The Effect Of Climate Change On The Tropical Savanna Grassland Biome: speech script”There’s one issue that will define the contours of this century more dramatically than anyother, and that is the urgent threat of a changing climate.” – Barack ObamaIt is common knowledge that climate change is a massive threat to our world, which isencompassed in the quote by former US-president Barack Obama. Consequently, seeing asthis is such a relevant issue in today’s society, I have decided on talking about the effectclimate change will have on our ecosystem, however in particular on the Tropical SavannaGrassland biome. To begin with, I would like to outline the different aspects that compose this particular biometo give you an idea of what the current situation is. As every geographer knows, the tropical savanna grasslands are located near the equator,between the Tropic of Cancer and the Tropic of Capricorn.
They cover much of Africa as wellas large areas of Australia, South America, and India.Furthermore, let’s talk about the climate. There is no such thing as a ‘typical’ savanna climate. According to Wladimir Köppen, this climate is classified as an Aw-climate, in other words atropical wet and dry climate. Rainfall in savanna areas ranges from about 500 to 2000mm peryear with a drought lasting between one and eight months.
In addition to this, due to the shortdistance from the equator and high insolation angles, the annual temperatures are high, in thiscase usually above 25 degrees celsius, as can be expected from a diurnal climate. Thesummers are hot and wet with occurrence of convectional rainfall. This wet period is a resultof the seasonal presence of the Inner Tropical Convergence Zone (ITCZ) during high-sunperiod, whereas winters are hot and dry due to the subtropical high pressure zone during lowsun period.
Moreover the high temperatures year-round mentioned earlier also lead to quitehigh evapotranspiration losses. Another important aspect worth mentioning is the soil in this biome. A majority of the soils inthis area are Alfisols and Ultisols. These soils are very old and low in fertility, but since thereis a dry season, more of the nutrients can stay in place.
Savanna soils are influenced bydistinct seasonal changes in processes. Moreover, they vary with topography. Frequentlysandy and leached soils predominate on the upper slopes, clay-based soils on lower slopes.
Additionally, further important elements in the constellation of this biome are the vegetationand organisms. Savanna vegetation is adapted to not only drought but also to fire. Grassespredominate on sandy, leached soils and are home to animals such as elephants, zebras, lions,hyenas and many more, while trees can be found in moister areas, such as valleys. Trees haveadapted to extreme weather cycles, wildfires and destructive grazing by elephants and underthese circumstances all but a few species of trees are kept from establishing. Now that we’ve covered the constellation this biome we can move on to the initial focus of my presentation: the consequences for the tropical savanna grasslands that will be caused by the growing issue of climate change.The main result that will endanger the quality of the savanna grasslands is desertification.
Firstly, due to the heightened greenhouse effect caused by excessive emission of harmful gases, in the absence of policies global average temperatures are estimated to rise 4.1 degrees to 4.8 degrees celsius by the end of the century. These warm temperatures will contribute to drying out the grassland savannas. Not only do the hotter conditions cause further drought but also the increase of carbon dioxide in the atmosphere. This leads to a greater tree dominance in the savanna and because trees require more water than grasses, the rivers and water holes will dry out more quickly. A further consequence of this is that the combination of severe drought and grazing by animals will lead to edible grasses becoming inedible and this is a great threat for many species and organisms living in this biome.
Due to the lack of sources for water an nutrition some of these species will most likely become extinct over time. Naturally the effects of climate change will bring great threats and destruction to the harmonious ecosystem of our earth. Therefore we must bring attention to the risks and consequences we will face if we don’t start taking responsibility for our mistakes and start trying to improve the world we live in for ourselves and future generations. I would like to end my presentation with a quote that as far as I’m concerned, sums up the gist of my statement. I certainly adopt the viewpoint of Jim Yong Kim when he says “We have to wake up and face the urgency of the now”Ladies and gentlemen, fellow geographers, I thank you for your attention.