Further action is required to address remaining gaps in information and understanding. Systematic observations and data reconstructions Modelling and process studies. Recent regional climate changes, particularly temperature increases, have already affected many physical and biological systems. There are preliminary indications that some human systems have been affected by recent increases in floods and droughts. Natural systems are vulnerable to climate change, and some will be irreversibly damaged.
Many human systems are sensitive to climate change, and some are vulnerable.
Projected changes in climate extremes could have major consequences. The potential for large-scale and possibly irreversible impacts poses risks. Adaptation is a necessary strategy at all scales to complement climate change mitigation efforts. Those with the least resources have the least capacity to adapt and are most vulnerable. Adaptation, sustainable development, and enhancement of equity can be mutually reinforcing.