Glossary and abbreviations - Climate Change: Biological and Human Aspects - page 534

Holocene The current interglacial, which began 11 700 years ago

( see Appendix 2).

Holocene climatic optimum A warm period (as opposed to a geological period) of

time some 8000-5000 years ago.

hyperthermal A geologically abrupt (that is, centuries to thousand

years in initiation) time of global warming leading to
a warm period that then lasts for scores of thousands
of years. Typically associated with a carbon isotope
excursion (CIE; see section 3.3.7).

ice age A period of time with glacials.

interglacial A warm period in an ice age between glacials.

interstadial A cool period within a (cool) glacial.

Ipswichian See Eemian.

Iron Age neoglaciation A minor glaciation that occurred 4500-2500 years

ago.

Laurentide Commonly used to describe the glacial ice sheet over

North America.

Little Ice Age A short cooling episode particularly associated with,

but not restricted to, the northern hemisphere approx-
imately around ad 1550-1850.

medieval climatic anomaly A short warming episode around approximately

ad 1100-1300, also known as the medieval warm

period

or (not preferred) the medieval climatic

optimum.

medieval warm period See medieval climatic anomaly.

metazoan Multicelled animal.

mitochondrion An organelle within a cell that consumes carbohydrate

and releases energy. Contains DNA that is inherited
through the female line.

nunatak A mountain peak poking through an ice sheet.

Oligocene The geological epoch lasting between 34 and 23 mya

( see Appendix 2).

opportunity cost An economist's term for the lost opportunity of

employing one investment (be it cash or a resource)
option over another (this topic considers resource
options). For example, some land used to grow biofuel
would have an opportunity cost of not being available
to grow food. Both options can also be quantified in
product and cash terms.

Pangaea A supercontinent existing in the deep geological past

that subsequently fragmented into Gondwana to the
south and Laurasia to the north.

Paramo A biome type in the tropical Andes, below the snow

line and above the tree line (it is also used to describe
similar environments elsewhere at and close to tropical
latitudes).