Humans are not well equipped by evolution to mitigate any problem that has a time frame longer than the typical duration of fertility (maybe 30 years). There is no evolutionary selection pressure for such a trait to be incorporated into our psychology (the trait confers no reproductive advantage since such advantage would occur after reproduction has occurred). So, although we realize pretty quickly that an impending midair collision is best avoided with quick evasive maneuvering we deny and fail to act on threats that are decades in the making (or the fixing).
Like Paul B, I find it hard to have much optimism about the human response to anthropogenic climate change (global warming). Many of the comments here reinforce my pessimism about the future.