As temperatures change, living things respond. They may either shift their range (the area of suitable climate and geography that they inhabit) or change the timing of certain temperature-dependent processes (e.g. flowering or egg-laying). Such shifts have now been observed in many species or communities. Examples include (from UNFCCC's Feeling the heat—current evidence of climate change):
In the Alps, some plant species have been migrating upward by one to four metres per decade, and some plants previously found only on mountaintops have disappeared.
In Europe, mating and egg-laying of some bird species has occurred earlier in the season—in the United Kingdom, for example, egg-laying by 20 of 65 species, including long-distance migrants, advanced by an average of eight days between 1971 and 1995.
Across Europe, the growing season in controlled, mixed-species gardens lengthened by 10.8 days from 1959 to 1993. Butterflies, dragonflies, moths, beetles, and other insects are now living at higher latitudes and altitudes, where previously it was too cold to survive.
The number of bleaching events on the world's coral reefs has increased strongly over the last two decades, and the combination of increasing acidity in the ocean
and higher sea surface temperatures
, both highly likely to increase further over the next half-century at least, will put more pressure on reefs.
Species shifts are of particular concern when they involve an increase in the range of vectors (e.g. disease-carrying mosquitoes) or pathogens.
Last reviewed 18 November, 2008 by the Parliamentary Library Web Manager
Images courtesy of AUSPIC