Global warming: the result of the industrial burning of fossil fuels?

Helen Hearson

Geol 1011

The ‘greenhouse theory’ as a model of how the earth maintains a balance of heat was first proposed by Arrenhius in 1896,(as cited in Seidal). The greenhouse theory is that a number of ‘greenhouse gases’ (GHG) are present in the earth’s atmosphere. These gases allow ultraviolet and visible radiation to penetrate and warm the earth, and then absorb infrared radiation emitted by the earth, and acts as a thermal blanket, trapping this heat in the atmosphere. Without the greenhouse effect the earth’s surface temperature would be around 50oF cooler than it is today (c.ref.5). The earth’s surface temperature is currently rising, having seen a rise of approximately 0.5oC in the past hundred years (c.ref 5), and expected to rise by 2.5oC by 2050, and 5oC by 2100 (Siedal & Keyes, 1983; EPA, 2003, c.ref 6). The last 10 warmest years in the past century have all occurred in the last 15 years, the hottest being 1998, which was warmer than the long-term average by around 0.66oC (National Oceanic and Atmospheric Administration, c.ref 1).

The result of this global warming is predicted to be an increase in precipitation, more dramatic weather conditions, and a rise in sea levels, with a rise of 4-8 inches already seen over the past century (EPA c.ref 6). El Nino has increased in frequency from once every 5-7 years, to once every 3-5 years (Showstack, 1988, c.ref 1). The ice caps are shrinking, with a 3,000km2 section of the Larsen B ice sheet in Antarctica disintegrating in just 35 days (National Snow and Ice Data Center, c.ref 4), which is indicative of the warming of the atmosphere, (Gelbispan, 1997, c.ref 1). No one seems to deny climate change is occurring, it is the cause that is the subject of debate. The Kyoto Protocol has suggested that it is primarily a result of anthropogenic contributions, primarily the burning of fossil fuels, and many views previously supported this hypothesis. However it has been met with some strong opposition.

The argument that the cause of global warming is a result of human industrial burning of fossil fuels is due to the rapid and considerable increase in emissions of GHG since the industrial revolution- it is sensible to assume that such a large increase could not occur without consequence. These gases are thickening the thermal blanket around the earth, letting less heat escape and resulting in a net warming or the whole earth. The GHG we are pumping into the atmosphere is upsetting the earth’s natural balance.

The main GHG’s concerned are carbon dioxide, methane, nitrous oxide and indirectly ...

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The main GHG’s concerned are carbon dioxide, methane, nitrous oxide and indirectly CFC’s. The primary source of CO2 emissions is the burning of fossil fuels used for electricity, fuel for cars, heat houses and power industry, caused by its incomplete combustion. Fossil fuels burning accounting for 98% of the US emissions of CO2, 24% of methane emissions, and 18% of NO emissions (c.ref 1). With the increasing use of fossil fuels, atmospheric CO2 concentrations have increased 30% (from 280ppm to around 360ppm1), CH4 concentrations have doubled, and NO concentrations have increased by 15% (c.ref 6).

In 1980’s 5.5bn tons of CO2 were released into the atmosphere annually due to the burning of fossil fuels, and 1.6bn tons released due to deforestation and changes to use in land (c.ref 1). It’s thought that the ocean takes up around 2bn tons, and an as yet unidentified sink takes up 2bn, leaving still 3.2bn tons, which supposedly must be released into the atmosphere (c.ref 1). The argument is that this rapid increase in CO2 emissions has upset the earth’s natural carbon cycle, which regulates the amount of CO2 in the atmosphere, and is consequently influential in the earth’s temperature regulation

Opposition to global warming is argued to have an underlying political agenda. Fossil fuels are vital for industry and everyday life. To reduce use of fossil fuels would mean a complete overhaul of industry. The conversion of industry and everyday things such as vehicles would be time consuming, very costly and effortful, requiring a compete overhaul of industry. Therefore it is beneficial for industry and governments to play down the issue of global warming, in the same way that cigarette companies played down the link between lung cancer and smoking, with the consequences being much worse than a cancer epidemic.

The opposing argument in global warming is that it is simply part of the natural cycle of the earth’s climate. There has been hot periods on earth, and ice ages, just as we have seen periods of high levels of CO2, therefore the argument stands that global warming would occur regardless. 90bn tons of CO2 circulate between the earths ocean and atmosphere, and a further 60bn tons exchange between vegetation and atmosphere, which is over 95% of all atmospheric CO2 (IPCC, 1995 c. ref.3), therefore the 5-6bn tons due to human activity is an insignificant amount, and not enough to upset the earth’s balance, although some scientists disagree and maintain that any difference, no matter how small can upset the balance. Essenhigh turns the whole notion of global warming on its head, saying that it is an increase in temperature that is causing an increase in CO2 (c.ref 3). Shackleton & Opdyke (1973) (c.ref 3) argued that global temperature has been oscillating steadily, rising gradually over the last million years, with the amplitude of periodic oscillation increasing from 5 to 10oC over the last 100,000 years, we’re simply near a peak that started 25,000 years ago.

The Arctic Ocean Model (Calder, 1974 c.ref 3) postulates that the arctic ocean acts as a temperature regulator, when frozen it prevents evaporation that would return as snow and replenish the ice cap, resulting in its shrinkage, which is where it is believed we are in the cycle today. When the ice cap melts the earth warms, evaporation can occur, which returns as snow and replenishes the ice cap, resulting in a colder global temperature and we enter an ice age. According to this model we could reach its peak within the next 10-20 years, resulting in another ice age.

Balling (c.ref 5) argues that we are an urban heat island, and measurements of earth surface temperature cannot be indicative of what is happening globally as the earth is 75% water. If global warming is occurring primarily due to fossil fuel burning and GHG concentrations in the atmosphere, the kinds of increases we have seen should result in higher temperature increases than we are seeing. Therefore, CO2 concentrations are increasing, and may have an affect, but it is not the chief cause of climate change. Balling argues that we are emerging from a “Little Ice Age” and that the earth was warmer, but began to cool in 1600, therefore is we are emerging from the little ice age we would expect a global temperature increase (c.ref 5).

To conclude, the earth has had a turbulent climatic history, ice ages and hot periods. Most people consider the last 2,000 years to have been uncharacteristically consistent, therefore a temperature rise would only been in character with normal patterns of variation. The burning of fossil fuels and the effect on atmospheric GHG concentrations cannot be completely ignored as a contributing factor to global warming, as any upset in the equilibrium of the earth cannot be underestimated. As the chief cause of global warming industrial use of fossil fuels seems highly unlikely

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