Unit 2: Stopping Climate Change

Summary

The transcript from 'Project Drawdown' discusses the urgent need to address climate change to ensure a prosperous and equitable future. It explains the concept of 'drawdown' as the point when greenhouse gas levels in the atmosphere begin to decrease, marking the reversal of climate change. The script delves into the science behind greenhouse gases, their sources, and the impact on global warming. It emphasizes the importance of reducing emissions to zero and enhancing natural carbon sinks to achieve drawdown. The presentation outlines a three-pronged approach: mitigating pollution, supporting nature's carbon cycle, and improving societal equality, all of which contribute to comprehensive climate solutions.

Takeaways

• 🌍 Climate change impacts everything from water and food to health and the economy, necessitating action for a better future.
• 📉 'Drawdown' is the point when greenhouse gas levels in the atmosphere stop increasing and start to decrease, signifying the reversal of climate change.
• 🌱 Greenhouse gases, both natural and anthropogenic, trap heat in the Earth's atmosphere, leading to global warming.
• 🔥 Burning fossil fuels is a major source of CO2, contributing to over 62% of the observed warming, but industrial processes and deforestation also play significant roles.
• 🐄 Methane emissions, significant for short-term climate change, primarily come from agriculture, particularly cattle, and the fossil fuel industry.
• 🌾 Nitrous oxide, another potent greenhouse gas, is largely released through agricultural practices like excessive use of fertilizers.
• 🧊 Fluorinated gases used in refrigeration and industrial processes are synthetic and have a substantial impact on climate change.
• 🚰 The 'bathtub' analogy illustrates how sources (emissions) and sinks (natural absorption) interact to determine atmospheric greenhouse gas levels.
• 🌳 To achieve drawdown, we must reduce emissions to zero and enhance natural carbon sinks, such as forests and oceans.
• 🌐 Addressing climate change involves three key strategies: reducing pollution, supporting natural carbon cycles, and improving societal equality and justice.

Q & A

What is the term 'drawdown' in the context of climate change?

Drawdown refers to the point in time when greenhouse gas levels in the atmosphere stop increasing and begin to decrease, marking the beginning of the reversal of climate change.

Why is addressing climate change essential for a better future?

Addressing climate change is essential because it is interconnected with various aspects of life such as water, food, air, health, security, and the economy. Failing to address it makes achieving a prosperous and equitable future more difficult.

What is Project Drawdown and what is its mission?

Project Drawdown is a leading resource for climate solutions that focuses on the science needed to address climate change and shares it with the world. Its mission is to facilitate the world reaching drawdown as quickly, safely, and equitably as possible.

What are the primary greenhouse gases contributing to climate change?

The primary greenhouse gases contributing to climate change include carbon dioxide (CO2), methane, nitrous oxide, and fluorinated gases. These gases trap heat in the Earth's atmosphere, leading to global warming.

How do human activities contribute to the increase of greenhouse gases?

Human activities contribute to the increase of greenhouse gases through burning fossil fuels, industrial processes like cement production, deforestation, agriculture (especially cattle farming), and the use of fluorinated gases in refrigerants and industrial processes.

What is the significance of the 1-degree Celsius increase in global temperature?

The 1-degree Celsius increase in global temperature is significant because it has already led to noticeable changes in climate patterns. For context, the last ice age was only 3 degrees colder, which resulted in a drastically different planet covered in ice.

How do different greenhouse gases vary in their heat-trapping abilities and atmospheric lifetimes?

Different greenhouse gases vary in their heat-trapping abilities and atmospheric lifetimes. For instance, methane is a potent heat-trapper but has a shorter lifetime in the atmosphere (10-20 years) compared to CO2, which can persist for centuries.

What is the role of sinks in managing greenhouse gas levels?

Sinks play a crucial role in managing greenhouse gas levels by absorbing and storing these gases, preventing them from accumulating in the atmosphere. Natural sinks include forests and oceans, which can pull carbon dioxide out of the atmosphere.

What are the three pillars of climate solutions according to Project Drawdown?

