why are greenhouse be more in use nowadays as they produce co2 and other harmful gases?
The green house does not produce green house gases, but it utilizes the already present green house gases to increase the temperature inside the structure called green house necessary for the growth of plants. Green house is a structure having transparent walls and roofs made up of glass which is used for cultivating and protecting the pants. The roofs and walls allows the sun rays to get inside the room but restrict its passage to go out of the room resulting in the increase of temperature inside the room. Thus, the plants can be cultivated inside a close glass room providing it with required heat, light and temperature.
The green house gases include methane, carbon dioxide, nitrous oxide etc. These gases are mostly produced burning of fossil fuels like coal, petrol etc.