Why do only greenhouse gases harm the environment?

Gases that harm the environment are commonly called greenhouse gases and cause global warming. Carbon dioxide tops the list. Many other gases such as nitrous oxide or methane are also included. Nitrous oxide is also called laughing gas. Methane gas is an essential component of natural gas that we burn in stoves for cooking or in geysers for heating water. Although carbon dioxide is considered the worst because of its quantity, in fact if one looks at how harmful a gas molecule is, other gases in it are even more harmful than carbon dioxide.

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For example, a molecule of methane that reaches the atmosphere raises the temperature 120 times more than a molecule of carbon dioxide. But the good news is that methane molecules can't stay in the atmosphere as long as carbon dioxide molecules. To eliminate this distribution of gases, the remaining gases are usually added to the amount of carbon dioxide in such a way as to accurately measure the change in temperature. In fact, it is not the amount of greenhouse gases that matters, but how much the temperature changes. When all gases are expressed as carbon dioxide, that amount is equivalent to 51 billion tons per year. The amount of carbon dioxide alone is 37 billion tons while the amount of carbon is 10 billion tons.

How do greenhouse gases increase the earth's temperature? The short answer is that the molecules of these gases absorb heat and get trapped in the atmosphere. You see examples of this in cars every day. Suppose you leave your car in the sun in summer. After a while, when you get in your car, your car gets warmer than the atmosphere. This is because the windshield of the car allows heat to come in but prevents it from getting out. This keeps the car warmer than the environment.

This explanation may have raised more questions in your mind. How is it possible that the heat of the sun passes through the greenhouse gases and reaches the earth but then the same heat is trapped in the atmosphere on return? Does carbon dioxide act as a one-way glass? If carbon and methane absorb heat and cause a change in temperature, why not other gases like oxygen?

The answer to all these questions lies in some basic principles of physics and chemistry. We know from the basic principles of physics that all molecules vibrate, and the faster the vibration, the hotter it gets. We also know that if light of a certain wavelength hits a particular molecule, that molecule blocks the light of that wavelength and absorbs its energy or heat within it and thus further increases its vibration and inevitably the heating of this molecule also increases. Not every light has the wavelength that it absorbs, so the waves of light coming from the sun reach the earth without being absorbed into the greenhouse molecules and cause the earth's temperature to rise.

The earth cannot keep this temperature inside for long and inevitably emits. By the way, if the earth kept this temperature inside, it would not be able to survive anyway. Now when the earth emits this heat, some energy is emitted from the same wavelength which is most suitable for absorbing carbon dioxide or methane.

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Due to this, the heat is trapped in the atmosphere and its heat continues to reach the earth. By the way, a certain amount of these gases is necessary for life. If these gases did not exist, the Earth would send all its energy or heat into the atmosphere at night and its temperature would drop to such an extent that it would be impossible to stay on it.

Other molecules, such as oxygen and nitrogen, have the same type of atoms, so they allow heat to pass through instead of being absorbed. In contrast, gases such as methane or carbon dioxide whose molecules are made up of different atoms absorb heat.

Thank you for reading! Stay Safe!👋😌

References:

1- https://www.britannica.com/science/greenhouse-gas
2- https://www.livescience.com/37743-greenhouse-effect.html