According to Thomas, the legislative information service of the Library of Congress, the mission of the United States Emergency Management Authority (USEMA) will be:

    (1) lead the Nation's efforts to prepare for, respond to, recover from, and mitigate the risks of natural and man-made disasters, including catastrophic incidents;

    (2) partner with State and local governments and emergency response providers, with other Federal agencies, with the private sector, and with nongovernmental organizations to build a national system of emergency management that can effectively and efficiently utilize the full measure of the Nation's resources to respond to a catastrophic incident or other natural or man-made disaster;

    (3) develop a Federal response capability that, when necessary and appropriate, can act effectively, rapidly, and proactively to deliver assistance essential to saving lives or protecting or preserving property or public health and safety in a natural or man-made disaster;

    (4) fuse the Department's emergency response, preparedness, recovery, mitigation, and critical infrastructure assets into a new, integrated organization that can effectively confront the challenges of a natural or man-made disaster;

    (5) develop and maintain robust Regional Offices that will work with State and local governments and emergency response providers to identify and address regional priorities;

    (6) under the leadership of the Secretary, coordinate with the Commandant of the Coast Guard, the Director of Customs and Border Protection, the Director of Immigration and Customs Enforcement, the National Operations Center, and other agencies and offices in the Department to take full advantage of the substantial range of resources in the Department that can be brought to bear in preparing for and responding to a natural or man-made disaster;

    (7) carry out the provisions of the Robert T. Stafford Disaster Relief and Emergency Assistance Act (42 U.S.C. 5121 et seq.);

    (8) provide funding, training, exercises, technical assistance, planning, and other assistance, to build local, State, regional, and national capabilities, including communications capabilities, necessary to respond to a potential natural or man-made disaster;

    (9) implement an all-hazards-plus strategy for preparedness that places priority on building those common capabilities necessary to respond to both terrorist attacks and natural disasters while also building the unique capabilities necessary to respond to specific types of incidents that pose the greatest risk to our Nation; and

    (10) promote, plan for, and facilitate the security and resiliency of critical infrastructure and key resources, including cyber infrastructure, against a natural or man-made disaster, and the post-disaster restoration of such critical infrastructure and key resources.

So now I have dig up an official description of FEMA's mission and compare the two.