One of my friends asked me this riddle, “There is a red house made of bricks, a blue house made of bricks, an orange house made of bricks. What color bricks is a greenhouse made of? “. And then I answered him quickly that it’s green. But I was wrong. I can’t figure it out why, until he said that, “A greenhouse is made of glass or plastic, not bricks”
This is actually a scientific fact. A greenhouse is a simple structure that is really bounded by translucent materials such as glass, fiberglass and plastic. The close environment is used for cultivation because of its ability to trap the thermal energy or heat that is necessary for growing of plants.
The concept of a greenhouse is very easy to understand. We know that plants need water (H20), carbon dioxide (CO2) and nutrients from the soil for them to be able to produce sugar or carbohydrates by means of photosynthesis where the heat of the sunlight is used. Now, when the sunrays reach the glass roofs and walls, they will pass through because of transparency, making the soil and air to emit infrared heat. The role of carbon dioxide is to absorb the infrared heat, preventing it to escape from the greenhouse.
Thus, heat energy is conserved and being maximized by plants and their process of making food.
But, what is the contribution of greenhouse effect to the problem of global warming?
It is actually like this. Imagine that the earth is a big greenhouse and our atmosphere is the glass roofs and walls. The sunbeam towards the earth is being screened by our atmosphere, some radiations are being scattered back to the space and some will reach the lithosphere or land surface. Then, infrared radiation is produced because the soil and air is being heated up by the UV rays from the sun. The tendency of infrared rays is to go upward and directed back to the atmosphere. However, here come the greenhouse gases like CO2, water vapor, ozone and methane that disallow their escape from the earth causing thermal energy to stay in the surface. Due to this, the overall temperature of the world is increase continuously and unusual climate change is observed dramatically.