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I'm Dr. Peter Kelmus, I'm a climate scientist, and today I'll be answering questions from Twitter about our planet.
0:05
This is Earth Support.
0:11
At _Ruth the YY asks, "I'm so over this planet. Are there any planets out there we can live on yet? Because this, some bowl."
0:19
No, there are no planets out there that we can live on and that we can currently get to.
0:24
And Mars totally sucks.
0:26
It's cold, it's a desert, there's no water, you're bombarded by radiation that would give you cancer.
0:30
It's just basically a cold, awful hellscape of a planet.
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And I love this place, I love Earth, and I'm here for life.
0:38
Adam and J Panda asks, "Hurricane season starts June 1st, so do they just wait until that day or how does it work?"
0:44
Hurricanes are powered by hot ocean water, and you get hotter water in the summertime and in the fall, so that's why late summer, fall is the prime hurricane season.
1:01
At a B_LSOC asks, "How do satellites monitor the weather?"
1:01
Excellent question.
1:03
So, there are two main kinds of weather satellites.
1:09
You've got polar-orbiting satellites which stay in the same position relative to the sun as the Earth rotates underneath them, so they'll sample the planet two times per day: once in the daytime and then once in the night time, descending.
1:16
And then you also have geostationary satellites which are looking at the Earth and rotating along with Earth, so they're always seeing the same thing.
1:26
Then there are four main kinds of sensors on these satellites.
1:30
You've got optical imagers which can see clouds, how high the clouds are.
1:31
You have infrared and microwave sounders which together can give you information about how much moisture there is in the air columns from the surface of the planet all the way to the top of the atmosphere.
1:45
And then finally you have radars which can see rain and snow and other kinds of water that's falling from the clouds to the Earth.
1:51
Satellites are indispensable for studying the weather and the climate.
1:59
At Paul_McGuire asks, "Cloud physics, um, what me no understand Professor."
1:59
Yeah, so it is one of the most complicated parts of the Earth system, in my opinion, and I'm saying that as somebody who used to study cloud physics.
2:06
We understand them at multiple levels using different kinds of models.
2:10
If you're looking at them with a radar, you'll define it in one way.
2:14
If you're looking at it with optical imagery, you might define the edges of clouds another way.
2:17
You've got clouds of different layers.
2:19
The physics works both on the very smallest scales, the tiny water vapor particles and aerosols that can nucleate the clouds, to the very largest scales of atmospheric circulation and these, you know, huge weather patterns.
2:32
There's a whole universe of science just in clouds.
2:33
At MGS Science asks, "How do global winds and ocean currents work? How does density play a role?"
2:41
So, the ultimate driver of both the ocean currents and the air currents is the sun.
2:46
So the sun hits the equator, it's hotter at the equator, much colder at the poles.
2:51
Air goes up from the equator and it heads towards the poles and it comes down right around California or Spain.
2:58
So you have westerly winds in the subtropics and then in the equator you have the trade winds which are coming from the east and going to the west, and the same thing again, remember, is happening in the Southern Hemisphere, the opposite direction.
3:10
The ocean works in a similar way.
3:10
In the Atlantic, you have the Gulf Stream going up the coast of North America.
3:10
It gets colder as it gets closer to the poles.
3:10
Colder air is denser.
3:10
It gets saltier as some of that water on the surface freezes and that also makes it denser, and that denser water sinks down into the depths of the ocean and then goes along the ocean floor back towards the equator.
3:10
Melting water from the Greenland ice sheet by adding fresh water to the ocean water, the fresh water is less dense so it doesn't want to sink down and that could cause potentially that overturning circulation to change or maybe even to stop.
3:10
At Kevin Burke 14 asks, "What is polar amplification again?"
3:10
So very simply, when you have ice sheets covering the Arctic Ocean, they're white, they're very bright.
3:10
You look at them from space and they reflect a lot of sunlight.
3:10
When that ice melts and goes away, you're left with dark ocean water which absorbs a lot of sunlight, which makes the planet get even hotter and more ice melt.
3:10
At MGR Youth asks, "Why is climate change happening?"
3:10
Eighty percent of the global heating that we're experiencing on the planet today comes from burning fossil fuels, which are buried carbon, coal, oil, fossil gas that's locked under our ground.
4:25
We burn that stuff and each carbon atom combines with two atoms of oxygen from our atmosphere to make carbon dioxide, CO2.
4:31
The other 20% comes from methane, and this is another molecule created by animal agriculture, so cows breaking down grasses in their stomach and then burping out this methane and nitrous oxide which comes from fertilizer.
4:47
So this stuff in our air actually acts like a blanket and means that more energy from the sun is coming in than is escaping right now from space, and that makes our planet hotter.