The three pillars of climate solutions according to Project Drawdown are reducing pollution to zero, supporting and enhancing natural carbon sinks, and improving societal equality, equity, and justice, which can have secondary climate benefits.

How does the balance between sources and sinks of greenhouse gases determine the future of our climate?

The balance between sources (emissions) and sinks (absorption and storage) of greenhouse gases determines the future of our climate by influencing whether the levels of these gases in the atmosphere increase or decrease, which in turn affects global temperatures and climate stability.

Outlines

00:00

🌱 Understanding Drawdown and Climate Change

The paragraph introduces the concept of 'drawdown' as a pivotal moment in the fight against climate change. It emphasizes the interconnectedness of climate with various aspects of life, such as water, food, health, and economy. The speaker works for 'Project Drawdown,' an organization dedicated to sharing climate solutions grounded in scientific knowledge. The term 'drawdown' is explained as the point when greenhouse gas levels in the atmosphere stop increasing and begin to decrease, marking the reversal of climate change. The paragraph also delves into the science behind greenhouse gases, their role in trapping heat, and the distinction between natural and anthropogenic greenhouse gases. It highlights the impact of human activities on the atmosphere and the urgency to address climate change to secure a sustainable future.

05:01

🔥 Sources of Greenhouse Gases and Their Impact

This paragraph delves into the sources of greenhouse gases, particularly focusing on the enhanced greenhouse effect caused by human activities. It compares the natural greenhouse effect to the intensified one due to additional gases, likening it to adding an extra blanket for warmth. The discussion covers the significant contribution of burning fossil fuels to CO2 emissions, which accounts for approximately 62% of global warming. Other sources include industrial processes, deforestation, and agriculture, which emit CO2 and methane, a potent greenhouse gas. The paragraph also touches on lesser-known gases like nitrous oxide and fluorinated gases, which are significant due to their high heat-trapping capacity and long atmospheric lifetimes. The speaker quantifies the annual emission of greenhouse gases and stresses the need to reduce these emissions to mitigate climate change.

10:06

💧 The Balance of Greenhouse Gases: Sources and Sinks

The paragraph uses the bathtub analogy to explain the balance between sources and sinks of greenhouse gases in the atmosphere. Sources are activities that emit greenhouse gases, while sinks are natural processes that remove them. The current imbalance, with sources exceeding sinks, leads to a buildup of greenhouse gases. The speaker suggests that by reducing emissions and enhancing natural sinks, it's possible to achieve 'drawdown,' where greenhouse gas levels stabilize and then decline. The discussion highlights the importance of addressing both human-induced sources and natural processes that can help mitigate climate change. The paragraph concludes by emphasizing the need to work on reducing pollution, supporting natural carbon sinks, and improving societal structures to achieve a sustainable future.

15:08

🌐 Three Pillars of Climate Solutions

The final paragraph outlines the three key principles for addressing climate change: reducing pollution, supporting natural carbon sinks, and improving societal structures. It stresses the importance of stopping pollution at its source to prevent further atmospheric damage. The speaker also discusses the role of nature in sequestering carbon and the potential for enhancing these natural processes. Additionally, the paragraph introduces the concept of societal improvements that not only benefit humanity but also provide secondary climate benefits. The speaker concludes by stating that by focusing on these three pillars—reducing emissions, supporting nature, and improving society—we can effectively tackle climate change in the coming decades.

Keywords

💡Climate Change

Climate change refers to long-term shifts in temperatures and weather patterns, primarily caused by human activities such as burning fossil fuels and deforestation. In the video, it is the central issue that affects everything from water and food to health and the economy. The script emphasizes the urgency of addressing climate change to secure a better future.

💡Drawdown

Drawdown is the point in time when the concentration of greenhouse gases in the atmosphere stops increasing and begins to decrease, leading to the stabilization and reduction of these levels. The video discusses 'Project Drawdown' and its mission to reach this point as quickly and equitably as possible to reverse climate change.

💡Greenhouse Gases

Greenhouse gases are gases in the atmosphere that trap heat, leading to the warming of the Earth. The video explains that these gases, both natural and human-induced, have been increasing, causing global temperatures to rise. The script mentions carbon dioxide, methane, and nitrous oxide as key greenhouse gases.

