13 Misconceptions About Global Warming

Summary

This script discusses the nuances of climate change, addressing misconceptions about global warming. It clarifies that climate change encompasses more than just temperature increases, including extreme weather events, ocean acidification, and rising sea levels. The conversation refutes arguments that the Earth is not warming, highlighting the overwhelming scientific consensus and evidence from various indicators. It also explains the role of human-emitted CO2 in climate change, the feedback loop with water vapor, and the potential consequences of inaction, emphasizing the importance of reducing emissions.

Takeaways

• 🌍 The term 'climate change' is more encompassing than 'global warming', indicating a range of effects including storms, droughts, floods, and ocean acidification.
• ❄️ Despite occasional cold snaps, the overall trend shows an increase in global temperatures, with 13 of the 14 hottest years occurring this century.
• 📈 The debate over whether the Earth is warming or cooling is resolved by considering comprehensive data, including satellite information, which supports the warming trend.
• 🌡️ The 1970s saw a mix of scientific papers predicting both warming and cooling, but the majority and subsequent research have pointed towards warming.
• 🌊 Sea levels are rising, indicating that oceans are warming and expanding, which is a sign of global warming.
• ⛷ The melting of ice in Antarctica, Greenland, and the Arctic, along with the decline in Arctic sea ice, are further signs of a warming planet.
• 🌞 While the sun's brightness has fluctuated, its dimming since the 1950s hasn't halted the rise in global temperatures.
• 🌿 Human emissions of CO2, though a small fraction of the natural release, have upset the natural balance, leading to a significant increase in atmospheric CO2 levels.
• 🔬 The isotopic signature of CO2 indicates that the increase in atmospheric CO2 is likely from human activities, such as burning fossil fuels.
• 🌋 Contrary to popular belief, human emissions of CO2 far exceed those from volcanic activity.
• 🔁 The increase in CO2 and water vapor creates a positive feedback loop, amplifying the warming effect and potentially leading to significant temperature rises.

Q & A

What is the difference between 'Global Warming' and 'Climate Change'?

Global Warming refers to the long-term increase in Earth's average surface temperature, while Climate Change encompasses a broader range of effects, including more intense storms, droughts, floods, ocean acidification, and not just warming temperatures.

Why do some people confuse the terms 'Global Warming' and 'Climate Change'?

People might confuse the terms because 'Global Warming' suggests a consistent increase in temperature everywhere, which is not the case. 'Climate Change' is a more accurate term as it includes a variety of changes in weather patterns and not just temperature increases.

How does the presence of satellite data affect the understanding of global temperature trends?

Including satellite data in climate analysis provides a more comprehensive view of global temperature trends, as it covers areas that may not be adequately represented by ground-based measurements alone. This helps to confirm the overall warming trend.

What are some of the indicators that the Earth is warming, aside from temperature measurements?

Aside from temperature measurements, indicators of Earth's warming include rising sea levels, melting ice in Antarctica and Greenland, and a decline in Arctic sea ice.

Why do some people attribute climate change to the sun's brightness?

Some people attribute climate change to the sun's brightness because solar activity can influence Earth's climate. However, since the 1950s, while the sun's brightness has slightly decreased, Earth's temperatures have continued to rise, indicating that other factors, such as human activities, are the primary cause of current warming.

How do natural CO2 emissions compare to human emissions, and why is the balance important?

Natural processes emit about 780 gigatonnes of CO2 annually, compared to human emissions of about 30 gigatonnes. The balance is important because historically, natural processes absorbed as much CO2 as was emitted, maintaining stable atmospheric levels. Human activities have disrupted this balance, leading to a rise in atmospheric CO2 levels.

What is the significance of the isotope carbon-13 in understanding the source of atmospheric CO2?

Carbon-13 is less common in fossil fuels than in the atmosphere. A decrease in carbon-13 concentrations in the atmosphere indicates that the CO2 increase is likely from burning fossil fuels, as these emissions are richer in carbon-12.

Why do some people argue that volcanic emissions are a major source of CO2, and what is the actual comparison?

Some people argue that volcanic emissions are a major source of CO2 because they are visible and dramatic. However, human emissions are significantly higher, with humans emitting about 0.25 gigatonnes annually compared to less than one percent of that from volcanoes.

