Extending the protocol will be discussed, but if a compromise is not reached, there may not be another international environment-related pact until 2020.

Lemmings extinct because of Ice Age warmth

New research shows that rapid climate change led to the extinction of lemmings, small rodents that inhabited the Arctic during the last Ice Age.

Their presence came in waves during the Late Pleistocene, 11,700 to 126,000 years ago. Experts believe they died out and then reappeared on several occasions in the span of 114,300 years.

The findings go against some suspicions suggesting that humans play a key factor in global warming.