It is true that at present, no artificial intelligence is capable of general reasoning. It is also true that at present, carbon dioxide levels are not high enough to trigger a runaway greenhouse effect. Just as we cannot conclude from current carbon dioxide levels that there is not risk of a runaway greenhouse effect in the future, we similarly cannot conclude from current AI capabilities that there will never be an AI that can reason generally. In fact, just as carbon dioxide levels are rising every year, the trend of current AI is toward more and more general reasoning abilities that are transferable from one task to another.*
*As it happens, there are reasons to believe that earth will not experience a runaway greenhouse effect as a result of anthropogenic climate change, but the current carbon dioxide level is not one of those reasons.
Extinction Risk from Artificial Intelligence 