How does the presence of water vapor in the atmosphere relate to the greenhouse effect and CO2 emissions?

Water vapor is a potent greenhouse gas, and as the atmosphere warms due to increased CO2, it can hold more water vapor, which in turn amplifies the warming effect. This creates a positive feedback loop that contributes to further temperature increases.

What is the significance of Milankovitch cycles in the context of past climate changes, and how do they relate to CO2 levels?

Milankovitch cycles are long-term variations in Earth's orbit and tilt that affect the amount and distribution of solar energy received by the Earth, causing regular climate changes. During these cycles, CO2 levels and temperatures often rise together, but the initial warming is caused by the cycles, with CO2 increases amplifying the warming through a positive feedback loop.

What are the potential consequences of not addressing climate change, and why is early action important?

Potential consequences of not addressing climate change include more intense storms, droughts, floods, ocean acidification, and rising sea levels. Early action is important because it can help mitigate these impacts and is likely to be more cost-effective than dealing with the consequences later.

Outlines

00:00

🌍 Climate Change vs. Global Warming

This paragraph discusses the difference between climate change and global warming. It clarifies that while the average global temperature is increasing, leading to the term 'global warming,' climate change is a more encompassing term that includes a range of effects such as more intense storms, droughts, floods, and ocean acidification. The conversation also addresses common misconceptions, such as the belief that a cold day disproves global warming, and the confusion surrounding the term 'climate change' after a period of relatively stable temperatures. The paragraph emphasizes that climate change is not just about warming temperatures but also about the broader impacts on the environment.

05:01

🌡️ Debunking Misconceptions About Global Warming

The second paragraph delves into the scientific evidence supporting global warming. It counters the argument that the Earth is not warming by presenting data showing that thirteen of the fourteen hottest years occurred in the 21st century. The discussion includes the importance of including satellite data in climate analysis and addresses the fluctuation in Arctic sea ice as part of a broader trend of decline. The paragraph also explores the role of the sun in climate change, explaining that while the sun was brighter in the 1930s, its dimming since the 1950s has not halted the rise in global temperatures. The conversation concludes with a discussion on the impact of human-produced CO2, the balance between natural emissions and absorption, and the role of water vapor as a greenhouse gas, all contributing to the warming of the planet.

Keywords

💡Climate Change

Climate change refers to long-term shifts in temperatures and weather patterns. It is not just about the Earth getting warmer but encompasses a range of severe weather events, including more intense storms, droughts, and floods. In the script, the term is used to correct the misconception that global warming is the only consequence of increased temperatures, highlighting that climate change is a broader issue affecting ecosystems and human activities.

💡Global Warming

Global warming is the long-term increase in Earth's average surface temperature due to human activities, primarily the emission of greenhouse gases. The script addresses the confusion between 'global warming' and 'climate change,' emphasizing that while global warming is technically correct, climate change is a more comprehensive term that includes the wide-ranging effects of a warming planet.

💡Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth's surface. Certain gases in the atmosphere, like carbon dioxide and water vapor, trap heat from the sun, preventing it from escaping back into space. The script discusses how an increase in greenhouse gases, particularly CO2, intensifies this effect, leading to global warming and climate change.

💡Sea Level Rise

Sea level rise is the increase in the height of the Earth's oceans, primarily caused by the melting of ice sheets and glaciers and the thermal expansion of seawater as it warms. In the script, sea level rise is mentioned as evidence of global warming, as warmer oceans expand, contributing to the rise in sea levels.

💡Ice Melting

Ice melting refers to the process where ice, including glaciers and polar ice caps, turns into water due to rising temperatures. The script points out that ice in Antarctica and Greenland is melting at unprecedented rates, which is a direct consequence of global warming and contributes to sea level rise.

💡Arctic Sea Ice

Arctic sea ice is the frozen seawater covering the Arctic Ocean. The script discusses the decline in Arctic sea ice as a key indicator of climate change, with a specific mention of a temporary increase followed by a general downward trend, illustrating the volatility and long-term decline in this critical climate indicator.

💡Carbon Dioxide (CO2)

Carbon dioxide is a greenhouse gas that traps heat in the Earth's atmosphere. The script emphasizes the role of human-emitted CO2 as a significant driver of climate change, contrasting it with natural CO2 emissions and explaining how human activities have upset the natural balance, leading to a rise in atmospheric CO2 levels.

