O que é o Aquecimento Global? | WebSérie Mudanças Climáticas | Ep. 1

Hey guys, it's nice to have you here for the first episode from our webseries about climate change. when someone talks about “Siberia” probably what comes to your mind it's a completely frozen place. And you're not wrong because in this region it is usually very cold very very cold!

But in 2020 it had a heat wave so hot there that the small siberian town Vercoyansk recorded the incredible temperature of 38 degrees Celsius! Try to imagine a place that has polar cold with the summer heat from Copacabana! And it's not just the heat causing problems over there the fire has also showed its power.

Between 2019 and 2021 Siberia suffered voracious fires that destroyed millions of hectares of forests including forests that rarely burned. The fire was so intense that the smoke could be seen from space. In recent years, extreme events like this are getting each increasingly intense and more frequent.

This has everything to do with the global warming a phenomenon that is making the Earth's average temperature rise and causing a worldwide climate crisis. Although it seems that the “Global Warming” topic suddenly appeared actually it is already talked about from a long time. 120 years ago researchers like Jean Furrier John Tyndal and even Ahrrenius himself they already knew that the change in concentration of gases in the atmosphere caused changes in the weather.

Even in 1986 the chemist Ahrrenius demonstrated with calculations that earth's temperature would rise if the levels of the greenhouse gases increased exactly what's happening today! So it's nothing new that weather and climate can change with our influence. By the way, you know the difference between weather and climate?

Despite often people use them as synonyms these terms have different meanings. weather is an event or a specific condition that occurs during a short period of hours or days. For example, a storm, a dry day today's temperature this is all weather.

The climate is something wider it is the average weather conditions in a place along many, many years usually at least 30 years. For example, the weather in Brazil is hot and humid. this is the result of an average that was withdrawn from results of several years even because we have warmer years and colder years but the average, if you get all results and take an average the result will always give that the climate of Brazil it's hot and humid.

We are already trying to predict the climate for hundreds of years. In the past in the first civilizations known to man people already produced calendars according to the seasons of the year and specific weather events such as long rainy periods or drought. And so they could predict which would be the best time of year to plant to harvest, all planned in advance based on weather forecasts.

A problem obviously it was the imprecision because they relied a lot in observations of weather events such as rain, drought, wind, but they had no tools which gave more accurate measurements These predictions only started to improve when we created tools such as barometers thermometers, anemometers to measure pressure, to measure temperature and to measure the wind speed. Then we could get more data not only relying on see the shape of the clouds or to feel the skin temperature and wind. We started to have numbers!

And these technologies were evolving more and more and so today the weather forecast is MUCH better and the climate forecast, then wow, that one is super accurate. We even gave names for the seasons in some periods as is the case of spring, summer, autumn and winter because these moments, these seasons, they are predictable But if we consider the different ages of time on earth with intervals of thousands of years the climate varied a lot. And it keeps changing Today's climate, it's quite different from the Cretaceous climate, for example.

And for us to understand the reasons behind the climate changes we need to understand physics, chemistry and biology as well. We can divide the factors that influence the earth's climate in three processes. The first is how much the planet warms up considering the energy that comes from the sun the energy that gets trapped here and the energy that goes back to space.

The second factor that influences the climate is the way the atmosphere, the ocean and the ice sheets behave in front of Earth's natural warming. All the answers, they're intertwined and they can increase or decrease the changes of planet temperature. And the third factor that influences the climate is that each region has its specific conditions but these regions, they keep communicating and influencing the planet and also other regions that are nearby.

Got confused? I will give you an example: Antarctica, has it's climate with its own characteristics but it sends air masses to other locations influencing others regional systems. You must have heard it, right?

the air mass that came from Antarctica brought rain to Brazil, in other words region-specific conditions are influencing the climate of another region the same thing goes to the Amazon that has its characteristics and own climate but send rain to other places influencing the climate, for example, of Southeast Brazil. So, despite the systems be regional they are always intertwined. The opposite also applies: the world climate, it will also influence the climate of the Amazon and the Antarctic climate.

Ok, so you got it that the world climate, it it's all connected. But it doesn't mean that the weather has to be similar across the planet. If in your city temperature is lower or greater than the planet average this is completely normal.