💡Anthropogenic

Anthropogenic refers to human activities or processes that have a significant impact on the environment. In the context of the video, anthropogenic greenhouse gases are those resulting from human actions, such as burning fossil fuels and industrial processes, which contribute to climate change.

💡Carbon Dioxide (CO2)

Carbon dioxide is a greenhouse gas that is a byproduct of various human activities, including the burning of fossil fuels and deforestation. The video highlights that CO2 is a major contributor to global warming, with its levels having increased significantly due to human actions.

💡Methane

Methane is another potent greenhouse gas, with a greater heat-trapping capacity than CO2, though it remains in the atmosphere for a shorter period. The script points out that methane emissions come from agriculture, particularly from livestock, and the fossil fuel industry.

💡Nitrous Oxide

Nitrous oxide is a greenhouse gas that has a significant global warming potential. The video mentions that it is often overlooked but plays a substantial role in climate change, with agriculture being a major source of its emissions.

💡Fluorinated Gases

Fluorinated gases, such as chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs), are synthetic greenhouse gases used in refrigeration and industrial processes. The video notes that these gases, although less abundant, have a high global warming potential.

💡Sources and Sinks

In the context of climate science, sources refer to processes that release greenhouse gases into the atmosphere, while sinks are processes that remove them. The video uses the bathtub analogy to explain how reducing sources and enhancing sinks can help achieve drawdown.

💡Deforestation

Deforestation is the removal of trees from forests, which not only destroys habitats but also releases stored carbon into the atmosphere as CO2. The video discusses deforestation as a significant source of greenhouse gas emissions.

💡Renewable Energy

Although not explicitly mentioned in the script, renewable energy is a key concept related to the video's theme. It refers to energy sources like solar, wind, and hydropower that do not emit greenhouse gases and are essential for reducing CO2 emissions from electricity generation.

Highlights

Project Drawdown is focused on climate solutions and sharing the necessary science to address climate change.

The term 'drawdown' refers to the point in time when greenhouse gas levels in the atmosphere stop increasing and begin to decrease.

Greenhouse gases, including those naturally occurring and those caused by human activities, trap heat in the Earth's atmosphere.

Human activities have increased the levels of carbon dioxide, methane, nitrous oxide, and fluorinated gases in the atmosphere.

The enhanced greenhouse effect due to human activities is causing the Earth's surface to warm significantly.

Burning fossil fuels is responsible for approximately 62% of the warming observed on the planet today.

Industrial processes, such as cement production, also emit significant amounts of CO2 without combustion.

Deforestation contributes to CO2 emissions by releasing stored carbon back into the atmosphere.

Methane emissions are largely influenced by agriculture, particularly from cattle, and the fossil fuel industry.

Nitrous oxide emissions are linked to excessive use of fertilizers and manure in agriculture.

Fluorinated gases, used as refrigerants and insulators, are on the rise and are potent greenhouse gases.

The annual emission of greenhouse gases is approximately 52 gigatonnes of CO2 equivalent.

Each greenhouse gas has a different heat-trapping capacity and atmospheric lifetime, affecting their impact on climate change.

Methane's impact on short-term climate change is significant, causing about 32% of warming over the next 20 years.

The balance between sources (emissions) and sinks (removals) of greenhouse gases will determine the future climate.

To achieve drawdown, we must reduce emissions to zero and enhance the natural sinks' ability to remove CO2 from the atmosphere.

Three pillars of climate solutions include reducing pollution, supporting nature's carbon cycle, and improving societal equality and justice.

Transcripts

Okay, so now we're going to look at how we can stop climate change and achieve what we call "drawdown."

Stopping climate change is necessary if we want to have a better future, because everything we do is connected back to climate change.

Our water, our food, our air, our health, our security, our economy, are all connected to what happens to

weather and climate. So if we don't fix climate change, all the other things we care about in the future are going to be

a lot harder. So we need to address climate change in order to have a better future with a prosperous economy with

resilience, equity, justice, and creativity. All the things we want demand that we address climate change.