💡Carbon-13 Isotope

Carbon-13 is a stable isotope of carbon that is less common in fossil fuels than in the atmosphere. The script uses the decreasing concentration of carbon-13 in the atmosphere as evidence that the CO2 increase is from human activities, such as burning fossil fuels, rather than natural processes.

💡Volcanoes

Volcanoes are vents in the Earth's crust through which molten rock, ash, and gases are expelled. The script addresses the misconception that volcanoes are a major source of CO2 emissions compared to human activities, clarifying that human emissions far exceed those from volcanic activity.

💡Water Vapor

Water vapor is the gaseous state of water and is the most potent greenhouse gas. The script explains that while water vapor is indeed a powerful greenhouse gas, its concentration in the atmosphere increases with temperature, which is driven by the increase in CO2 levels, thus reinforcing the role of CO2 in climate change.

💡Positive Feedback Loop

A positive feedback loop is a process that occurs in a system that results in an increase in the output, which in turn causes an increase in the input, leading to further increases in the output. In the context of the script, the warming caused by CO2 leads to more water vapor in the atmosphere and melting ice, which in turn leads to more warming, creating a self-reinforcing cycle that amplifies the initial warming effect.

Highlights

The term 'climate change' is used to describe a broader range of environmental shifts beyond just temperature increases.

Global warming is technically correct as the overall average temperature of the planet is increasing.

Climate change encompasses phenomena like more intense storms, droughts, floods, and ocean acidification.

Thirteen of the fourteen hottest years on record have occurred this century.

Satellite data, when included, supports the ongoing upward trend in global temperatures.

Sea levels are rising, indicating that oceans are warming and expanding.

Antarctic and Greenland ice is melting at unprecedented rates.

Arctic sea ice is in a general decline, despite short-term increases.

The sun's brightness has not been the primary driver of recent warming; it has been dimming since the 1950s.

Human emissions of CO2 are a significant factor in climate change, despite being a small fraction of the total CO2 released.

The balance of CO2 in the atmosphere has been disrupted, leading to a rise in CO2 levels from 280 to 400 parts per million.

The isotope carbon-13 is less common in fossil fuels, indicating that the increase in atmospheric CO2 is from human activities.

Volcanic CO2 emissions are significantly less than those from human activities.

Water vapor, a potent greenhouse gas, is increasing in the atmosphere due to warming, creating a positive feedback loop.

Climate models have shown remarkable agreement with actual observations when adjusted for current understanding of climate sensitivity.

Past climate changes were triggered by Milankovitch cycles, not by CO2 emissions.

CO2 acts as a positive feedback in the climate system, amplifying the initial warming from Milankovitch cycles.

The consequences of not addressing climate change include more intense weather events, ocean acidification, and rising sea levels.

Reducing emissions now could mitigate future consequences and be more cost-effective.

Transcripts

Let's talk about the science of climate change. Don't you mean Global Warming?

How'd you get in here? I'm the Internet, I never left. Now why'd

you change the name? Global warming wasn't happening so you had to call it "Climate Change"?

The overall average temperature of the planet is increasing so Global Warming is technically

correct, but that doesn't mean it's going to be warmer everywhere all the time.

And that leads to some confusion, like on a cold winter's day, you might say...

So much for global warming! Exactly.

So the term climate change indicates that the problem is more intense storms, droughts

and floods, ocean acidification, not just that the globe is warming.

But it's not. What?

The globe's not warming. Since when?

1995 Um, that's not how you draw a trendline through

data. If the slope is nil, the climate's chill.

Y'know thirteen of the fourteen hottest years occurred this century and the graph you're

using is old, it doesn't include satellite data. If you take that into a count, the trend

is obviously continuing upwards. Oh, so now you say it's warming. In the past

scientists told us it was cooling. Why can't they just admit that they have no idea what's

going on? It's true in the 1970's there were some papers

published predicting cooling, but over that same time period there were six times as many

papers predicting warming. So scientists really haven't changed their tune.

Well just judging by temperatures, I say they're wrong. The Earth is cooling.

But you don't just have to go by temperatures. There are plenty of other signs that the globe

is warming, like sea levels are rising three millimetres a year. That's an indication that

the oceans are getting warmer and so are expanding. Ice on Antarctica and Greenland is melting

at unprecedented rates and arctic sea ice continues to decline.

