Definition 1
Climate Change means a change in the state of the climate that can be identified and that persists for [an extended period of time/ decades] and where the change is caused directly or indirectly by:
(a) human activity that alters the composition of the global atmosphere; and
(b) natural processes, including volcanic eruptions and changes of solar cycles.
Definition 2
Climate Change means a change in the state of the climate that can be identified and that persists for [an extended period of time/ decades] and where changes in the composition of the global atmosphere is caused directly or indirectly by an accumulated increase in Scope 1,2 and 3 anthropogenic Greenhouse Gas Emissions, which is in addition to natural climate variability.
Drafting notes and guidance
Changes to the climate system occur in the atmosphere, ocean, cryosphere and biosphere. Examples of climate change include major changes in temperature, precipitation or wind patterns, as well as changes in the risk of severe weather events occurring.
Option 1
This definition differs from that of the United Nations Framework Convention on Climate Change ( UNFCCC ), as it includes changes that result from natural climate variability. Legal agreements may consider the cause of climate change immaterial since the important point is that steps are taken to mitigate it and also reduce its impact (adaptation).
Those using this definition to draft national climate laws (where the causes of climate change may be more relevant) may want to adapt the definition to only focus on human-induced climate change.
Option 2
This definition is more akin to that of the UNFCCC, as it focuses solely on human-induced climate change and makes use of the categories of anthropogenic Greenhouse Gas Emissions – Scope 1, 2 and 3.