The IPCC working group did not mean to provide a risk assessment of future climate change impacts and so it did not. (e360.yale.edu)
There are a number of areas where improved scientific information or understanding would enhance the capacity to estimate future climate change impacts. (nca2014.globalchange.gov)
Gaps in our understanding of climate response in the tropics and polar regions limit our ability to predict future climate change impacts in all areas. (giss.nasa.gov)