Energy and Global Warming
|Jun20-06, 05:48 PM||#1|
Energy and Global Warming
A new hypothesis for global warming
The current climate change/global warming debate has become highly political, with some people maintaining that the warming over the last 150 years is due to the enhanced greenhouse effect caused by anthropogenic emission of carbon dioxide and other gases from the burning of fossil fuels. However, there is some scientific opinion that the claimed increase in the concentration of carbon dioxide in the atmosphere is based on flawed data obtained from ice core measurements in samples from the Antarctic, with some alleged preferential selection of values having occurred, although this has been strongly disputed.
The principal argument for the enhanced greenhouse effect seems to be that climate models can be made to reproduce the observed warming only if the expected effects of the extra carbon dioxide are included in the models. If the carbon dioxide is removed, the models fail.
However, amid these claims and counter-claims, one fundamental consideration seems to have been omitted, and this is the effect of the vast amount of energy currently being generated by mankind. It is this energy itself which is causing the global warming. It is derived mainly from the chemical energy of fossil fuels, but whatever the source, the energy eventually ends up in the form of heat and as a change of state in melting some of the world’s ice, together with some inevitable losses to outer space.
Greenhouse gases are emitted, but this is simply a side effect which correlates with the amount of energy produced.
A simple new hypothesis is now proposed which depends only upon the most fundamental basis of Physics, namely the Law of Conservation of Energy, and in no way invokes the ideas of anthropogenic gas emissions.
It is suggested that the total energy generated by mankind eventually after use enters the atmosphere in the form of heat, as increased kinetic energy of the air molecules, and not as increased internal molecular excitation. Since oxygen and nitrogen have diatomic molecules and cannot absorb or emit radiation at the wavelengths concerned, this added energy cannot escape at this stage from the Earth’s system, and is transported as usual to the ice and snow covered regions of the world by the well-known mechanisms of atmospheric and ocean currents. Transport times taken to reach the poles are of no significance because no losses are incurred at this stage. Each individual area within those regions receives an amount of energy, by kinetic energy transfer by collision, in direct proportion to its surface area in relation to the total ice and snow covered area, and so melting of the ice can occur.
The circulation continues and some of the remaining energy can be transferred to the Earth’s surface, again by kinetic energy transfer by collision of the molecules. This warms the surface a little and so energy loss by radiation to outer space can now occur, but the temperature of the surface needs to rise by less than 0.1 deg C to dispose of the additional incoming energy, because of the fourth power temperature dependency of the Stefan-Boltzmann law. Some heat energy remains in the atmosphere and builds up over time, and this constitutes global warming, together with the melting of the ice.
With the Earth at a stable equilibrium temperature, the incoming solar energy is balanced by the outgoing infrared radiation, and so, although small by comparison with the solar energy, nevertheless the anthropogenic energy is important and it is more than sufficient to explain the observed effects, as will now be shown.
The values for world primary energy production are taken from the data published by the Energy Information Administration (EIA) of the United States government(1). The latest figure available is for 2003, and so it has been provisionally assumed that the figures for 2004 and 2005 are similar. This gives a value for current annual total world primary energy production of 417.12×10^15 BTU. This is equivalent to 4.4×10^20 Joules, in 1 year.
Taking the latent heat of fusion of ice to be 3.35×10^5 Joules/Kg, the mass of ice which currently can be melted in one year is 1.3×10^3 Gigatons, where 1 Gigaton (Gt) = 10^9 metric tons.
Comparison of hypothesis with estimated observations
This “total energy” hypothesis will now be supported by comparisons of mass of ice melted according to energy calculations with that estimated from practical observations.
From the NSIDC website(2) we find that the snow areas in the north have been very consistent from 1979 to 2001, and give a year round average of 22.5×10^6 Km^2.
The area of the Greenland ice cap(3) is 1.8×10^6 Km^2.
Small glaciers (North), area is 0.58×10^6 Km^2.
