal factors like gender equality and access to education can indirectly benefit climate change mitigation.

Addressing climate change can have secondary benefits for society, aligning environmental solutions with social improvements.

Transcripts

Okay, so now we're going to talk about how we can address climate change by looking at the sinks of greenhouse gases,

and also how changes in society can have secondary benefits to climate change. As we think about these issues, one of

the best places to begin is supporting nature's carbon

cycle. These are things that are naturally sinks of

greenhouse gases today. If we zoom in here, we can see how

forests and oceans are absorbing over 40% of the pollution

we put in the atmosphere every year,

most of that in the form of CO2.

And so if we can support those sinks and make sure they stay healthy,

that would help us address climate change into the future. But the problem is, some of these

systems aren't that healthy right now. A lot of our forests are feeling the weight of climate change already or being

torn down. And our oceans are getting warmer and more acidic and they're also getting more polluted and over-harvested

at the same time. So job number one here is just

kind of support nature, give it some backup,

and make sure that it isn't diminishing the sinks we already have. Later, hopefully, we can augment those sinks by putting

other land and other ocean systems into production and add to what nature is doing already.

But here's the math we've got to start with: 100% of these emissions are coming from us.

Land is putting out about 24% or

removing it and putting it into our forests.

The oceans are pulling out about 17% of the greenhouse gases

and putting it into different parts of the ocean.

Interestingly, even though oceans cover a lot more of the Earth's surface, they actually take up less of the

carbon than the land does. Oceans are important, but forests are kind of a big story here. Altogether, that still leaves

about 59% of the greenhouse gases in the atmosphere. And so this is part of the solution, but it can't be the whole

solution. And before we look at the individual sinks, there are about four major points I think we have to talk about

before we even get started. First of all, it is crucial that we give nature support because nature is already doing 40%

of all the removal, and we're doing zip. So starting with backing up nature, giving it support, and making sure we

don't lose that service of removing greenhouse gases is crucial. Then once we kind of get that stuff secured, we can

also maybe add some of our own new carbon sinks by planting new trees or farming new areas in different ways, or maybe

machines that pull carbon out of the atmosphere, all of that. But first, why don't we help out in nature that's

doing a good job already.

The second thing to remember is sinks all have limits. They can't take an infinite amount of greenhouse gas out of the

atmosphere. There's no way. Trees only get so big. Soils only go so deep and can have so much carbon in them. Coral

reefs can only grow so fast. So we have things that have a limited capacity to absorb our greenhouse gases. That's why

it's probably more important to stop them before they ever get in the atmosphere than try to remove them later. And

that leads to a third point. Sinks take time to absorb greenhouse gases. If you put out a tonne of CO2 today and

plant trees to offset that, it might take a hundred years for those trees to grow fully to maturity, absorbing carbon out of

the atmosphere. But in the meantime, you've got a hundred years of climate change caused by the pollution you started with. So

you can't really get away with this by planting trees to offset emissions, introduces a time lag where climate change

is just going to be worse. There's kind of an asymmetry here. Turning off a power plant stops pollution today.

Planting trees or building coral reefs or whatever, basically is a solution for 50 to a hundred years from now.

The other thing we have to worry about is sinks may not always be permanent. They might not be secure. For example, some of

our sinks are biological in nature: growing a new tree, putting stuff in the soil, putting stuff in a kelp forest, or

whatever. Those are biological sinks, and they're great. But they can also be reversed. We can plant trees, and then they

could be burned down. We could farm really well and build up the soil, but that farmer retires, the next one comes in and

plows it all up, and it goes back in the atmosphere instantly. So these kind of biological sinks can sometimes

be quite ephemeral. They may not be permanent. But some sinks might be more geological in nature. If we can lock up

carbon in kind of like a rock or something like a coral reef or down in the basalt or something like that, then we've got

something that's locked up pretty much permanently, at least on human timescales.

So let's look at these sinks one by one. On land, again,

it takes up about a quarter of our emissions, which is

pretty amazing. And it's doing it with photosynthesis.

The natural vegetation of our planet, especially trees,

are growing a little bit faster now,

and they're accumulating more biomass, or essentially wood. And when those things die, they build up a little more carbon in

the soil, what we call soil organic matter.

So photosynthesis, biomass of the living stuff, and soil

organic matter. That's where all the carbon goes. And we can

help maintain those sinks in nature by leaving nature

alone. We can first take pressure off of nature by not

clearing forests, for example. And that's where food waste,

and diets, and things like that, where we don't need to grow more food and invade those forests because we're more

efficient with the food we already grow. That’ll be crucial.

But also putting up kind of big protections around the

remaining rainforest and peatland forest and other

ecosystems, to make sure they're never cleared at all.

And then, once we've kind of taken care of nature and secured it,

then we can do exciting things like putting our farmland

into new types of agriculture that might absorb carbon, what

we often call “regenerative agriculture.” So we looked at

these solutions. We looked at food waste and diets, not by just reducing emissions, but preserving sinks. We looked at how

protecting forests didn't just reduce the deforestation emissions, it kept the forest sinks intact, too.

And then we looked at how changing agriculture and degrading lands back into production and reversing that can be really

important as well. One of the things I want to mention though, is regenerative agriculture is getting a lot of

attention these days. This idea that farms and ranches could be farmed differently to absorb carbon. That is true.

