The carbon dioxide, greenhouse gases and other gases (nitrous
oxide and perfluorocarbons etc.) emitted through industrial scale
production, the energy sector, the burning of fossil fuel and other
activities are contributing in global warming and have negative
effects on the life itself on Earth. Public awareness on climate
change has considerably increased throughout the past couple of
decades, and in parallel the demand to change our way of living and
maintain a sustainable existence in harmony to nature. So,
countries and international organizations are seeking
implementations on a world-wide scale to fulfil this goal.
When countries or corporations (emitters) produce carbon dioxide
and other greenhouse gases, they do not pay for the full cost
implications. They pay direct costs, such as fuel and maybe other
costs, but there are other costs that are not necessarily in the
price of the good or service these emitters provide. These are
called external costs or
