Transcription
Okay, so for today's video, we are gonna discuss the greenhouse effect and climate change. So let's go ahead and get started.
Well, so let's begin with what is the greenhouse effect. First of all, the greenhouse effect is incredibly vital to the existence of life on Earth.
Okay, so what is a greenhouse? You know, a greenhouse is a glass building used to trap heat to grow plants in cooler areas. In the picture here, we have a greenhouse. It's trapping heat to keep the plants that are inside nice and warm. You know, pretend you're gonna go see a movie on a weekend. You drive in, you park, you get out, you go enjoy the show. You come back two hours later. You know, it's really hot inside your car because the windows have absorbed heat. For this reason, you would never, I hope, leave your dog locked in a car with the windows rolled up. That could very much be a fatal error.
So let's now talk about the greenhouse effect. You know, is there a glass building that surrounds planet Earth? Of course not. But Earth has an atmosphere that surrounds it that acts like a greenhouse. So the gases in Earth's atmosphere trap heat to warm the Earth. Gases, greenhouse gases such as carbon dioxide. Greenhouse gases such as water vapor. And greenhouse gases such as methane. They trap heat. In my animation, light from the Sun will reflect off the surface of the Earth. As that happens, these greenhouse gases will absorb heat near the surface of the Earth to warm the planet. Keeps Earth nice and comfortably warm.
You know, the greenhouse effect reminds me of Goldilocks and the three bears. You know, one of the porridges that she ate from was too cold. You know, there's a planet in our solar system that's too cold for life as we know it because it doesn't have a greenhouse effect. Mars. Mars has a very thin atmosphere. Very little heat is trapped, and for the most part, it's a frozen planet. It doesn't really have a greenhouse effect.
Well, this porridge is too hot. There's a planet in our solar system that is too hot for life as we know it because it has an extreme runaway greenhouse effect. I'm referring to planet Venus. Venus has a very thick carbon dioxide atmosphere. A lot of heat is trapped near the surface of Venus. And even though Mercury is closer to the Sun, Venus is still the hottest planet in the solar system because of its extreme greenhouse effect.
And then, if we finish off our Goldilocks analogy, this porridge is just right. There's a planet in the solar system that's just right for life. And of course, I'm referring to Earth. Earth has a life-giving atmosphere that traps just enough heat.
So what's the problem? Why are we having this discussion? Well, the problem is that the greenhouse effect, the natural greenhouse effect, is out of balance. And that's what this video is going to discuss.
So what do I mean by the greenhouse effect is out of balance? Well, what I mean is the Earth is getting warmer. You've probably heard of climate change or you've probably heard of global warming. And so, really, it's out of balance because of human actions. You know, the burning of fossil fuels such as coal, oil, natural gas. These rule, this releases a lot of carbon dioxide into the atmosphere. Carbon dioxide is a greenhouse gas. You know, the burning of fossil fuels is what provides energy for automobiles to to be driven. Burning of fossil fuels provides energy for industry to to conduct their business. Burning of fossil fuels powers homes to produce electricity.
You know, agriculture has played a role in the greenhouse effect being out of balance. For instance, the overuse of fertilizers on farms releases a lot of nitrogen oxides into the atmosphere. Nitrogen oxides are a greenhouse gas. The overproduction of farm animals has released a lot of methane into the atmosphere. Again, methane is a greenhouse gas.
The deforestation of forests around the world is contributing to the Earth getting warmer. Whether it's through clear-cutting, whether it's through slash-and-burn techniques. Deforestation removes photosynthetic plants that would normally absorb carbon dioxide and remove carbon dioxide from the atmosphere. Remind viewers, remember that carbon dioxide is one of the the reactants of photosynthesis. Plants will absorb and remove carbon dioxide from the environment in order to do photosynthesis.
And let's not forget the effects of water pollution in creating an out-of-balance greenhouse effect. You know, water pollution might runoff from farms into rivers, lakes, streams, and eventually oceans. You know, water pollution might runoff from storm drains and sewage. Water pollution, you know, from oil spills perhaps. And what we're seeing is a pollution, a polluted, a polluted, what, what we're seeing are polluted waterways. And as a result, we're seeing the slow death of photosynthetic algae. Just like plants, photosynthetic algae perform photosynthesis. So they too remove carbon dioxide from the atmosphere.
So if we come back to this animation before, here's again our natural greenhouse effect, a warm planet Earth. But really, since the Industrial Revolution, we've been releasing a lot more of these greenhouse gases into the atmosphere from the burning of fossil fuels, from the overuse of fertilizers, from the overproduction of farm animals. And as a result, we have a really a thicker atmosphere that is trapping even more heat near the planet's surface. And so this is the, this is the out-of-control, this is the man-made greenhouse, this is climate change.
