Climate change hastens population extinctions Essay

Climate change hastens population extinctions - Essay Example Literature review: The climate system is a complex, interactive system consisting of the atmosphere, land surface, snow and ice, oceans and other bodies of water, and living things. Climate is usually described in terms of the mean and variability of temperature, precipitation and wind over a period, ranging from months to millions of years (the classical period is 30 years). Global warming the most visible aspect of climate change affects our whole climate system including humans worldwide. In the past three decades the EL Nino effect in the Southern hemisphere has become more intense, causing greater variation in rainfall. . North America and Central Asia will warm more than the oceans or coastal regions. Precipitation will increase overall, but there will be sharp regional variations, with some areas that now receive adequate rainfall becoming arid. The consequences for non-human animals and bio-diversity will also be severe. In some regions plant and animal communities will gradually move further from the equator, or to higher altitudes, following climate patterns. Australia's unique alpine plants and animals already survive only on the country's highest alpine plains and peaks. If snow ceases to fall on their territory, they will become extinct. Similarly, many species are also shifting towards favorable climatic zones or facing threats of extinction. One such species is Checkerspot butterfly. Recent studies are pointing out that climate change may be one of the factors for extinction of species but not the sole reason. Therefore, the detection and attribution of climate change in natural system has been a challenge for climate change biologists. Assigning climate change as the cause of the observed biotic changes has often had a deeper basis, such as a known mechanistic link between climate variables and biology of the study of species (Parmesan et al. 2000). On a continental scale, movements of the entire species ranges have been found in butterflies in both north America and Europe, where two thirds of the 58 species studied have shifted their ranges northward (Parmesan, 1996; Parmesan et al. 1999). Seventy years of published studies document the limiting effects of temperature on butterfly population dynamics, particularly at northern range edges (Parmesan, 2003). The northern boundaries of many European butterflies are correlated with summertime isotherms (Thomas, 199 3). Montane studies are lesser in numbers and less documented but these shows upward movement of species in general. In one of the studies, Parmesan (1996) found that Edith's Checkerspot butterfly has shifted upwards by 105m in the Sieara Nevada Mountains of California. Now apart from warming impacts, the difference in rainfall has some impact on movement/extinction of species/plants. In one of the study, at sites in Alaska, more recent decades have been relatively dry, which is believed to have prevented trees from responding to current warming as they did before (Barber et al., 2000) Precipitation changes may also be the reason for shifting/extinction. Recent trends toward increased precipitation have seen to be driving vegetation compositions to be altering the relative abundances of species within Rodent, reptile and ant communities (Brown et al. 1997). Theory indicates that a