And that's what we're about. I work for something called

Project Drawdown, which is the world's leading resource for climate

solutions. We focus on the science we need to know to

address climate change and then share it with the world.

But why do we use that word "drawdown?" What does that even mean? Well, drawdown refers to a point in time, in the future, and

refers to the greenhouse gas levels in the atmosphere. Now, remember, I told you in the last unit, greenhouse gases have

been building up in the atmosphere. Here we are today at the 2020 levels. But then, we can choose what happens next.

On the path we're on now, we'll just continue to build up these gases – which will just warm the planet more, making the

problem worse. But we don't have to do that. We can bend the curve. Bending the curve on climate change means reversing

the curve of growing greenhouse gases. And when we hit this point, the little blue dot here, that's the moment of

drawdown. That's the moment when greenhouse gases stop climbing and they begin to go back down again into a

healthier place. So drawdown is the moment in the future when greenhouse gas levels stabilize and stop climbing,

and then they start to steadily decline. And that's when we begin to stop climate change. At Project Drawdown, our job

is to get the world to drawdown as quickly, safely, and equitably as possible. So how do we get there?

Well, first, we're going to have to learn a little bit of science. It won't be too hard, but it's the stuff we really do need to know to

kind of get forward on climate solutions. So first of all, what are greenhouse gases? We've heard a little bit about

this before, I'm sure. You know that greenhouse gases kind of let in the sun's heat, and they trap the Earth's heat as Earth

is radiating out into outer space. So essentially, they trap heat. And the more gases, means the more heat. And that's

why the planet’s warming up. Pretty simple. Now there's a little bit more to it. It turns out that Earth already had greenhouse

gases before we came along. There were natural greenhouse gases, like water vapor, a little bit of carbon dioxide, and

a few other things that have been there for millions, if not billions, of years of Earth history. But then we've got these

things we call "anthropogenic" greenhouse gases or human- caused greenhouse gases that we've been adding on top of that.

And those include more carbon dioxide than was there before, more methane, more nitrous oxide. We've added

chemicals that weren't even in the atmosphere before like fluorinated gases, so-called chlorofluorocarbons,

hydrofluorocarbons, and so on, and many other gases that are impacting our climate. And we can actually see how they've

been rising over the last 100, 200 years, and especially in the last few decades. We have changed the nature of Earth's

atmosphere and added a human greenhouse effect on top of natural greenhouse effect. And that's where we're getting into trouble.

So what do these do? It's actually really simple physics. The idea is, greenhouse gases are

transparent. They let solar radiation, visible light, what we can see, right through them, like just a window. You can

see right through it. But infrared radiation, which you and I can't see, it is opaque. The infrared radiation is what

Earth gives off to the rest of the universe. And so it can trap that heat in the atmosphere. It kind of works like this.

Imagine a version of Earth with no atmosphere at all, like the moon. It would absorb the sun's radiation and warm

up. The sun is heating the ground, and the ground would warm up. The ground, just obeying the laws of physics, would also

give off heat, or infrared radiation, back to the rest of the universe, out to outer space. And without an atmosphere, this

is what it would look like. The sun's heat comes in, Earth's heat goes out, and they'd be in perfect balance, and we would be at a

temperature that would be accordingly in balance with that. But now, let's add an atmosphere, a natural atmosphere. So we

have what was the natural greenhouse effect. The idea is as Earth is radiating its heat out into outer space, some of it

would be absorbed by the air above it, and some of that would then be re-radiated back down towards the Earth's surface.

That has the effect of making the Earth's surface a little bit warmer and the upper atmosphere a little bit colder.

And that's exactly what Earth has had and so are mainly all of the other planets.

Venus, Mars, and others also have a greenhouse effect kind of like that.

But then humans come along, and we add some more of those gases to the atmosphere. It would be like adding

another blanket on your bed in the wintertime. It traps more heat and keeps you toastier, a little bit warmer, and so on.

And so this enhanced greenhouse effect traps a little bit more heat,

radiates a little bit more down, and it warms the surface even more.