This happens because each system it's like a city they have their own features. the mix of all these factors defines the weather and a weather can be warm even if the exists few days in the year when it becomes cold. Remembering that a cold day is weather global warming is climate.

And it's the climate that we're talking about. So now I want to focus on just one of these factors that influence the climate we will understand the atmosphere and it's answers. Because Earth's Atmosphere is made up of different gases.

Nitrogen gas is the dominant but you can also find oxygen which is the one we breathe and you will find it in the atmosphere gases that absorb heat like carbon dioxide. This heat absorption causes a known effect as the Greenhouse Effect. When we think of greenhouse we remember those plant greenhouses those houses made plastic or glass where there are several plants.

the transparent wall let the light in and then it heats the air that's inside. At night, the warm air try to escape but the glass wall, makes it difficult for the air to leave what keeps the inside temperature of the greenhouse warm. The greenhouse effect, it works in a very similar way and keeps the planet warm.

The energy that comes from the sun arrives on earth in the form of waves. These waves can have different lengths and those who can pass through the atmosphere which is like the “glass” of our greenhouse are the shortest waves with the length close to visible light. Earth, for being WAY colder than the sun irradiates that energy back to space in the form of much larger waves than those that arrived from the sun these bigger waves we call it infrared waves.

But these waves they can't cross the atmosphere to go back to space and that's what warms our planet. The Greenhouse Effect is essential for the planet we know without it, the Earth would not be hot enough. But the big problem is this effect to be intensified.

And we are interfering In the atmosphere increasing the greenhouse effect and provoking what we call Global Warming. And one of the main responsible for this heating is the overproduction of carbon dioxide by human activity. And carbon dioxide is one of the gases of the atmosphere that absorbs heat and spreads back to the surface.

Absorption occurs because the infrared waves interact with molecules of carbon dioxide and make the shape of these molecules change what will leave the molecules unstable and make them spread that energy back to the surface to return to stability. So basically the gas carbon absorbs energy and then releases that energy so then it becomes stable again And now We already know about this role of carbon dioxide in the atmosphere for a long time. Back in the 19th century, during the industrial revolution the amount of carbon dioxide released started to increase while the population world was also growing.

And as I told you in the beginning of the video in the 19th century, important figures, such as Jean Furrier, John Tyndall already demonstrated that the planet would be colder if it didn't have an atmosphere and that the change in concentration of gases in the atmosphere could cause a climate change. And at the turn of the 19th century for the 20th century we had a super striking event. The researcher Arrhenius he published the first global warming calculation caused by emissions of carbon dioxide.

It's not recent, I told you. After hundreds of calculations he came to the conclusion that if the levels of carbon dioxide from the time being fell by half the average of Earth's temperature would fall 5 degrees and that if the levels doubled the average temperature would rise 5 degrees. Yes, almost 120 years ago we already had access to these numbers even if they were still preliminary and did not show reality accurately.

But we had a notion how the atmosphere was influenced by gases. Since then, knowledge about global warming started to get increasingly robust. Today we already have a consensus which is that the human activity, it is causing an increase in the amount of carbon dioxide on the atmosphere and that we are on the way to double the amount of carbon dioxide.

for us to accept the scientific consensus it is essential for us to change this reality that we are going through which is the case with extreme heat waves. Indeed, the scientific consensus it's very strong, knowledgeable evidence based. an individual alone he is not able to understand an entire study area but many people together specialists in different areas getting at the same conclusions show to us the power of one scientific consensus.

99. 9% of scientists agree that the global warming is being caused by human activities. It's a lot of competent people, in the whole world studying the topic and having the same conclusion.

And that 0. 01% that doesn't agree probably have some economic concern in it. Climate change that is real today it's ongoing, and getting worse.

We have the expectation, the climatologists that with the next El Niño event and if it's not this year, it will hapen in two years That is, until 2025 we are going to hit 1. 5ºC And then we'll see severe events like these viewed in 2019, 2020, 2021 to drop behind. We already know, for example, that in recent years we had temperatures higher global averages than 75% of observed temperatures of the last 11,300 years.

And the recent increase of the temperature it is so acute that stands out in any comparative chart it's a big jump that creates an almost vertical elevation. “But Jubilut, but aren't these Earth's natural cycles? I understand why you think so.