4:56
At Vijay Gagara asks, "What is the difference between global warming and climate change?"
5:02
Global warming, I prefer the term global heating, and that is the whole planet getting hotter every year on average because of burning fossil fuels.
5:10
That planetary heat causes all of this chaotic change, which we could call climate change, the things like the fires and the flooding, the heat waves.
5:18
And I prefer the term climate breakdown because that's what it really feels like to me, where it's not just innocuous, innocent change, it's all kind of heading towards a world that's very different than the world we're used to and that our civilization is adapted to.
5:32
At Coffee Jelly 44 asks, "Why is the coral reef dying? Bad. Maybe Earth is on to bigger and better things."
5:40
I love coral reefs.
5:43
They're these crazy, colorful, alien animals that have solar panels embedded right in their flesh, and coral reefs are dying around the planet because of ocean heat waves.
5:59
So just like on land we're experiencing worse and worse heat waves as the planet gets hotter, ocean animals and plants are also experiencing worse and worse heat waves as the oceans heat up.
6:05
Scientists who study the fossil record have found that there have been five previous what we call mass extinctions on planet Earth, where you just have a huge dip in biodiversity because so many species die.
6:15
One of them was when the dinosaurs died when a giant asteroid hit the Earth.
6:20
We're in the sixth mass extinction right now, and a big part of that extinction pressure is the planet heating up because of burning fossil fuels.
6:28
And it's true that after about 10 million years, the biodiversity will recover from this, but there's a whole lot of death and suffering between now and 10 million years from now.
6:38
And I firmly believe that we should do everything we can right now to stop that death and suffering.
6:43
At USNA 73 asks, "Carbon cycle, explain please."
6:49
Carbon, this black atom with 12 protons and 12 electrons, the main component of coal and oil and fossil gas.
6:59
Our bodies are made out of it.
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It's in the atmosphere, it's in trees, it's in the food that we eat.
7:08
The food, it goes in our body, our body breaks the food down, turns it into energy, we breathe it out as carbon dioxide which goes into the atmosphere, goes into trees again, the cycle continues.
7:14
There are several reservoirs in the carbon cycle.
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You've got land plants, you've got fossil fuels, you've got the ocean which dissolves carbon into the water, and then you've got the atmosphere which is like the Grand Central Station that helps carbon move between these different reservoirs.
7:32
All of the transfer of carbon between these reservoirs was roughly in balance until quite recently when one species on this planet decided to dredge up huge amounts of fossil fuels, so carbon from that fossil fuel reservoir, burn it, and put it into the air reservoir, which is another way of understanding why the planet is heating up right now.
7:57
At Furetusa asks, "Just learned that NASA scientists were arrested for protesting about climate change and that climate change is so bad that we only have three years left to save our planet.
8:02
Why am I not seeing this more?"
8:04
Well, I know of one NASA climate scientist who got arrested protesting climate inaction, and that's this guy.
8:13
A lot more should do it though.
8:13
Now we do not have just three years to save the planet.
8:13
How it works is the longer we burn fossil fuels, the worse it will get.
8:13
This is a planet-wide emergency, but so far world leaders aren't acting like it, the media is not reporting like it.
8:13
We have to heat our homes, we have to get around on the surface of this planet, but we now have alternatives to do all that without fossil fuel industry.
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What we have to do is sever the influence of that industry over our politicians and our media so that we can actually implement these alternatives, and in my opinion, that's going to take a really strong grassroots movement, which is why I chose to engage in non-violent civil disobedience.
8:52
At A Tumulty asks, "When a climate alarmist says that AGW anthropogenic global warming is causing storms to become more violent, ask them what is the actual cause of this."
9:02
A hotter atmosphere holds more water.
9:07
That's basic physics.
9:11
Every degree centigrade that the atmosphere gets hotter is 7% more water, which is actually quite a lot, and that means stronger rainstorms, more flooding, more rain.
9:18
He goes on, "When they say that CO2 is causing the planet to heat up, ask them why does the satellite data show no net warming in 33 years?"
9:30
The satellite data absolutely, and all the other datasets by the way, absolutely show that the planet is heating up.
9:33
So this shows the global average surface temperature reconstruction from all the thermometers on the planet and proxies going back to 1880 to the present day, and it is a clear trend that should be flat, that should not be going up.
9:50
Now if you look at this next plot which shows the global ocean heat content, and 93% of the excess energy coming into our Earth is getting absorbed by the ocean, this is perhaps the fastest global heating the Earth has ever experienced.
9:48
At Pork Fried Spice asks, "How much longer until Florida is underwater? I've heard that very few property insurers dare to offer services there because of a problem dramatic climate forecasting."
