• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Explain why many scientists believe that human rather that natural causes may be more to blame for recent climate change

Extracts from this document...


´╗┐AS Geography Rosie Austin Explain why many scientists believe that human rather that natural causes may be more to blame for recent climate change (15 marks). Evidence of recent climate change is unambiguous. It is true that throughout history climate change has appeared to be cyclical, which we can see on a geological timescale, dating as far as 400 thousand years before present. This timescale shows that climate has always fluctuated as part of a cycle and in many years there have been some periods that are even warmer than the present. This scale shows higher than average temperatures on a long-term basis. A medium term, historical timescale also supports this as it clearly displays cooler and warmer periods, such as a medieval warm period from 1000-1400, and the ?little? ice age between 1400-1800.This trend occurred even before the industrial revolution. On studying a shorter term, more recent timescale however, it is clear that such a rapid increase in such a short period of time is an unprecedented phenomenon. The period from 1950-2000 in the northern hemisphere was the warmest 50 year period for 1,300 years, more notably so as such a rapid increase occurred in such a short space of time, whereas previously this change has taken place over thousands of years. It was during this period that 11 of the world?s hottest years occurred since 1850. ...read more.


Climate is affected mostly by two human activities; the enhanced greenhouse gas emissions and the destruction of the world’s natural CO2 sinks. The enhanced greenhouse effect is an extreme version of the earth’s natural greenhouse effect. Through this process, some of the sunlight that hits the earth is reflected back into space and some is reflected by the natural gasses (CO2, water vapour, methane etc.) that surround the earth back to the planet itself, having a warming effect. Without this greenhouse effect, the earth’s temperature would decrease by about 18°c and so this process is vital in the maintenance of our planet’s delicate environment. The enhanced greenhouse effect however is the increase in the effectiveness of the process due to an increase in the quantity of greenhouse gases in the atmosphere caused by human activities. This causes the gasses to reflect more of the sun’s rays back to earth as the layer of gasses is thicker, heating the earth further. There is evidence to show that the increase in greenhouse gasses has occurred since 1750, marking it simultaneously with the commencing of the Industrial Revolution. This would make sense as it was with the Industrial Revolution that the world saw the large scale burning of fossil fuels to provide energy for industrial activities. ...read more.


At this rate, 50-60% of Arctic ice could be lost by 2100. Approximately 1/3 of human generated emissions are stored in oceans, so with the melting of this ice a huge amount of CO2 is released into the atmosphere. Another example of a sink is plants, as they convert CO2 into organic matter and oxygen through photosynthesis, and are vital in maintaining the balance of gasses in the environment. Rainforests every year help to absorb almost 20% of manmade CO2 emissions; therefore deforestation can be classes as a major contributor to the causes of climate change. Cutting down rainforests faster than they can be replaced has a devastating effect on the carbon emission cycle, producing an extra 17% of greenhouse gasses. Agriculture has also been shown to produce significant effects on climate change, primarily through the production and release of carbon dioxide, methane and nitrous oxides which contribute to the greenhouse effect. Also, when agriculture alters the Earth?s land cover, it can change its ability to absorb or reflect heat and light. Land use change such as deforestation and desertification, together with the use of fossil fuels are the major anthropogenic sources of carbon dioxide. It is impossible to say however that these reasons are solely to blame for climate change, as there may be other factors that are unknown to us currently, and different scientists have different view to the extent that each factor contributes to this effect. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Atmosphere & Weathering section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Atmosphere & Weathering essays

  1. Marked by a teacher

    Discuss the relative importance of physical and human factors in accounting for changes to ...

    5 star(s)

    There have been many changes in the ecosystems of the British Isles due to increasing urbanisation. Due to the growth of urban areas, many cities have their own urban micro-climate which has an impact on the ecosystems within the areas.

  2. Marked by a teacher

    B)Explain why the amount of solar radiation absorbed by the earth's surface varies from ...

    4 star(s)

    The earth's tilt means that when the North Pole almost directly faces the sun it will have constant daylight, whereas the South Pole will be in complete darkness for almost the entirety of the day.

  1. To ehat extent is climate change a lot of hot air?

    Then, in 2007, there was an unpredicted change in global climate. It changed in a way that had been wholly unpredicted by the IPCC computer models. Global temperatures started to drop. Although CO2 levels are continuing to rise, after 25 years of temperatures rising, the world's climate was visibly starting to cool again.

  2. With rapid urbanization, increase in human activities is always regarded as the cause of ...

    The amount of vegetation decreases. Reduction in vegetation will lead to decrease in evapotranspiration rate. Less rainfall throughout the year will be resulted. Wind speed increases. With less vegetation absorbing carbon dioxide for photosynthesis, the carbon dioxide content in air is getting higher, trapping more heat and thus accelerates global warming.

  1. Outline the challenges and opportunities for human activity in present peri-glacial environments

    force the stones above them to rise until eventually they reach the surface. Both of these processes make the land difficult to plough and to be cultivated, as stones would have to be constantly removed from the land to allow for plant growth.

  2. The aim of this project was to investigate what differences exist in temperatures in ...

    Distance From Sea 4 mile Surface Gravel stones Shade None Shelter A few trees scattered around the car park Fort Widley to the north. These sites incorporate a few of the microclimatic variations that I want to include in my study, as well as being very similar to each other in longitude and situation.

  1. Global Warming causes are divided into two groups, natural and man-made causes

    They are: 1) Carbon dioxide emissions from power plants burning coal, natural gas or petroleum (oil) to produce electricity; 2) Carbon dioxide emissions from burning gasoline and diesel fuel for transportation; 3) Methane emissions from animals, agriculture such as rice paddies, and from Arctic sea beds; 4)

  2. Describe The Problem Of Global Warming

    The expanse of desert would increase. Low rainfall and rising temperature could add to the intensity and frequency of dusty storm. This in turn will immensely affect the quality of agricultural land, ultimately causing adverse effect on agricultural produce. It would have far-reaching socio-economic impact.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work