Our earth has undergone extreme climate change in the form of the theory of global warming in recent years. Average temperatures have increased by 1.8°C since 1880 and while some blame it on the influence of human activities, others believe that climate change is purely natural and humans have insignificant effect on its cause.

The greenhouse effect occurs when greenhouse gases trap heat in the atmosphere to increase average temperatures. This phenomenon is exacerbated by improper agricultural practices especially characteristic of Less Developed Countries (LDCs). In the Kalimantan rainforest of Indonesia, Sumatra, slash-and-burn agriculture is predominant and due to excessive, constant burning emitting carbon dioxide, this has largely increased the amount of greenhouse effect occurring over Indonesia. Humans here have managed to exert so large an impact that the original tropical climate with abundant rainfall has now been reduced to hot,baked farmland with sparse rainfall, averaging 32°C. Had agriculture been carried out sustainably without such environmentally harmful burning, temperatures over Sumatra will definitely not increase so much, unlike the rest of Indonesia with an average of 28°C. In this case, humans definitely are the main influence of climate change.

However regarding the above point, humans may be limited in their effects as well, as urban microclimates usually do not reflect the regional or even national climate as in Indonesia’s case. Extremely hot and drought-like conditions exist mainly in Kalimantan and over Sumatra where slash-and-burn practices occurs, however extending the scope to Java, Bandung and most of Indonesia, temperatures have not been noticeably altered. Needless to say, where global temperature change is concerned, intense carbon emissions over Sumatra alone will not exert significantly large effects.

Human activity also comes in the form of urbanization which involves the industrial revolution which has been taking place since the late 19th century. Today the burning of fossil fuels and consumption of coal and other natural resources for energy to power industrial activities and economic development have reached an all-time high, more than doubling since the 1990s. Such human activity in countries like China, the world’s largest burner of coal, has contributed to 34 billion tonnes of carbon emissions in 2011, also the world’s largest carbon emission per capita.

This has proven to be a main cause of global warming within China, especially industrial hotspots like Shanghai and Beijing. While it is true that human activity may seem limited in effects as there are no records to show that average temperatures in China are increasing, recent evidence of earlier spring blooms, increasingly humid summers, milder winters and extreme local flash floods show that it is very possible that human activity has been causing an incremental, significant effect to climate change.

Looking at natural factors, climate change is not affected by humans only. Volcanic eruptions that occur periodically over consistent recurrent intervals emit sulfur dioxide, ash, cinder and particulates that act as heat-absorbing nuclei to increase average temperatures. However this does not hold as contrary to belief, volcanoes have a cooling influence in the long-term. Sulfur combines with water vapor in the stratosphere to form dense clouds of tiny sulfuric acid droplets. These droplets take several years to settle out and they are capable of decreasing the troposphere temperatures because they absorb solar radiation and scatter it back to space.The 1991 Mount Pinatubo eruption in Philippines produced the largest sulfur oxide cloud in history. The combined aerosol plume of Mt. Pinatubo and Mt. Hudson diffused around the globe in months. The data collected show that mean world temperatures decreased by about 1°C over the subsequent two years. Also, scientists estimate that human activity emits 150 times more carbon dioxide than volcanoes annually. Thus ascribing the blame to natural factors is not valid in the long-run.

Perhaps the more valid natural reasoning would be evidence that shows that earth undergoes a natural 1500-year cycle of alternate warming and cooling. Experts postulate that warming has been occurring since 1824 as greenhouse gases and air has been found in polar icebergs. The HMS challenger plunging to 300m deep and covering about 300 oceanic regions found that ocean surface temperatures have rose 0.59°C since the 1870s, indicating that global warming had occurred hundreds of years earlier than expected before the industrial revolution. Human’s effects seem to be limited here.

In conclusion, I disagree that human activities have only limited effects on climate. While it may be true that climate change is a natural process involving negative feedback of the earth’s regulating mechanism, it is definitely exacerbated severely by humans who provide excessive amounts of greenhouse gases and chemicals extremely conducive for this process to be heightened at unprecedented rates. Should humans have moderate carbon footprints and burn natural resources at reasonable rates, climate change would not be affected by such an increase in its speed.