Download The Greenhouse Effect is caused by an atmosphere containing

The Greenhouse Effect is caused by an atmosphere containing gases that
absorb and emit infrared radiation. Greenhouse gases “trap” heat within
the surface-troposphere system, causing heating at the surface of the
planet. This mechanism is fundamentally different from that of an actual
greenhouse, which works primarily by isolating warm air inside the
structure so that heat is not lost by convection.
The Earth receives energy from the Sun mostly in the form of visible and
ultra violet light. About 50% of the sun's energy is absorbed at the
Earth's surface, the rest is reflected or absorbed by the atmosphere.
When the ground is heated, the surface emits energy back into space as
infrared (IR) radiation (long-wave). Much of this radiated energy does
not make it into space, but is absorbed by greenhouse gases in the
atmosphere. These gases subsequently re-radiate a spectrum of IR
radiation (“heat”) in all directions, including back to the Earth's surface.
Heat transfer is also possible by collision with other atmospheric
molecules (the net effect is to increase the kinetic energy of the other
molecules).
By their percentage contribution to the greenhouse effect the major
gases are:



water vapour, 36–70%
carbon dioxide, 9–26%
methane, 4–9%
In the absence of a “natural” greenhouse effect the planet's mean
temperature would be far lower - about -18 or -19 °C
Global warming: a recent warming of the Earth's surface and lower
atmosphere, is believed to be (but there remains debate) the result of an
"enhanced greenhouse effect" due to human-produced increases in
atmospheric greenhouse gases. This human induced part is referred to as
anthropogenic global warming - primarily as a result of increased
emissions of carbon dioxide and methane.
Climate Change: unchecked global warming could result in catastrophic
climate change (ice caps melting/sea-level rising). Given the enormous
complexity of the atmosphere/oceans it is very hard to predict or model
– contrary to some reports in the popular media.
Questions

How does the glass/plastic greenhouse in a garden work? Why does
the inside of a greenhouse warm up in the first place?

How is the “Greenhouse” effect on Earth different?

What are the mechanisms that prevent/limit IR radiation escaping
into space? (How does a Greenhouse Gas work!)

Given that there is significantly less methane in the atmosphere
than carbon dioxide what comment can you make about methane’s
percentage contribution to global warming.