Step 1: Understanding the Concept.
A carbon credit is a permit that lets its holder emit one tonne of carbon dioxide (or an equivalent greenhouse gas). Credits were formalised as a market mechanism under the Kyoto Protocol.
Step 2: Check option A.
The carbon credit trading system was indeed created alongside the Kyoto Protocol, so A is a true statement.
Step 3: Check option B.
Countries or groups that cut emissions below their allotted quota earn spare credits, which is a true statement.
Step 4: Check option C.
The whole point of the scheme is to cut carbon dioxide emissions globally, so C is true.
Step 5: Check option D.
Carbon credits are not priced by the United Nations Environment Programme. They are bought and sold on carbon exchanges (like any commodity), so their price is set by market demand and supply, not fixed by a UN body. This statement is false.
Step 6: Final Answer.
Option D is the incorrect statement.