FEMA is clearly useless against such things as hurricanes and floods, because it moves far too slowly. Here is a list of emergencies that happen slowly enough for FEMA to handle.

A new ice age that would cover northern North America with a vast ice cap
Time frame: 10 thousand years

The melting of the existing ice caps and consequent flooding of coastal areas
Time frame: 25 thousand years

The breakup of North America along the Mississippi Valley
Time frame: 10 million years

The burnout of the Sun
Time frame: 5 billion years

Just put FEMA on these now, and FEMA will handle them on a timely basis.