Answer:
The is biased because the earlier there was no global warming causing due to carbon dioxide and methane gas.
They are important green house gases which helps in maintaining the optimum temperature on earth which supports life.
The green house effect has became a problem due to increase in the concentration of carbon dioxide and methane in the atmosphere.
The life forms on earth that can survive better in the warm condition are favored by high temperature.
Because of these reasons the conclusion is biased.