Whatever the causes (be they man-made or natural or both) there is certainty about the fact that climates are changing around the world, and when these changes lead to increased temperatures or altered patterns of rainfall animals (and plants) all need to react if they are to survive.
Consensus on Climate Change in Australia
In 2007 the Intergovernmental Panel on Climate Change (in Australia) released a formal report which stated that:
- Warming of the (Australian) climate system is unequivocal
- Humans are very likely to be causing most of the warming that has been experienced since 1950
- It is very likely that changes in the global climate system will continue well into the future, and that they will be larger than those seen in the recent past.
These changes have the potential to have a major impact on human and natural systems throughout the world including Australia.
The report goes on to give specific examples of the effects:
- the frequency of hot days and nights has increased and the frequency of cold days and nights has declined
- south-western Australia has had less rain, but north-west Australia has become wetter (since 1950)
- global sea levels rose by 17 cm during the 20th century, and by 10 cm (from 1920-2000) in Australia.
The full technical report can be viewed to look at the details.
This is just one example of the way that climate changes are being monitored around the world – but what effect does this have on plants and animals?
Wildlife and Climate Change
Scientific American reports that a study (looking at the effects on over 2,000 species) concludes that they, "are responding up to three times faster to climate change than previously estimated, as wildlife shifts to cooler altitudes and latitudes", but the study mentioned (Science) notes that individual species vary greatly in their rates of change, and that average shifts derive from a wide diversity of responses by individual species.
The University of York (reporting on the same study) goes on to point out that, "these changes are equivalent to animals and plants shifting away from the Equator at around 20 cm per hour, for every hour of the day, for every day of the year", and that, "this has been going on for the last 40 years and is set to continue for at least the rest of this century”.
Some species of butterfly in the UK (for example the high brown fritillary) have declined in numbers due to habitat loss, while the comma butterfly has moved 220 kilometres northwards in two decades (due to a warming of the climate in Britain).
Previous studies suggest that climate change represents a serious extinction risk to at least 10 per cent of the world’s species, and this study points out that, "many species may indeed be heading rapidly towards extinction ... but on the other hand, other species are moving to new areas where the climate has become suitable ... there will be some winners as well as many losers.”
In order to be able to understand how plant and animal populations might change (on land and at sea), and to learn enough to manage habitats efficiently, much research is needed. It is no good looking at any one species in isolation, the full range of interactions in each habitat need to be taken into account.
This is an enormous task, and time is running out!
Sources:
- ' Wildlife Responds Fast to Climate Change ', Deborah Zabarenko, Scientific American, August 2011.
- 'Rapid Range Shifts of Species Associated with High Levels of Climate Warming', Chen, Hill et al., Science, August 2011.
- 'Further, faster, higher', Chris Thomas, University of York, August 2011.
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