As someone working in this field, I would just like to make some clarifications. The term 'Climate Change' is better viewed as two separate questions: is climate change occurring, and if so, is it due to human influence? The first question is effectively settled; temperatures are increasing and extreme weather events are occurring more frequently. The second question is more complex, although the vast scientific consensus is that it is indeed due to human influence. In particular, the greenhouse effect has been conclusively proven. The slightly-informed seem to misinterpret scientific uncertainty (a very specific term referring to statistical probabilities) with a much more general 'scientists aren't sure if this is true or not'.
It is true that there is a long way to go in climate science. However, this is no reason not to teach it in schools. There are many unknowns in the science (as with any field of science); these should not be understated, but neither should they be overstated - it would not be helpful for teachers to spread yet more excessive doubt. Finally, it is of particular importance that climate science is taught in school - the consequences of climate change are likely to be extremely grave for mankind and will impact the next generation much more than this one.
"Though a program be but three lines long, someday it will have to be maintained." -- The Tao of Programming