Nuh-uh. Arctic sea ice increased forty percent in the last two years.

That last little uptick? That's what you focus on? What about the general downward trend?

It could mean anything. You know if the Earth is warming the most likely source of the problem

is the sun. The sun is getting brighter. Did you ever think of that?

The sun was getting brighter, in the 1930's, and it probably contributed to some warming

then. But since the 50's the sun has been getting dimmer and temperatures continue to

rise. Oh, so you automatically assume it's man-made

CO2. You know humans only emit a tiny fraction

of the CO2 released into the atmosphere every year.

That's true. People emit about 30 gigatonnes compared with 780 gigatonnes from natural

land and ocean processes. So you admit it, humans aren't the problem.

No! Before us the system was in balance with the land and oceans absorbing that same amount

- 780 gigatonnes a year. This balance kept the carbon dioxide levels

in the atmosphere between 180 and 280 part per million for 800,000 years. Now it's at

400 parts per million and still rising. But our small contribution couldn't have caused

that. Well the amount of CO2 in the atmosphere is

increasing by about fifteen gigatonnes or two parts per million every year.

But how do you know that's man-made CO2? Because the isotope carbon-13 is less common

in fossil fuels than it is naturally in the atmosphere. And over time we're seeing the

concentrations of carbon-13 are decreasing. But volcanoes emit way more CO2 than humans.

No they don't. They emit about 0.25 gigatonnes annually. That's less than one percent as

much as humans. OK, well even if we are responsible for the

rise in CO2, it doesn't matter because water is by far the most potent greenhouse gas.

Yes it is. I win.

No you don't! Water in the atmosphere is increasing as well.

But that can't be due to human activity. The only way for the atmosphere to hold more

water vapour is if it gets warmer. So... Hang on, you're not saying...

Yes! It all comes back to CO2. A doubling of CO2 on its own would increase the temperature

of the globe by one degree Celsius. But that warming means there will be more water vapour

in the atmosphere and ice will melt reducing the reflectivity of Earth's surface. So it's

a positive feedback loop, which a bunch of different sources of evidence all indicate

will lead to about a 3 degree Celsius rise in temperature.

But if this is true, why have all the predictions failed. In actuality most of the predictions

show remarkable agreement with observations. But you're probably thinking of the model

from 1988, back when we thought climate sensitivity was higher. If you re-run that model with

3 degrees of warming for every doubling of CO2, the predictions match exactly the warming

that we've observed. But the Earth has warmed and cooled in the

past. So who was releasing CO2 then, aliens? We understand that past changes in the climate

were triggered at regular intervals by Milankovitch cycles, that is the periodic oscillation of

the Earth's tilt, precession of the tilt, and stretching and squishing of Earth's elliptical

orbit. During every warming cycle, CO2 and temperature

rise together. Ah, but if you look closely at that graph,

you'll see that CO2 lags behind the temperature rise, so it can't be causing the warming.

The CO2 doesn't cause the first warming. The Milankovitch cycles change the way the sunlight

hits the Earth and that causes a little bit of warming decreasing the solubility of CO2

in the oceans. So some of that CO2 is released and that is a positive feedback loop, which

amplifies the warming. In fact over 90% of the increase happens after the CO2 starts

to rise. Let's say you're right, and the CO2 we're

releasing is warming the planet. What's so bad about that? The planet gets a little warmer,

big deal. I'm not claiming it's going to be some sort

of crazy catastrophe, but we are going to get more intense storms, more droughts and

floods, the oceans will become more acidic, sea levels will rise and my point is it would

be better for all species on this planet and probably cheaper for us if we just started

reducing emissions now than if we wait and pay the consequences later.

No thanks. Why are you wearing sunglasses?

Global warming. This episode of Veritasium was supported by

Audible.com a leading provider of audiobooks with over 150,000 titles in all areas of literature

including fiction, non-fiction, and periodicals. This week I wanted to recommend the book Merchants

of Doubt, which is about scientists who have spread misinformation about certain topics

like how cigarettes cause lung cancer, or how CFC's cause the ozone hole, or now how

CO2 is causing the planet to warm. So if you want to find out more about that you can download

this book by going to audible.com/veritasium or you can pick any other book of your choosing

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you for watching.