Arctic sea ice
Estimates of the area of arctic sea ice by the United States National Snow and Ice Data Center, Boulder, Colorado(4) show that at the end of the summer in 1978 the area was
7.7×10^6 Km^2, and 6.2×10^6 Km^2 in 2003. Thus, the average end of summer figure for this 25 year period was 7.0×10^6 Km^2. With the average winter area (5) of 15×10^6 Km^2, the corresponding yearly average area for this period has been taken to be 11.0×10^6 Km^2.
Thus, the year average total ice and snow area for the North is 35.88×10^6 Km^2, over the 25 year period.
Practical estimates of the ice draft(6) show that it has reduced from 3.1 m by about 40% in the last 30 years. Assuming linear rates of reduction for both the area and the thickness, this gives an estimated loss in volume of 8.0×10^3 Km^3 in this period from 1978 to 2003. The mass of ice melted is, therefore, estimated to be approximately 7.4×10^3 Gt in this period.
From the EIA data, we find that the sum of the world primary energy produced from 1978 to 2003 is 9.092×10^21 Joules.
The energy generated in the Northern hemisphere is assumed to be carried only towards the North, and similarly for the Southern hemisphere. Then the Northern primary energy is approximately 0.867 of the world total primary energy, based on data for 2000 taken from the EIA(7). Therefore, in the 25 year period being considered, 1978 to 2003, the total energy in the Northern hemisphere is 7.88×10^21 Joules.
The total energy entering the sea ice is then (11.0/35.88)×7.88×10^21 Joules, that is
2.42×10^21 J, and this can melt 7.2×10^3 Gt of sea ice. This is almost 3% less than the estimated practical figure of 7.4×10^3 Gt.
Greenland ice cap
A study by W. Krabill et al(8) of the changes in the Greenland ice cap between two series of measurements, one from 1993 to 1994, and the other from 1998 to 1999, gave a conservative estimate of 51 Km^3 for the average annual amount of ice lost during that period, which is equivalent to a mass of 46.8 Gt per year.
Calculations following the hypothesis show that the average mass of the Greenland ice cap which could be melted in one year during the same period is 57.1 Gt, which is 22% greater than the practical figure.
Clearly, the accuracy of the agreement between the hypothesis and practical figures cannot be taken too literally because of the difficulty of field measurement, particularly that of the thickness of the sea ice. This depends upon upward-looking sonar measurements by submarines under the ice, and there is a limit to the number of readings reasonably possible. Also, with respect to the Greenland practical estimate, it is not clear how much of the 51 Km^3 loss was due to melting and how much was due to calving, and escape of glaciers into the sea.
The total global area covered by the so-called “small glaciers”, that is glaciers which are not in Greenland or the Antarctic, is estimated to be 6.8×10^5 Km^2, of which the Northern hemisphere has 5.77×10^5 Km^2, and the Southern hemisphere has 1.03×10^5 Km^2. The current practical estimate of the amount of ice lost is 90 Km^2, or 82.5 Gt per year.
Calculations following the hypothesis give a figure of only 18.4 Gt of ice melted in 2003, which is a factor of about 5 in error. However, this may be due to the relatively small area of the glaciers compared with the amount of air circulating around them.
The temperature of the Northern atmosphere
From the EIA data and calculations following the hypothesis, it is estimated that the total energy in the Northern hemisphere summed over the 25 year period previously considered was 7.88×10^21 Joules, with the distribution as follows.
Arctic sea ice 2.42×10^21 Joules.
Greenland ice cap 0.40×10^21 Joules.
Small glaciers 0.57×10^21 Joules, taking the “practical” figure for melted ice.
Total energy into ice in North = 3.39×10^21 Joules, summed over 25 years.
Therefore, this leaves a 25 year “spare” energy balance in the North of 4.49×10^21 Joules.
Assuming that all this energy is taken up by the atmosphere, the temperature rise can now be calculated.
