A Greenhouse is an ENCLOSURE for growing plants year-round, ISOLATED from current weather conditions. The Greenhouse contains Earthly atmospheric gases, and some absorb thermal energy via solar infrared. Nicknamed as 'Greenhouse Gas' and listed here in order of thermal significance:
Water Vapor Carbon Dioxide
CH4 Methane: Irrelevant Greenhouse Gas Details from non-political, pre~2010 informational sources. After ~2015 informational sources began political competition.
A bit of Greenhouse history:
The Greenhouse was in use 400+ years ago (17th century) and was heated by a wood-burning oven, even though Sunlight was as plentiful then as now.
Today a Greenhouse is warmed with (Propane) gas burner, or with electric heat.
Most Important for Earth's Heat: ...Water vapor is the 'working medium' of the atmospheric thermodynamic engine which transforms heat energy from Sun irradiation into mechanical energy in the form of winds...
The largest greenhouse gas by volume
(water vapor) is now overlooked by most people and many dictionaries.
Water vapor is the most abundant greenhouse gas in the atmosphere. [EPA]
Only 3 IR rays affect CO2(2.7, 4.3 & 15uM) Any of 35 IR rays affect water vapor
IR = InfraRed electromagnetic radiation,
wavelengths in micrometers (uM)
Earth's atmosphere is its superhighway to move water around the globe.
Is this now a game?
This has become a CO2 blame game. Man helped plants grow year-round, more hours per day than by the Sun. Man adds CO2 into that Greenhouse for plants to breathe healthier, NOT for heat.
Carbon Dioxide is a Carbon compound.
The pure element Carbon is found as graphite, and with millions of years of millions of tons of pressure, can become a diamond.
Carbon compounds are chemical substances with Carbon atoms bonded to any other element. There are more Carbon compounds on Earth than any other element except Hydrogen.
There are many sources of Carbon Dioxide. Nature includes decomposition, ocean release, our own respiration + animal respiration around the world.
Source examples may include cement production, and activity such as making beer & wine.
Man made the methods to burn several natural fossil fuels like coal, oil and natural gas.
Burning can produce CO2 as an exhaust gas, a gas which CANNOT produce heat.
Next 2 links are helpful for 8th grade science class.