Causes of Global Warming – the Human impact:
Greenhouse gases have risen sharply since 1958, primarily due to the Industrial Revolution. Since then, humans have increasingly been contributing unnatural sources of greenhouse gases into the system, causing the system to become unbalanced.
The Greenhouse Effect
The Earth maintains a habitable temperature due to the Greenhouse Effect, which allows heat from the sun to penetrate our atmosphere, where it is absorbed by the Earth’s surface or radiated out and reflected back to Earth by greenhouse gases in the atmosphere. Without it, the Earth would be a cold and hostile planet, and would most likely be uninhabitable.
However, maintaining the natural balance necessary to keep the Earth’s temperature within a range that is viable for life as we know it is a very fine line that can easily be crossed.
Greenhouse gases are naturally occurring gases that pose no harm when they are in balance. However, when they are present in excess, the system becomes unbalanced and things start to go awry.
“When we burn organic (i.e. carbon-containing) fuels, or when organic matter decomposes, carbon dioxide is released into the air. It is transparent to incoming solar radiation, but opaque to some wavelengths of heat radiated from the warmed surface of the Earth, and so traps heat, leading eventually to a warming of the lower atmosphere”.