There are so many influences and feedbacks on climate, many which we dont yet fully understand, and maybe even some we dont know about, to say there is a direct relationship between GHG concentrations and warming, but there is definatly a relationship between GHG and climate.
e.g
As the snow melts, this lowers the amount of radiation the snowcover reflects, which causes more localised warming as the permafrost and snow cover melts. (sea and vegetation absorb more radiation than snow cover)
The ocean acts as a buffer, absorbing GHG but if it warms enough there is a possibility deep ocean stores of GHG may be realised, with the potential for warming.
these are two examples of many feedbacks in the climate system that climatolgists are trying to understand and incorporate into climate models.