There is also uncertainty about determining the outcome of the trend of global mean temperature after 20 years. (julesandjames.blogspot.ru)
Recent studies estimate that even for conservative global mean temperature increases, between 11 % and 34 % of species alive today could be threatened with extinction. (heritagewindenergy.com)
This fact proved sufficient to obtain useful estimates for global mean temperature changes. (data.giss.nasa.gov)