A faulty decision, dislike of presidential policies, or dislike of the President himself are not grounds for impeachment. Otherwise, none of our 44 White House occupants would have completed their terms.
Except in the most flagrant of cases (e.g. Watergate), it is extraordinarily difficult to justify impeachment of a president for exceeding the authority granted by the Constitution and federal statutes. Whether the president has transgressed is usually in the eyes of the beholder, and in extreme instances, in the interpretive hands of the courts. Invariably the White House has prevailed. That is why the idea in some ideologically fractious Republican circles to unseat President Obama through impeachment (i.e. treason, bribery, or high crimes and misdemeanors) is delusional wishful thinking.
On the other hand, some of the very Republican lawmakers spoiling for Obama's ouster could themselves be subject to future impeachment on a retroactive basis if such proceedings were ever allowed to take place.
It is future generations who will bear the brunt of any environmental inaction, and improbable as the scenario might seem, they should have the opportunity to convict the obstructionist lawmakers in absentia.
Let us be clear. We are not talking about members of Congress who somehow have genuinely convinced themselves that global warming is a hoax. We are talking about Republican lawmakers, who because of the preponderance of incriminating evidence, admit privately that they and the majority of their colleagues consider global warming to be real, if not human generated. It's just that they all fear political ostracism and primary challenges if they dare publicly stray from the strict party line of denial.
These lawmakers may not think global warming is as dire a threat as many scientists do, but there is enough available evidence not to take the risk in good conscience. That is especially true if the counter measures (such as greater energy efficiency and climate research programs) have societal benefits regardless of global warming's ultimate impact.
It is hard to argue against blaming these legislators if their reprehensible stonewalling out of anti-Obama sentiment or for short term partisan gain leads to realization of the worst global warming projections.
That said, the nation cannot afford to wait for ex post facto justice in the form of future impeachment for crimes against humanity, even if such a procedure were feasible. The good news is that the public can exercise its own form of impeachment by voting the obstructionists out of office before it is too late.