10:27
So it depends on what part of Florida you're talking about.
10:27
The highest point in Florida is about 350 feet above sea level, but there are some parts of Florida and some of the most valuable parts like Miami Beach that are just a little bit above sea level.
10:27
They're already seeing what's called sunny day flooding, which is when there's a high tide, you get water in the streets, water in the buildings.
10:27
By 2300, we could expect between maybe 10 feet and 50 feet of sea level rise depending on how much of this CO2 we continue to emit, but there's huge uncertainties in those estimates.
10:27
It could be much worse than that.
10:46
It's going to keep getting worse after 2300.
10:47
At 40 Dargas asks, "How can air travel be decarbonized? Is there an alternative to fossil fuel to fly planes? Just wondering."
10:55
Not at this time.
10:57
We can fly planes with batteries, but they only go a couple hundred miles because you can't store enough energy in those batteries to lift it up on planes.
11:07
The batteries are just too heavy.
11:07
The batteries would have to improve about a factor of 10 in terms of their energy density in order to be useful for planes crossing oceans.
11:15
Another thing you hear about is biofuels, which is basically running the airplanes on vegetable oil, and that works, but there's simply not enough of it, so we can't run commercial aviation at its current scale without fossil fuels.
11:27
At PPH Norag asks, "I'm genuinely wondering what can I do to reduce climate change? Toodles."
11:32
This is a great question and I think of it in two categories.
11:36
So first is direct action, the second is what we call individual action.
11:40
Direct action is more important, and by this I mean get really noisy about how much you want world leaders to act on climate change, and when I say really noisy, I'm also talking about non-violent civil disobedience.
11:52
The second category is using less fossil fuels yourself.
11:54
The main thing I did was to end flying, so I haven't flown on a plane since 2012.
12:08
I don't want to get on a plane because it feels really gross to me knowing how much emissions that plane causes.
12:08
And at Logging On Web asks, "Realistically, is there any way we are going to reverse climate change? Like are there any inventions or solutions in the works to do this? Trying to find something positive in regards to the future of the planet."
12:08
Unfortunately, no, there is no way to reverse global heating.
12:08
Now there is one technology which I think has gotten overhyped called carbon capture.
12:31
Last year, the world's biggest carbon capture plant, Climeworks, went online in Iceland with much fanfare.
12:40
They announced that they could take 4,000 tons of CO2 out of the atmosphere every year.
12:40
If you do the math, that's just three seconds worth of humanity's emissions in one year from one plant.
12:40
You would need 10 million such plants at huge expense to actually deal with all of humanity's emissions.
12:40
To me, it's not realistic at all to think that we're going to reverse this.
12:40
We need to stop it.
12:40
One of the big takeaways here is that when we stop burning fossil fuels, the damage will stop.
12:40
At 1113 asks, "When will climate change stop?!"
13:15
Great question, and it has a very easy answer: when we end the fossil fuel industry and the animal agriculture industries.
13:22
At Kristen Smithson asks, "Whoa, chemically, how does methane react in our atmosphere and how does it affect our climate?"
13:28
That's a great question.
13:28
So methane is the second biggest cause of global heating in terms of the different molecules in our atmosphere after CO2.
13:36
It's an interesting molecule, one carbon with four hydrogens.
13:38
Once this goes into the atmosphere, it's an extremely powerful greenhouse gas, around 50 times more powerful than CO2, but it only lasts roughly 10 years, where CO2 stays in the atmosphere for hundreds or thousands of years.
13:51
Two main ways excess methane is getting into our atmosphere: number one, from drilling and mining of fossil fuels, so when you're getting this stuff out of the ground, you get some of this stuff escaping and leaking into the atmosphere as well.
14:03
And second, from various forms of agriculture and food waste decomposition.
14:08
At Jazzy Jazz Hill asks, "Why can't Cali be normal for a moment? What's up with this heat? (upside down smiley face)"
14:13
We have not reached a new normal.
14:15
We are on an escalator towards hotter and hotter temperatures, worse and worse heat waves.
14:22
But then you have this extreme drought, which is at least partially caused by climate change, and that's causing, you know, water shortages, massive wildfires, so the trees don't have enough water to drink and so they die and then forests burn very easily.
14:34
So when you have multiple impacts in one place, it just feels, it could feel like Armageddon, and that's exactly what we're seeing in California and frankly, all over the entire planet.
14:44
On average, this is the hottest summer you've ever experienced.
14:49
It's also the coolest summer for the rest of your life.
14:51
So those are all the questions for today.
14:52
Great questions.
14:54
Thanks for your interest in our planet.
14:56
It's the only one we got and I think it's pretty important to save it.
14:57
This is a climate emergency and this was Earth Support.