IPCC Introduces New ‘Climate Change’ Definition Reflecting the
diversity of the communities involved in this assessment and
progress in science, several of the definitions used in this
Special Report differ in breadth or focus from those used in the
AR4 and other IPCC reports. Climate Change: A change in the
state of the climate that can be identified (e.g., by using
statistical tests) by changes in the mean and/or the variability
of its properties and that persists for an extended period,
typically decades or longer. Climate change may be due to
natural internal processes or external forcings, or to
persistent anthropogenic changes in the composition of the
atmosphere or in land use. [INSERT FOOTNOTE 2: This definition
differs from that in the United Nations Framework Convention on
Climate Change (UNFCCC), where climate change is defined as: “a
change of climate which is attributed directly or indirectly to
human activity that alters the composition of the global
atmosphere and which is in addition to natura