And so far, we've warmed the planet about one degree Celsius. That doesn't sound like a lot, but think

about it. During the last ice age, the planet as a whole was only 3 degrees colder than normal, and it was a totally

different planet. This place was under about a mile of ice, in fact. We've warmed the planet in the other direction by

about 1 degree so far, and we're going to keep going. If we keep going to another 2, 3, or 4 degrees, that

could be a world we wouldn't even recognize. It'd be very, very dangerous for our civilization.

So where do these gases come from?

Well, I'm sure you've already heard that a lot of them come from burning fossil fuels, right? Burning oil, and natural gas,

and coal, and petroleum, and substitutes, and all of these things that we have. And that is part of the story. Burning fossil

fuels does create CO2, and that causes about 62% of the

warming we see on the planet today. So if you forget about

everything else, fossil fuels cause more than half of climate change. But that's not all. It turns out that CO2 is

also produced by a few other things, including chemistry.

In fact, a lot of our industrial processes, especially making

cement, releases CO2 into the atmosphere without burning anything at all. It's just kind of industrial chemistry.

We also release a lot of CO2 into the atmosphere by

burning down trees and deforestation.

This green area shows you how much CO2 is caused by burning

down forest which is kind of like burning coal. Coal is dead. Trees

are alive, but they're both made out of carbon.

And you burn them in our atmosphere, you will make carbon dioxide either way.

Then we have our next greenhouse gas of methane.

Methane is produced by a whole bunch of different things,

but the two big sources are agriculture and industry. In agriculture, which is about two-thirds of this methane emissions, is

caused largely from cattle. And you've heard all the jokes before I'm sure about cow farts. Turns out that's not even

true. Cows actually burp methane. They don't fart methane any more than other animals.

The other third of this methane comes from

industry, especially mining natural gas, gas wells,

fracking, gas pipelines, even coal mines release methane as

well. So we have to think about energy and industry and agriculture to look at methane. Then we've got this stuff

called nitrous oxide which a lot of people don't even think

about, but it's a big part of our climate change equation.

Nitrous oxide, some of that comes from industry, but

again, a lot of it comes from agriculture, especially using

too much fertilizer or too much manure on our farmers' fields.

And finally, we have F-gases or fluorinated gases, which are chemicals

we use as refrigerants and sometimes as insulators in industrial processes.

And those refrigerants like chlorofluorocarbons and hydrofluorocarbons

are rising dramatically. And that's why we have to pay attention to those.

So putting all those gases together, we emit about 52 gigatonnes of the equivalent of carbon dioxide into the

atmosphere each year. What the heck is a gigatonne? It's just a fancy word for a billion metric tons. So we emit 52

billion metric tons of pollution into the atmosphere every year.

But there are only seven and a half billion of us.

So on average, we're emitting many, many tons of pollution per person into the atmosphere. That's a huge amount. But we're

going to talk more about that and how we can cut that down. Another thing we have to notice is that each of these gases

works a little bit differently. Some gases trap more heat than others. Like methane and nitrous oxide and those

fluorinated gases trap way more heat molecule for molecule than CO2 does. But some gases last longer in the atmosphere

than others, too. We’ve got to take that into account. Like methane we emit today, most of it will be gone within 10 to

20 years. CO2 we emit today will be in the air for centuries and centuries to come. So we have to look at the strength and

lifetime of these different gases. In particular, when we think about methane, methane, again, is that part of

the wedge of our whole diagram of greenhouse gases. If we look at the impact of today's emissions on climate for the

next hundred years, methane will cause about 16% of that warming over a hundred-year period. But if we look at the next 20 years

instead, the role of methane doubles and becomes 32%. So it turns out in the near term, our climate changes are going to

be caused by mainly methane and other gases. But in the long term, they're going to be dominated by things like CO2.

So which gas we focus on depends a little bit on what time period of climate change you're really most concerned about.

We have to look at all of them. Now that we understand what greenhouse gases are and kind of how they work, we're going

to look at what regulates the level of those gases in the atmosphere, what makes them go up and what makes them go

down. To do this, sometimes it's helpful to think of a bathtub.

But imagine a bathtub which we can fill and empty with water.

We do that every day, right? Pretty simple. When we add water to the

bathtub by turning on the faucet, we scientists call that

a source. It's a source of water, and it levels up the water in the bathtub.