Taking figures of 2.55×10^18 Kg for the mass of the Northern atmosphere, and 1.015×10^3 J/Kg.degC for the specific heat of air, the temperature rise of the Northern atmosphere over the 25 year period is found to be 1.7 degC, compared with the observed figure of about 0.6 degC over the last 150 years. This excess will have been reduced by an associated increase in radiation to space.
The Antarctic ice sheet
Recently reported observations from the GRACE experiment give a figure of 152 Km^3 (or 139 Gt ) for the amount of ice which is currently being melted annually from the ice sheet. This requires 4.67×10^19 Joules per year.
From the EIA data for 2003, the total available energy in that year was 4.4×10^20 Joules.
We have previously taken the “geographic energy factor” to be 0.867 for the North, and so the proportion of the total energy going to the South is taken to be 0.133. This gives 5.85×10^19 J for the South in 2003. This is sufficient energy to melt the observed amount of ice, and leave a “spare” amount of energy of 1.18×10^19 Joules for that year.
The Antarctic troposphere
Recent work by BAS has shown that the temperature of the Antarctic troposphere has been increasing at the rate of between 0.5 degC and 0.7 degC per decade over the last 30 years.
Again from the EIA data, the total world energy for the decade 1994 to 2003 inclusive was 4.08×10^21 Joules. After applying the geographic factor of 0.133, this leaves 5.43×10^20 Joules in the South, for the decade. Since recent reports have shown a slight increase in the amount of Antarctic sea ice, it has been assumed that no net energy is entering the sea ice on average throughout the year, and so all this energy has been assigned in the calculations to the Antarctic ice sheet.
Assuming for the moment that the rate of melting of the ice is uniform at 139 Gt per year as in the previous section, the amount of energy required for the decade is 4.67×10^20 Joules. Hence, the “spare” energy for the Antarctic is (5.43 – 4.67)×10^20 Joules. That is 7.6×10^19 J for the decade.
Taking the area of the continent to be 14×10^6 Km^2, then the mass of its troposphere has been calculated to be 1.162×10^17 Kg, and so the spare energy above can produce a temperature rise of 0.64 deg C in one decade, in agreement with the observed figure.
The amount of energy being generated by mankind has been found to be in good agreement with that required to produce the effects observed both in the Arctic and the Antarctic. The energy is being obtained mainly from fossil fuels; it cannot be destroyed, but it can be taken up by the ice and snow by changing the state into water.
The concentrations of anthropogenic greenhouse gases emitted by burning fossil fuels may well correlate with the ice melting observations, but that is only to be expected since they arise from the energy production process, and it is simply no more than a secondary effect, a correlation but not a cause. Were this otherwise, the world’s energy budget would be exceeded by whatever amount came from the anthropogenic greenhouse gas effect, because sufficient energy is already available, as shown in this paper.
The suggested “total energy” hypothesis has not involved any consideration of anthropogenic greenhouse gases, but simply an application of the Law of Conservation of Energy. Therefore, no reduction of these anthropogenic gases will be able to solve the problem of global warming, which, indeed, must be occurring as evidenced by the melting of the ice. The warming is not yet particularly evident in other regions because much of the energy is being taken up in the ice melting process, and this will continue while sufficient ice remains.
It also follows that no benefit can be gained by switching to nuclear or geothermal energy, because the problem is simply one of the very energy being produced.
Therefore, the only way to solve the global warming problem is by changing completely to the use of “renewables”, solar energy, wind energy and possibly energy from the waves. Since this energy already exists, its use does not add to the total world energy, and so has no net warming effect.
(6) Rothrock, D.A., et al. Geophysical Research Letters 26(23): 3469-3472
(8) Krabill, W., et al, Science 289(5478): 428-430
Aubrey E Banner
Sale, Cheshire, UK
|Similar discussions for: Energy and Global Warming|
|Solutions to the energy crisis / global warming problem||Earth||10|
|global warming||Introductory Physics Homework||4|