In order to avoid severe climate change, it is necessary to stabilize global greenhouse gas concentrations at about today's level. Significant emission reduction would require the countries that are primarily responsible to implement emissions- reducing measures immediately. The sooner a policy of climate protection is implemented, the less climate change damage humankind will face in future decades. The impacts of climate change are highly uncertain. However, the recent UN climate report confirms that more severe extreme climate impacts will cause economic damage. Future climate policy needs ideally to be global and long term.