Twenty-eighth Report Adapting Institutions to Climate Change Cm ...

Appendix A
Mitigation – an anthropogenic intervention to reduce the anthropogenic forcing of the climate
system; it includes strategies to reduce greenhouse gas emissions and enhancing greenhouse
gas sinks.
Invasive species and invasive alien species – a species aggressively expanding its range and population
density into a region in which it is not native, often through out-competing or otherwise dominating
native species. (c.f. alternative definitions below.)
Planned adaptation is the increase in adaptive capacity by mobilising institutions and policies to establish
or strengthen conditions favourable for effective adaptation and investment in new technologies and
infrastructure. (Taken from IPCC WGII AR4 Section 5.5, c.f. alternative definition above.)
Resilience – the ability of a social or ecological system to absorb disturbances while retaining the same
basic structure and ways of functioning, the capacity for self-organisation, and the capacity to adapt to
stress and change. (c.f. alternative definition below.)
Threshold – the level of magnitude of a system process at which sudden or rapid change occurs. A
point or level at which new properties emerge in an ecological, economic or other system, invalidating
predictions based on mathematical relationships that apply at lower levels.
Threshold – this marks the point where stress on an exposed system or activity, if exceeded, results
in a non-linear response in that system or activity. (Taken from IPCC WGII AR4 Section 2.3.1, c.f.
alternative definition above.)
Impact threshold – a level of change in condition, measured on a linear scale, regarded as ‘unacceptable’
and inviting some form of response. In the case of an impact threshold, the response is the non-linear
aspect; for example, a management threshold. Exceeding a management threshold will result in a change
of legal, regulatory, economic, or cultural behaviour. (Taken from IPCC WGII AR4 Section 2.3.1.)
Systemic threshold – a non-linear change in state, where a system shifts from one identifiable set of
conditions to another. A systemic threshold can often be objectively measured. (Taken from IPCC WGII
AR4 Section 2.3.1.)
Vulnerability is the degree to which a system is susceptible to, and unable to cope with, adverse effects
of climate change, including climate variability and extremes. Vulnerability is a function of the character,
magnitude, and rate of climate change and variation to which a system is exposed, its sensitivity, and its
adaptive capacity. (c.f. alternative definition below.)
Definitions from sources other than the IPCC
Alien species – a species, subspecies or lower taxon, introduced outside its natural past or present distribution;
includes any part, gametes, seeds, eggs, or propagules of such species that might survive and
subsequently reproduce. Some international/regional/national instruments use the term ‘exotic species’,
‘non-indigenous species’ or ‘non-native species’ when referring to ‘alien species’. (Taken from ‘Developing
an EU Framework for Invasive Alien Species – Discussion paper’.)
Alien species – a species, subspecies or lower taxon introduced outside of its natural range (past or
present) and dispersal potential (i.e. outside the range it occupies naturally or could not occupy without
direct or indirect introduction or care by humans) and includes any part, gametes or propagule of such
138