There's a lot of great evidence showing that we can grow crops and livestock in ways that can actually absorb carbon,

whether in trees in the forested areas around the farmland, or in agroforestry, or in the soil itself. And

that's really exciting. But there are limits to how much this can happen. There's only so much soil they can build up.

There are only so many trees you can build up, and they are all kind of temporary. The next farmer or a drought or a

fire could disturb all of them, putting them back in the atmosphere. So be careful there. There's also a few groups

that are not really paying attention to the science, I would say, that are making big bold claims that regenerative

agriculture can absorb all of our greenhouse-gas pollution. That is just not true at all. The scientific community is

quite clear that it is a solution. But it's one of many solutions, so we've got to make sure we balance it with all

the others. So when we look at the numbers, we see that protecting ecosystems and reducing food waste kind of

protecting and taking the pressure off of ecosystems, is critical here to preserving sinks. And then we can put the

farmlands and the degraded lands into better systems of agriculture so they absorb carbon too. So this combination

of kind of taking pressure off of land, protecting it, and then farming our working lands in different ways can be powerful

ways to maintain and enhance land-based carbon sinks. The oceans are kind of different. We don't manage the oceans as

much as we might on land. A lot of it's out in the open ocean where we don't do so much. Coastal oceans are another

matter, though. But either way, oceans as a whole, even though they take 71% of the planet, absorb 17% of our

greenhouse gas emissions. And they do it through three major mechanisms. One is what we call a “solubility pump.” That's

just a fancy way of saying CO2 dissolves in water. And what's interesting here is that salt water dissolves CO2,

just like fresh water does. But as water warms up, it absorbs a little less CO2 than cold water. So as the climate

changes, we can't really expect the solubility pump to get bigger. It's probably going to stay where it is or maybe

go down a little. Then we have something called the “carbonate pump,” which is where living animals pull carbon

dioxide and calcium out of the seawater, and they use it to build a shell or shellfish. Things like oysters and clams

and mussels, but also crabs and lobsters. They pull that stuff out of the water and build shells that stay there for

quite a long time. Corals are the same thing, too. Remember, corals are animals. They're not plants. They're not rocks.

They are little polyp animals that build a calcium carbonate shell around them that we call a coral reef. And

that takes CO2 out of the water as well. And then we finally have the biological pump which is just basically the plants

in the ocean. The little tiny microscopic phytoplankton and diatoms that do photosynthesis, as well as what we call

“macrophytes,” or big plants, like kelp forests. They do photosynthesis. They build bigger plants and those plants

will later die and get buried in the ocean sediment. So all of those things, whether it's just chemistry, building

shells, or growing plants, pull carbon out of the air, through the water, and tuck it away. We can do a little bit to help

already, obviously. For example, protecting the coastal

ecosystems from being developed or torn apart. Like

mangroves and wetlands and marshes

are critical carbon sinks. But also, they're turning out to be really helpful in

protecting our storm surges on the coastline. When we have healthy mangroves and coral reefs and marshlands and wetlands

along the coast, we don't have as much flooding or as much damage from storms. So it kind of helps us prevent climate change

but also adapt the climate change that is already here.

That's a good win-win in my book. But we might also be

able to add new carbon sinks out in the ocean, maybe through

farming kelp in big regenerative aquaculture systems. Or

maybe planting new coral reefs in oyster beds and lots of other things. We're just beginning to explore the

possibilities here, and I think they're going to be really cool.

So we looked at land and oceans, but then we can look to

machines to maybe become carbon sinks. There are machines out there, kind of in laboratory settings, and a few very

small pilots. The atmosphere is not noticing these things at all yet. They're way too small.

But the idea here is maybe we could build machines

that would pull carbon out of the atmosphere and either store it down in the rock somewhere or

tuck it away and lock it up or use it for something. That's the one that gets me really excited. If we could pull

carbon out of the atmosphere as carbon dioxide or whatever and use it to make plastics or jet fuel or other things

society might want without using oil at all! Use pollution to make our stuff, not new oil. Leave the oil in the ground.

We'll take the old stuff out of the air. That would be really cool. This is nowhere near being deployable right

now, but some of these technologies are very interesting. And over the next 10 years or so I think we're going to see a

lot more rapid development of these technologies, and they may start to play an important role. So we've looked at the

carbon sinks and before that the carbon sources. And we can see by reducing pollution, working with nature, and maybe

augmenting nature, we've got a lot we can do about climate change. But there's a third principle too, that improving

society, not because of climate change, but because it's the right and moral thing to do, turns out to be a great set of

climate solutions. It's kind of interesting. And it turns out

improving equality and equity, especially with women and

girls, for example. Improving the access to education and

health care helps women and girls see new opportunities

around the world. And as a consequence, women and girls will have maybe fewer children but healthier children, a little

bit later in life, than they might have otherwise had. And when that's the case, the growth of population in the future

might bend down earlier than we thought before. While population growth actually isn't really responsible for most

of climate change – most of the emissions are from rich people, not poor people – future population growth slowing

down will actually help us a little bit in the long run as population growth and economic development drive up

emissions in the future. So this is a great win-win by helping women have new opportunities,

we might actually help the environment and the climate as well.

So it turns out that helping people for lots of good reasons

actually can help us with climate change as well.

And this represents kind of a win-win

opportunity to improve human well-being,

as well as improving our future climate solutions.