Climate Change

Monday, August 14, 2006

GLOBAL CLIMATE CHANGE & THE FLORA OF SOUTH AFRICA

Global climate change, I believe should be and are already on top of the international agenda. With the hunger and thirst that we as humans go after fossil fuel to sustain our daily livelihoods, we actually just shaping the environment to something different that it has been the past billion years. We are rapidly increasing greenhouse gas concentrations, with some climate models predicting a rise in temperature of 1.5 – 4.5° Celsius causing the Earth to warm up(Rowlands 1996). The concentration of Carbon Dioxide is set to exceed the 500 part per million in the year 2050 which might cause great natural disasters (Midgley and other 2002).

The economy of South Africa is an exceptionally energy demanding one (Rowlands 1996). In particular, we thrive on carbon in the form of coal. The country contains one of the world largest reserves of coal and this source has provided and still contributes 90% of the electricity for the 46 million people. Coal is reasonably cheap in comparisons with other energy sources; subsequently this source makes South Africa a fair contributor to global climate change. On a list for countries contributing to global climate change, South Africa embraces the eighteenth spot with emissions per capita being above the global average (Rowlands 1996).

Mzanzi are blessed with over 21 000 unique and indigenous plants that gives us pleasure to watch, to atlas and for some they provide bread and butter (Midgley and other 2002). Information from the Hadley Centre for Climate Prediction and Research in the United Kingdom forecast by the year 2050 the country will be warmer and drier than today. Based on the assumption that CO2 will increase to 550 ppm towards 2050, the temperature in January will increase mostly in the central interior and Northern Cape (2.5 - 4.5° C) and least at the coast (0.5 – 1.0° C) (Midgley and other 2002). The Western Cape is expected to lose approximately 25% of its winter rainfall with massive implication on agriculture and already water scarce province.

The vegetation types throughout South Africa are impacted by the climate. The highveld grassland are sustained by winter frosts. The two most diverse and unique floral regions, the Fynbos and Succulent Karoo Biomes originated with the help of the winter rainfall of the Western Cape/ West Coast. Just look at the difference in vegetation types between that in the Great Karoo and evergreen forests of the Southern Cape. The differences between them are regulated by the annual rainfall. By using climate predictions from the Hadley Centre the distribution patterns of seven biomes of South Africa can look like the following in 2050.

The succulent Karoo biome will the most affected as only the tougher of the succulents will be able to occupy this region. The flora of the succulent Karoo will tend to migrate southwards and the only viable region in 2050 pending on climate, will be the Agulhas Plain. The Fynbos biome are set to lose a large number of species, but the borders however will remain the relatively the same like it is today. The Fynbos biome is already restricted to the mountains of the Western Cape, which will provide refuge to some species to move up or down into different microclimates. Large portions of the Fynbos vegetation are also near the coast, meaning that warming of these areas will be much slower than the interior part of the country (Midgley and other 2002). The remaining biomes will also tend to move eastwards according the Hadley Centre which will result in competition, invasion and worst of all extinction.

Even though climate plays a pivotal role in the distribution of plants, it is not the only factor, as soil type, ecological interactions, fire, pest and grazing pressure limit the distribution of our flora (Midgley and other 2002).

Reference:

Midgley G, Ashwell A, Rutherford M, Bond W, Hannah L, Powrie L. 2002. Charting Uncertainty: Global climate change and its implications for our flora. Veld & Flora 88(2): 70-72.

Rowlands IH. 1996. South Africa and Global Climate Change. The Journal of Modern African Studies 34(1): 163-178.

PLAGIARISM DECLARATION
1.I know that plagiarism is wrong. Plagiarism is to use another’s work and to pretend that it is one’s own.
2. I have used the CSE/CBE convention for citation and referencing. Each significant contribution to, and quotation in this project from the work, or works, of other people has been attributed, and has been cited and referenced.
3. This assignment is my own work.
4. I have not allowed, and will not allow anyone to copy my work with the intention of passing it off as his or her own work.

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