Organisms Response to the Increases in Extreme Weather Events

AN ORGANISMS RESPONSE TO THE INCREASES IN EXTREME WEATHER EVENTS

The global climate has increased by approximately 0.6°C over the last 100 years (Walther et al. 2002). This increased rate of changes is largely due to humans: the industrial revolution, the advancement of technology and burning of fossil fuels (Timmermann et al. 1999). This human involvement has gradually changed the natural order of the environment and many of its processes. Some of these environmental conditions are not easily predictable, as these climatic changes are also increasing more extreme weather events such as: droughts in the savannah country, floods in low lying areas and an increase in intensity of cyclonic events (Knutson et al. 2010).

Human interactions with tropical forests in particular are influencing the nature of these forests. Many tropical forests mitigate warming through evaporative cooling, which is the idea of a stable ecosystem. A large-scale conversion of forest to pasture creates a warmer, drier climate (Bonan 2008). Deforestation for crops or roads is creating edge effects in the forests. Some of these tropical areas around the globe will also receive an increase in rainfall over many parts of the tropics (Legates et al. 1990). With this added rainfall and higher average temperatures some tropical rainforests would show an increase in forest cover. Allowing greater growth or an alteration in biodiversity and tropic levels within these stable, tropical environments (Petchey et al. 1999).

With this evolutionary rapid increase in temperature many organisms must alter their responses faster than previously needed. Reacting to rapid or slow changes depending on the environmental conditions, for example using behavioural thermoregulatio...

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... with the remaining forest being refuge areas for surviving species (Haffer 1969). Especially on the land surrounding the equator between the Tropic of Capricorn and the Tropic of Cancer, also known as the tropics (Pidwirny 2006).

More recently scientists have predicted a global increase in temperatures as tropical ecosystems are sensitive to small changes in temperature, species distributions are likely to shrink, not allowing enough time for the species to respond (Townsend et al. 1992 & Williams et al. 2003). With climate change the tropics are experiencing more unpredictability with future rainfall and tropical cyclones (Henderson-Sellers et al. 1998 & Hughes 2003). Tropical cyclones have been modeled with increasing temperatures; it was found that the intensity of the cyclones will increase but uncertainty in the frequency of events (Knutson et al. 2010).