Politicians and international organizations think we can stop climate change by eliminating 0.13% of the greenhouse gas in the atmosphere in spite of the fact that climate has been changing all by itself for four billions years. “…the most dangerous greenhouse-gas emissions come from the front ends of politicians, not the back ends of cows…” – Walter Russell Mead
The “greenhouse effect” is proposed as an atmospheric “blanket” that keeps Earth warm. However, the term “greenhouse effect” with respect to the atmosphere is an unfortunate analogy because it is misleading. The interior of a real greenhouse (or your automobile parked with windows closed and left in the sun) heats up because there is a physical barrier to convective heat loss. There is no such physical barrier in the atmosphere. The greenhouse hypothesis deals only with heat transfer by radiation and conduction, but completely ignores convective heat transfer. Convective heat transfer in the atmosphere shreds the alleged “blanket.”
In short, the “greenhouse effect” is this:
Solar radiation, mostly short-wave radiation, passes through the atmosphere and warms the surface. In turn, the heated surface re-radiates energy as long-wave infrared radiation back to the atmosphere and eventually, back to space.
Greenhouse gases in the atmosphere intercept specific wavelengths of the long-wave infrared radiation and transfer some of the energy to excite (warm) other molecules in the atmosphere, some of the radiation goes back to warm the surface, and some of the radiation is radiated into space. Once all or most of a specific long-wave infrared radiation wavelength is intercepted (become saturated), additional amounts of a greenhouse gas will have no effect. Carbon dioxide reaches saturation at about 280 parts per million (ppm). Currently carbon dioxide is at 413 ppm. (Source)
The major greenhouse gases, water vapor, carbon dioxide, and methane, represent about 2% of the atmosphere. Water vapor comprises 95% of total greenhouse gases in the atmosphere. Carbon dioxide comprises 4% of total greenhouse gas. Human carbon dioxide emissions represent just 3.4% of atmospheric carbon dioxide, or 0.13% of the total greenhouse gas. (Source)
Do you think that eliminating 0.13% of greenhouse gas can significantly effect global temperature? I think not.
This table from Geocraft shows more detail (and slightly different) data about greenhouse gases: