According to the Intergovernmental Panel on Climate Change (2015), climate change refers to a significant change in the measures of climate that persists for an extended time period. A global climate that is warming brings undesirable alterations that impact global water supplies, agriculture, the natural environment, human health and safety, as well as the systems of transportation. Climate change remains a major problem, largely because variations in climate pose a serious threat to both human societies and natural systems. The speed at which the current climate change is happening is however faster, and if corrective measures are not taken, warming of higher magnitude will be unavoidable, and the effects will be difficult to bear (IPCC, 2015). Climate change will make human life harder; people will most likely suffer from more erratic rainfall, heat waves, rising sea level, droughts, coastal erosion, and more severe hurricanes. With increasing climate change, crops, wild animals, domesticated animals, and natural vegetation will be unable to adapt, and this will undoubtedly undermine global food supplies (IPCC, 2015). While the effects of greenhouse gas emission are projected to be severe, human activities, coupled with solar variability, orbital variations, and volcanic activity are continually increasing the risk of climate change.
Causes of Climate Change
The climate of the Earth is shaped by a number of factors that operate at periods of between a few hours and millions of years. Some of the causes of climate change, such as orbital variations, solar variability, and volcanic activity, are natural (Hoffmann " Sgrò, 2011). However, human activities also significantly account for changes in climate. The realization of climate change as a major environmental problem has drawn attention to the impact of human activities on the world climate. Carbon dioxide emission as a result of deforestation and fossil-fuel combustion is a key mechanism through which human activities account for climate change. Human activities also produce other greenhouse gases, such as chlorofluorocarbons and methane; these often emerge from industrial processes and agricultural activities (Hoffmann " Sgrò, 2011). Besides, human conversion of vegetation through deforestation and agriculture is receiving increasing attention as a source of climate change. It is evident that clearing vegetation affects the carbon cycle, and as result, increases the amount of greenhouse gasses in the atmosphere. There is a consensus among scientists that the greenhouse gases affect the Earth’s radiation budget, resulting in climatic responses. In this light, climate records point to a clear trend of warming that extents the entire twentieth century to the start of the 21st century. In fact, the 2001-2010 period was the warmest decade in history (Hoffmann " Sgrò, 2011).
Orbital variations of the Earth around the sun also account for climate change. As Hoffmann and Sgrò (2011) elucidate, the orbit of the Earth around the sun is not circular but in the shape of an ellipse. This ellipse changes shapes; it is almost circular at sometimes or more pronounced at other times. When the ellipse is almost circular, the Earth stays almost the same distance from the sun as it rotates around its orbit. When the ellipse is more pronounced, the earth moves far away from the sun or closer as it orbits. When the Earth is much closer to the sun, the climate is warmer. However, orbital variations occur after a long period of time (between 100,000 and 413 years). With regard to volcanic activities, they affect the Earth’s climate through the dust particles and gases that go to the atmosphere during eruptions. When a volcanic activity occurs, the volcanic dust and gases may warm or cool the surface of the Earth dependent on how sunlight interacts with the particular volcanic material (Hoffmann " Sgrò, 2011). Besides, solar variability is another cause of climate change. In that, the brightness of the Sun has been gradually increasing over time since its formation (Hoffmann " Sgrò, 2011). As the brightness of the sun increases, it also changes the Earth’s climate.
Evidence in Support of Climate Change
The fact that the Earth’s Climate is changing cannot be disputed. Credible and strong scientific literature and evidence concludes that climate change is taking place, and at a much faster rate in the recent times. First, the historical trends in temperature readings that have been recorded from different places in the world indicate that the temperature is rising. As explained by the Intergovernmental Panel on Climate Change (2015), over the past century, the global average temperature has risen by nearly 1.5 degrees Fahrenheit, with more than half of the increase happening within the previous 35 years. In addition, long-term measurements of tide gauges, coupled with recent satellite data indicate that the global sea level is rising. It is estimated that the sea level has been rising at 0.12 inches per year for the last two decades (IPCC, 2015). Similarly, the Greenland and Antarctic ice sheets have been declining in size. Data from the National Aeronautics and Space Administration shows that Antarctica lost over 36 cubic miles of ice between the year 2002 and 2006, while Greenland lost nearly 36 to 60 cubic miles in the same period (IPCC, 2015).
Conclusion
Climate change is a major environmental problem that is of global concern. Based on the available scientific evidence, it is certain that human activities contribute to the issue of climate change through releasing greenhouse gases into the atmosphere. In turn, the oceans and the atmosphere have warmed, accompanied by the melting of polar ice and a rise in the sea water levels. This calls on concerted efforts among all the world nations to prevent climate change, or the effects will continue to intensify.
References
Hoffmann, A. A., " Sgrò, C. M. (2011). Climate change and evolutionary adaptation. Nature, 470(7335), 479-485.
Intergovernmental Panel on Climate Change (IPCC). (2015). Climate change 2014: mitigation of climate change. New York, NY: Cambridge University Press.
