|Essay: Climate Change
‘Up and down, up and down- that is how temperature and climate have always gone in the past and there is no proof they are not still doing exactly the same thing now. In other words, climate change is an entirely natural phenomenon, nothing to do with the burning of fossil fuels.’ (David Bellamy). Discuss the extent to which you agree with this statement.
Climate can be described as the long term prevailing weather conditions of an area, the key words being ‘long term’. David Bellamy’s statement, suggests that those who disregard the ‘natural’ theory should study the data from thousands of years ago to see that a continuous pattern is shown. However, perhaps Bellamy needed to study the most recent cycle in the past 40 years in more detail to see that global temperature change is not following its usual course but has in fact been increasing at nearly four times the pace. Whether anthropogenic or natural, some factors must have changed in order to cause such a large difference. It would be foolish to believe climate change is one hundred percent natural or totally anthropogenic as it is evident that climate fluctuations have always been present, but have been amplified by recent anthropogenic changes.
A natural theory is based on the amount of solar energy emitted to earth. In past cycles, the amount of solar input has fluctuated and was the cause of the Little Ice Age between 1600 and 1800 and glacial advancement in the Alps. However, since 1800, there has been very little or no change in solar output, yet the earth is still warming. In addition, if the sun had become more active, warmer temperatures would have been found through all layers of the atmosphere, while instead, the upper atmosphere has cooled and the lower parts have warmed. This suggests solar irradiance is not the only contributing factor to global climate change. However these atmospheric temperatures may have been affected by anthropogenic increases of greenhouse gases.
Greenhouse gases play a vital role in controlling the earth’s temperature. A blanket of gases, primarily water vapour and small amounts of carbon dioxide, methane and nitrous oxide, surround the earth. Half of the sun’s light energy reaching earth passes through the air and clouds to the surface, where it is radiated upward as infrared heat. Roughly 90% of this infrared is trapped by the greenhouse gases and is warmed to a life-supporting average temperature of 15 degrees Celsius. This balance of gases has been affected by anthropogenic actions, especially since the industrial revolution, where increasing amounts of carbon dioxide especially, have been released from the burning of fossil fuels, and are causing more of the radiation to be trapped in the earth’s atmosphere causing an overall warming. It is possible to find fault in this theory as, although there has been an overall global increase in temperature, some areas on earth have actually deceased in temperature, with no scientific evidence showing the reason for this. The greenhouse effect is probably the most accepted theory of climate change, which disputes David Bellamy, but there are still some gaps in this theory.
Another debate explores the impact of ocean and seas. They play a large role in the global climate system and have the capacity to carry a large amount of heat which can drastically affect climate conditions. At the same time, the increases in carbon dioxide levels also have an impact on seas and oceans and are causing them to become more acidic. These changes along with others cause temperatures and ocean currents to change and can affect both short and long term weather. These effects have already been seen in 2011 with severe flooding in Australia and Brazil due to colder water currents in the Pacific Ocean.
When David Bellamy says ‘natural’ does he include the effects of natural hazards, such as volcanic eruptions? Are they included in the natural cycle he refers to? Volcanic eruptions have the ability to dramatically cool the planet on a long term basis, as the release of large volumes of gases, mainly sulphur dioxide and reduce the amount of sunlight reaching the earth.
It seems that trying to point the finger at just one individual factor for causing climate change is currently nearly impossible. There are such obvious links showing that while natural factors may contribute, they can be made worse by anthropogenic factors, and vice versa. The earth relies on a very fine balance between the amount of radiation, the temperature and gases in the atmosphere for example, so although one factor may have more obviously tipped the balance over, there are too many factors to select one individual cause.