We can also remove water by opening up the drain,

and scientists call that a sink. You'll hear that word a lot, about sinks of greenhouse gases. The difference

between the sources and the sinks determines whether the water goes up or the water goes down. Sources add and make

the water go up. Sinks remove and make the water go down. Now, if you have a bathtub with the faucet on and the drain open,

we have an interesting picture. If the sources are bigger than the sinks, the water level will still go up. But if the

drain, the sink, is bigger than the faucet, the source, the water levels will go back down again. So let's take that and

apply it to Earth's atmosphere. Well, Earth's atmosphere is

basically a big bathtub in the sky. We can fill it with

pollution and greenhouse gases, the sources of greenhouse

gases, which is largely due to us. And then we have sinks of

greenhouse gases, things that pull that pollution out of the

sky and put it someplace else. We have sinks on this planet

of greenhouse gases primarily in plants, on land, but also in the oceans.

So here's the picture. We put pollution in the atmosphere, nature

pulls it out, in forest and in oceans. Now right now, our sources of

pollution, the stuff we're putting in the atmosphere, is much bigger

than what nature can take out, and that's why the levels are going up.

But what if we reduced our pollution? What if we brought it down by a half or so?

Well then, maybe nature could kind of keep up with it

and pull as much pollution out of the atmosphere as we're putting in.

If that were to happen, we would hit that moment of drawdown,

and we'd stabilize CO2 levels, and they'd stay flat.

But we can go farther and actually reduce our pollution down to

zero, and pull more carbon and other stuff out of the atmosphere,

and actually have greenhouse gases decline and stop climate

change and begin to reverse in the long term, the damage we've done.

So this balance between sources and sinks is what will determine the future of our planet and our climate.

But let's look at the numbers.

In today's atmosphere, we see that we actually have about six major sources of greenhouse gas

pollution. We'll go into them later, but you see electricity, and food, industry, transportation, buildings, and other stuff.

Then we have nature, which on land and in oceans, pull out a total of

  about 41% of those greenhouse gases, primarily the carbon

dioxide part. And that leaves behind 59% of those greenhouse

gases in the atmosphere building up year over year, over year.

So to achieve drawdown, to get them to reverse and bend the curve back down, we've got to work on both sides of

this equation. We can work on the sources and bring them down

to zero, kind of turning off that faucet over the coming

decades, so there's no pollution there at all. And we can

also work with the sinks of carbon, starting with the

natural ones that already exist, and make sure they can

continue to pull that stuff out of the sky. So the idea of

getting to drawdown actually will be based on three big principles. And these are important. The first thing we've

got to do, and we always need to begin here, is reduce the problem before it even starts. Let's stop pollution before

it even gets in the atmosphere so it doesn't cause any problems at all. And that means bringing these emissions

down to zero. So we're going to have to zoom in and look at what causes these emissions, what's in the economy, what can

we do about it, in all of these different sectors, from electricity, to industry, to agriculture and beyond. And if we

do that, we can cause a big reduction in these things and eventually bring them down to zero.

So job number one, stop pollution. Bring it to zero.

Job number two, will be working over in

the nature space, basically supporting nature's carbon

cycle, and maybe even adding to it in the form of sinks.

That's the right-hand side of this diagram. We'll have to

zoom in here and look on land and oceans about what controls

their ability to take up carbon, and how can we support

that, and maybe even augment it, making it stronger in the

future. So we've looked at the left-hand side and the right-hand

side of that big picture, the sources, the sinks, and we know what to do. But there's a third area we've got to talk

about too, and we'll get into this later. It's about how, as we improve society, we can do things that aren't about

climate change. They are things we should do anyway. But when we improve the equality, and equity, and justice around the

world, there are things we do there that actually have major secondary climate benefits. So we might get a twofer of

improving human rights and equality and contributing to climate solutions. So working together, reducing pollution,

supporting nature,

and improving society are the three pillars of our climate solution space. Building in these three pillars and pulling

them together all at the same time, we actually have all we need to address climate change in the coming decades. And

this is going to be our job over the next few units of this course.