Here, so what are some consequences of a warming planet? Well, some of the obvious ones, you know, the melting of glaciers and polar ice caps. You know, here's a picture of of the northern polar area. And in 1984, the picture on the left, 1984, versus the picture on the right of 2012. You can see a dramatic reduction in the northern polar ice cap. Well, all that water goes into the ocean when it melts, thus rising sea levels. You know, here's a picture of Venice, Italy. And if, if you've ever read or seen documentaries about some of the difficulties that coastal cities are having as a result of rising sea levels, now Venice, Italy is a great example of a city that's having some incredibly challenging problems now as a result of rising sea levels.
You know, another consequence of a warming planet are more severe weather storms. And this is simply because a warmer planet increases the rate of water evaporation. And eventually, water will evaporate at a faster pace. And then eventually, what goes up must come down. Well, that might be good for some areas that are receiving more rainfall than normal. But other areas are receiving less rainfall because the water is evaporating from certain areas at a faster pace. And the water evaporates and then blows away through the wind. And and other areas may receive more rainfall. But other areas are more prone to drought. And one of the side effects of drought would be a reduction of crop production. Simply put, if you're trying to grow crops in an area that may be in a drought, that's gonna reduce the crop yield. And I think California is first-hand witness to, to the one, to this particular consequence.
Yet another consequence of a warming planet is the spread of disease. You know, for example, here's the the mosquito that causes malaria and its larvae here, the mosquito larva. Well, I'm bringing up this example because this particular mosquito lives typically lives in a warmer climate area. And if the, in general, if the Earth's climate is becoming warmer, you would expect this mosquito to spread outward and kind of take advantage of new habitats and therefore spread malaria to areas of the world that aren't used to seeing it.
The final consequence I want to mention is one called coral bleaching. You know, here's a picture of a fairly healthy coral reef here, you know, very colorful, lots of aquatic fish. But here is an example of coral that's been bleached. Well, with just a few degrees increase of water temperature, it causes the algae that live inside of corals to die. And therefore, the corals then die. And once the corals die, then the habitat starts, the ecosystem, excuse me, starts to fall apart and break down. So we're seeing reefs, for instance, coral reefs begin to die around the world just because of a few degree warmer difference in ocean temperatures.
So what is some of the science and the data behind climate change and global warming? You know, since the Industrial Revolution, the rate of carbon dioxide in the atmosphere has greatly increased. This graph shows it nicely. Far right is kind of current day. And if you notice, in the middle of the graph, it says for 650,000 years, atmospheric carbon dioxide has never been above this line at 300 parts per million until now. So you see current day, we are way high on the carbon dioxide parts per million that have, that are accumulating in Earth's atmosphere, thus greatly contributing to climate change.
You know, this graph right here really shows nicely the correlation between carbon dioxide in the atmosphere and Earth's temperature. The blue line represents atmospheric carbon dioxide. The red line represents global average temperature. And you can see that as the blue line increases over the years, as the carbon dioxide increases over the years, so does the red line, so is the temperature. Now, one year the temperature might go up a little, the next year might drop a little, the next might go up, the next year might go down. But the general pattern is as the blue line increases, so it is the red line. This shows a correlation between carbon dioxide and temperature.
You know, various organizations have created computer models. And each one, each model kind of suggests the same thing: the continual warming of the Earth. Now, one model might might suggest the Earth will warm two degrees over the next, you know, 100, 200, 300 years. Another model may say the Earth is gonna warm three degrees. And others will say four degrees. But the general pattern is that the, of the models is that they all indicate and hint toward a continual warming of the Earth unless some very drastic actions are taken.
So what do I mean by take action? Well, this is one of the situations that is gonna require global cooperation. You know, for instance, just recently in 2015, the Paris Agreement is an agreement between nations of the world to pledge to reduce their greenhouse gas emissions. Well, while this sounds wonderful, the nations really only did make a pledge to reduce their greenhouse gas emissions. There's nothing legally binding. There's no legal consequences if a nation does not meet its pledge. But again, it's a step towards the right direction.
You know, around our home, we could look to reduce our use of fossil fuels. For instance, certain vehicles have better fuel efficiency than others. And while a hybrid or an electric vehicle doesn't completely solve the problem, it again will help to lessen the effect. You know, carpooling. If we're gonna drive to work or to school, if we can team up with one to three other individuals, that way you can, you know, reduce the amount of cars that are on the road. Biking, walking distances not only saves fossil fuels, but also it's wonderful exercise. Adjusting our heater in the winter, adjusting our air conditioner in the summertime. You know, during the summertime, having the air conditioner a few degrees higher than normal will save a lot of electricity. Exploring alternative energies. You know, certain cities or states or even federal, federal government might give tax incentives if you look into solar power at your home. And let's not forget planting a tree. The act of reforestation. Trees again remove carbon dioxide from the atmosphere. So the planting of more will help to remove more carbon dioxide from the atmosphere. And the promotion of organic farming. Organic farming does not use any fertilizers. And we mentioned fertilizers contain nitrogen oxides, which is one of the greenhouse gases responsible for climate change.
So there you have it. Go ahead and pause this video if you want to work on this quiz. And if you're in my class, feel free to write your answers on a separate sheet of paper and I'd be happy to check your answers either before school or after school. Thank you.