Strange emission goals for G8 countries

From the BBC:

The G8 leaders are set this week to deliver their strongest statement so far on global warming.

They are likely to agree that the world ought to cut greenhouse gas emissions by 50% by 2050 - with rich nations reducing them by 80%.

The group will probably also say that any human-induced temperature rise should be held to 2C - a level considered to be a danger threshold . . . . .