Climate change is happening, but is it down to humans or the work of nature?

It is now widely accepted that climate change is happening to some extent although it is not completely agreed on the pace of these changes. another widely debated area of climate change is that of its cause; whether it is man-made or natural. personally I think it is a combination of both. the earth’s climate changes ever so slightly over time due to how the earth’s axis ‘wobbles’ and also due to the slight elliptical orbit of the earth. however, it cannot be ignored that human causes have recently had an impact and could have added to these natural changes. For example, the world’s population is growing and has already reached 7 billion in the year 2014 and is predicted to grow to 8 billion by 2020 which means there is an increasing amount of energy resources being used to fuel the demands of this population, resulting in higher rates of pollution which contributes to the warming of the atmosphere. The debate over the causes of climate change has been driven by several key arguments and discoveries and at the moment is up to you to make up your own mind on what you think the cause is as there is so much conflicting evidence it is impossible at this stage to be 100% sure of a cause.

Greenland is largely covered by Ice and has mainly tundra conditions (photo credit: wwp.greenwichmeantime.com)

One argument for the natural cause of climate change is that there is evidence that the earth’s temperatures and climate naturally fluctuate over time. evidence from history is a good indicator of this as in the past, Vikings were able to settle and thrive in Greenland, which today has a much less favorable climate for growing crops and surviving. the change in climate since the settlement of the Vikings in Greenland suggests that there must have been some rapid change in climate which was likely to be from natural processes. The evidence that Vikings survived in Greenland is also supported by evidence that found that medieval Britain was also thriving agriculturally at this time, which was known as the medieval warm period, due to favorable climate conditions which suggests that the change was not just restricted to Greenland.  However, there is still much debate over whether Greenland was actually ‘green’ when the Vikings first settled. it has been suggested that it may have had a very similar climate as it does today and the reason it has been called ‘green’ was so that more settlers would be attracted over and so the evidence that climate was warmer than is uncertain to be true.

However, there is uncertain evidence to suggest that the medieval warm period even existed as many natural indicators of past climate conditions such as trees and coral reefs have shown no evidence that there was any significant change in the climate during this time and so therefore the medieval warm period didn’t actually exist, which undermines the evidence based on Greenland’s past. This has suggested that the warming we are experiencing today is due to human causes as it is more unusual.

sun spots on the sun are an indicator of solar activity (photo credit: crh.noaa.gov)

However some research has suggested that the sun’s variation in activity can cause the fluctuations we see in global temperature and this is indicated by the frequency of sunspots on the sun’s surface. sun spots occur most frequently when the sun is at its most active and there was a period of around 50 years in the 1800’s where there were no sunspots visible, hence indicating lower levels of solar activity. This period coincided which the so-called ‘mini ice age’ which was when a period of cooler temperatures led to more severe winters which led to the river Thames in London freezing over each winter during this period. therefore there is a link between the sun’s activity and the temperatures on the earth and so this suggests that the increase in temperatures may not be due to higher CO2 emissions but rather due to natural fluctuations in solar activity. however, recently the sun’s activity has fallen but the temperatures still continue to rise which suggests that the increase in temperatures is not due to natural events but due to human influences such as increasing CO2 levels in the atmosphere due to more industry and pollution.

Therefore there are several different arguments for supporting the idea that climate change is natural or supporting the idea that it is due to human activities. due to the conflicting arguments it is very hard to say for certain what the cause of climate change is so in the mean time this is largely down to your own individual opinion.

 

sources

  • Information of arguments for climate change being due to nature or humans sourced from BBC ‘Climate Wars’ series (first broadcast September 2008 on BBC2) presented by Professor Iain Stewart. Programme website: http://www.bbc.co.uk/programmes/b00djvq9
  • world population estimate in 2020 sourced from http://www.ifpri.org/sites/default/files/publications/vb5.pdf
  • information of the name of ‘Greenland’ sourced from:  http://en.wikipedia.org/wiki/Greenland#Etymology
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