Greenhouse Effect and Global Warming — Environmental Science — LetsTute

[00:00:00] Speaker 1: Global Warming and Greenhouse Effect Earth, the third planet from the sun. The only planet having a vast diversity of life forms. While other planets of our solar system are either scorching hot or bitterly cold, Earth has a relatively stable temperature. What is that which is making Earth different? What exactly is making Earth such a favourable place to live on? It is the Earth's atmosphere, which is a thin blanket of air surrounding the Earth from all sides. This air is a mixture of many different gases. Just like an umbrella which protects us from sun and rain, this thin layer of air protects Earth from the harmful radiations from the sun. But this stable temperature is rising every passing year. Oceans are getting warmer. Significant shift in the climate is seen. Glaciers are melting. Why is all this happening? What should be done to stop all this? We will find the answer to all these questions through this session. Earth is constantly bombarded with enormous amount of radiations from the sun, which we receive in the form of light and heat energy. These radiations in the form of visible, ultraviolet and infrared have to first pass the Earth's atmosphere before reaching the surface. The ozone layer which is present in the Earth's atmosphere blocks some amount of harmful ultraviolet rays from reaching the surface. Of the remaining rays reaching the surface, part of it is absorbed by the Earth. And some, especially the infrared waves, are reflected back into the space. But some gases in the atmosphere traps this heat radiation and re-emits it to the surface, which leads to heating up of the environment. This exchange of incoming and outgoing radiation that warms the Earth is referred as the greenhouse effect. And the gases involved in this are called greenhouse gases, which mainly includes carbon dioxide, methane, water vapour, chlorofluorocarbons, etc. Friends, but are you not wondering why it is called greenhouse effect? Is it something to do with the greenhouse? If you said yes, you are thinking in the right way. A greenhouse is a glass building in which plants that require protection from cold weather are kept. The glass cover helps to trap all the heat energy and keeps the inside environment warm. Now consider our planet Earth. The atmosphere acts as the glass and traps the heat. The greenhouse effect is essential in order to keep our planet warm. In the absence of this effect, the temperature of the Earth's surface would have been minus 20 to minus 40 degree Celsius. But too much of something is bad, right? If the plants in the greenhouse receives excess heat, it would burn. If we consider planet Earth, over the last two centuries, human activities have changed the Earth's atmosphere in a dramatic way. The amount of greenhouse gases have increased and are still increasing. They trap too much heat. And this excess of greenhouse effect results in global warming, which is an increase in the Earth's average temperature. Consequences of global warming are enormous. Its effects are not limited to one country, but it would affect the entire planet. Knowing the fact that global warming exists and human-made carbon dioxide emissions have caused it. Many nations of the world have come together to sign an international treaty, the Kyoto Protocol. The major objective of this protocol is our commitment to reduce greenhouse gases by about 5% below their 1990 levels. But what can be done by us? How can we contribute in reducing global warming and also its consequences? Well, planting more number of trees, reducing waste generation, reducing the use of products which generate greenhouse gases, using energy-efficient appliances, increasing the fuel efficiency of vehicles, using more renewable energy, or say, switch into greener ways, which causes less harm to our environment? That's all for today. I hope you found this session very informative and you got a thorough knowledge of what global warming is. [00:06:04] Speaker 2: I hope you like our video. You can also buy our courses in the form of DVDs, pen drives and online courses, which are available on different platforms. All links are given in the description box below. Press that bell icon and turn your notifications on. And also, please do not forget to like, comment, share and subscribe.