Global Warming
Global warming is a phenomenon where the earth’s average temperature rises due to increased amounts of greenhouse gases. Greenhouse gases such as carbon dioxide, methane and ozone trap the incoming radiation from the sun. This effect creates a natural “blanket” which prevents the heat from escaping back into the atmosphere. This effect is called a greenhouse effect.
Contrary to popular belief, greenhouse gases are not inherently bad. In fact, the greenhouse effect is quite important for life on earth. Without this effect, the sun’s radiation would be reflected back into the atmosphere, freezing the surface and making life impossible. However, when greenhouse gasses in excess amounts get trapped, serious consequences follow. The polar ice begins to melt, leading to the rise in sea levels. Moreover, the greenhouse effect is faster when polar ice caps and sea ice melts. This is due to the fact the ice reflects 50%-70% of the sun’s rays back into space; but without ice, the solar radiation gets absorbed. Seawater reflects only 6% of the sun’s radiation back into space. What’s more frightening is the fact that the poles contain large amounts of carbon dioxide trapped within the ice. If this ice melts, it will significantly contribute to global warming.
A related situation occurs when this phenomenon goes out of control is the runaway-greenhouse effect. This situation is essentially similar to a catastrophe, but it is all too real. Though this has never happened in the earth’s entire history, it is speculated to have occurred on Venus. Millions of years ago, Venus was thought to have an atmosphere similar to the Earth’s. But due to the runaway greenhouse effect, surface temperatures around the planet begin rising.
If this occurs on earth, the runaway greenhouse effect will lead to many unpleasant situations – temperatures will rise hot enough for oceans to evaporate. Once the oceans evaporate, the rocks will start to sublimate under the heat. To prevent such a situation, proper measures have to be taken to stop climate change.
A greenhouse is made of glass that can be used to grow plants. The sun’s radiations warm the plants and the air inside the greenhouse. The heat trapped inside can’t escape. It warms the greenhouse which is essential for the growth of the plants.
Same is the case in the earth’s atmosphere. During the day the sun heats up the earth’s atmosphere. At night, when the earth cools down the heat is radiated back into the atmosphere. During this process, the heat is absorbed by the greenhouse gases in the earth’s atmosphere. This is what makes the surface of the earth warmer, that makes the survival of living beings on earth possible.
However, due to the increased levels of greenhouse gases, the temperature of the earth has increased considerably. This has led to several drastic effects.
Greenhouse gases are the gases that absorb the ultraviolet radiations and create a greenhouse effect. For instance, carbon dioxide and chlorofluorocarbons (CFCs).
The major contributors to the greenhouse gases are factories, vehicles, deforestation among others. The increased number of factories and vehicles increase the amount of these gases in the atmosphere. The greenhouse gases never let the radiations to escape from the earth and increase the surface temperature of the earth. This then leads to global warming.
How can we stop global warming?
- Where possible, we can switch to renewable sources of energy (such as solar and wind energy) to power our homes and buildings, thus emitting far less heat-trapping gases into the atmosphere.
- Where feasible, we can drive electric vehicles instead of those that burn fossil fuels; or we can use mass transit instead of driving our own cars.
- Where affordable, we can conserve energy by better insulating our homes and buildings, and by replacing old, failing appliances with more energy-efficient models.
- Where practicable, we can counterbalance our annual carbon dioxide emissions by investing in commercial services that draw down an equal amount of carbon out of the atmosphere, such as through planting trees or carbon capture and storage
Stabilizing global temperature near its current level requires eliminating all emissions of heat-trapping gases or, equivalently, achieving a carbon-neutral society in which people remove as much carbon from the atmosphere as they emit. Achieving this goal will require substantial societal changes in energy technologies and infrastructure that go beyond the collective actions of individuals and households to reduce emissions.
By: Tanvi Gupta 7D