Looking at the planet history indeed, this planet was much warmer than it is today. The surface temperatures they exceeded 200 degrees Celsius 4 billion years ago. It got that hot for a good while on earth and then it got cold slowly.

for a few million years it also got very cold and then returned to present global warming in cycles that took millions of years to happen. we live at the moment on a planet a little colder than its historical average in a period called interglacial period. For us to go back to a time where the average global temperature were warmer than today we have to go back 130 thousand years in the past in the Eemian period that lasted about 15,000 years.

During this period, earth's temperature was quite stable and it was about 2 degrees higher than it is today. Several species from that time had very different distributions in a way that they stayed far away from hotter places. Just for you to have an idea the hippos of that period they could live in places with higher latitudes as is the case with British Isles!

so you could found at that time hippos in british isles So, over 115,000 years ago earth doesn't have temperatures so high as the ones that we have today. 115 thousand years! The heating process of the planet is happening very quickly without allowing the species time to adapt.

We have studied enough cooling and heating cycles to ensure that this fast pace it is not what is expected. the planet is warming up in hundreds of years what took thousands of years to warm up in the past times. When we say that the current climate change outlook is accelerated it is accelerated because it is not natural And then we'll combine logging emission of polluting gases of the most diverse.

The rise in temperature is an element that we measure and that it is easy for people to understand of the global climate change. Another element is that the oceans getting hotter because it absorbs energy. With Global Warming we reversed nature's logic of planet Earth.

the temperature is rising even with the altitude that's why the glaciers are melting and that's why it has biodiversity that you won't have anywhere higher to go. because it will arrive at top of the mountain and will disappear So now that we have all this information with us we have the necessary expertise to make excellent weather forecasts. predictions so good that we can use to prevent scenarios that will be very harmful for society like climate crisis scenarios.

If we solved today all environmental issues and we must resolve. Our way of relate to nature our consumption pattern what I'm saying: I consumed intelligently. I will not stop consuming what I have If I have a car, air conditioning, no!

I just have to use the proper equipment that has the best cost benefit, including my financial life that's what i'm saying. If I consider all this the climate change will catch the generation of my grandchildren No doubt. And I have a 8 years old son.

So I consider what I I'm leaving him as a environmental heritage. That's why so many times I've been using the ecocide expression and that the UN is now adopting as something to have a international and legal base to arrive at a certain nation, in a given region and say like this: look, you destroyed the forest depleted the water without forest and water, there is no life. You will suffer, right?

sanctions, penalties because what you're doing is against humanity against life, in a general sense. All our actions, all our future economic, financial and health is on that agenda. The IPCC report that is the Intergovernmental Panel on Climate Change showed that heating it is happening even faster than scientists thought.

The latest projections show that, in the best case scenario the temperature of planet will rise 1. 5 in the next two decades. And it's very important that we stay below this value 1 and a half degree because the consequences if we go through it they will be devastating.

And look what I'm going to tell you: And even if we reach that minimum value of rising temperature even so, we will have to deal with complicated consequences to manage as is the case with species extinction the rise in sea level human migrations the increased frequency of pandemics and many others terrible things. Yes, we are powerful enough to change an entire planet this is obvious. after hundreds of years of studies we understood that human activity it modifies the composition of the atmosphere and that the increase of the greenhouse effect it provokes the global warming.

And we also understood that fast heating causes a severe climate change which leads to a climate crisis which is what we are facing now. What we can do as a society is to lessen the drastic effects of a climate crisis since great deeds that we had as a society in the last 8 thousand years like agriculture settlements permanent in cities and even our population growth relied on the stable climate that we had. Meaning that: we don't know how to live on a different planet nor the other species that are here with us.

Living on this unstable Earth different than we are used to with regions showing different climates it will be such a big challenge but so big that the best we can do is to try to avoid problems at all costs. Everything we standardized regarding agriculture will potentially be lost and cities will have to deal with cold waves and extreme heat increasingly frequent. The saying that it's better safe than sorry never made so much sense.

If we don't slow down now our production of greenhouse gases we will be burying the future society in a lot of issues difficult to solve. In the next video in this series I will bring it to you details on the most critical gases for global warming where are they coming from and how they affect our atmosphere. Furthermore, needless to say it was a great pleasure be here with you a big hug bye!