Without the greenhouse effect, earth would be
a. too cold to support our current ecosystem
b. too warm to support our current ecosystem
c. too wet to support our current ecosystem
d. barren of all life

a. too cold to support our current ecosystem

Greenhouse effects help keep the earth warm.The earth has a natural greenhouse effect. It has been there since the beginning and has sustained life ever since.Naturally occurring greenhouse gases such as carbon dioxide and methane allow solar radiation to reach the earth's surface, while trapping radiation from the earth on its way back out to space.The trapped energy warms the earth's surface , making it about 35 degrees Celsius warmer than if we didn't have the greenhouse  gases in the atmosphere. There would be no life on earth without the warmth provided by this natural greenhouse effect.

If a particular resource is not useful or needed then the price would be considerably low. once that resource is needed the price or value will raise depending on how useful or needed it is especially if the resource is low in quantity, the consumers would pay whatever they have to, to get that material.