Man clearly makes a contribution to global warming because there is a strong local warming effect in urban areas. However, the contributions of man to warming on the global scale are small and difficult to even measure. The anthropogenic global warming catastrophe hypothesis makes the following claims:
- Man's use of fossil fuels results in CO2 emissions in amounts significant compared to the natural sources.
- The CO2 added by man to the atmosphere lingers there a long time, often said to be 100 years.
- The greenhouse gas warming caused by these additions of CO2 is itself significant.
- The warming caused by man's CO2 additions to the atmosphere causes a much stronger warming due to increased water vapor at altitude and its greenhouse effect.
- The great increase in water vapor at 8 to 12 km altitude over the equator and the lower latitudes results in a warming hot zone in the atmosphere, which warms the entire globe by back infra-red radiation.
- The resulting warming causes catastrophic effects, such as droughts, heavy rains, low snowfall, heavy snowfall, increased numbers and severity of hurricanes and typhoons, increased malaria, increased parasites, a greater mortality of older people, the extinction of species, and a great rise in sea level.
This is all so much hogwash and bunkum. Let us consider some of the reasons why CO2 emitted by man is not causing such large and significant global warming effects:
1) The rise of atmospheric CO2 concentrations since 1850 to the level of 2008 made almost no difference in the infra-red radiation absorbed since almost all of the infra-red radiation was already being absorbed that CO2 can absorb in 1850. The temperature increase due to the CO2 increase since 1850 is about 0.12C. This is based upon the usual atmospheric CO2 concentration plot, but like the temperature hockey stick plot, this plot is now known to have been manipulated to make the rise of CO2 since the end of the Little Ice Age and the start of the Industrial Revolution look more dramatic than it really has been. It has not been proven that the general rise in CO2 is not simply due to the oceans warming as their temperature increases slowly due to the end of the Little Ice Age just as often happened before the Industrial Age.
2) The greenhouse gas models treat the Earth's surface as a black body thermal radiator. Black body radiators are a very special idealization which the surface of the Earth does not much resemble. Real objects are characterized by an emissivity constant of less than 1. The black body radiator has an emissivity of 1. The Earth's surface has an emissivity of about 0.7. The diagram above says surface radiation is 396 W/m^2, which is the power emission for a black body with a temperature of 289.1K, close to the Earth's average surface temperature. The real Earth's surface with an emissivity of 0.7 only emits about 277.2 W/m^2 at a temperature of 289.1K. The Kiehl - Trenberth diagram over-estimates the outgoing surface radiation by a factor of 1.43.
3) The models underestimate the solar radiation incident on the Earth's surface. They claim it to be about 47% ( Kiehl and Trenberth), when measurements have commonly shown it to be between 65 and 75% of the total solar radiation incident upon the outer atmosphere (see the diagram below). This underestimate of incident radiation, together with the much higher surface radiation claimed by treating the Earth's surface as a black body radiator, allows them to greatly increase a claimed large amount of back radiation due to infra-red absorbing gases in the atmosphere re-emitting long wavelength infra-red radiation absorbed from the ground. This radiation is said to be half emitted into space and half emitted toward the ground. This happens over and over, they say, creating a geometric power series of 0.5 + 0.25 + 0.125 + 0.0625 + ..... or terms of one-half raised to the nth power. This infinite series equals one, though the greenhouse warming advocates say it equals two! The half of the radiation emitted into space is 169 W/m^2 in the Kiehl - Trenberth diagram, but the half returned to the Earth's surface is twice (1.97 times to be precise) that amount. This huge exaggeration of the back radiation is a complete violation of physics. This exaggeration then causes the effects of greenhouse gases to be greatly exaggerated. In reality, a cooler atmosphere cannot emit sufficient IR toward a warmer surface to raise the temperature of the warmer surface. The power incident upon the surface minus the cooling claimed for thermals (air convection) and by evaporation of water is only 64 W/m^2, which creates a surface with a black body temperature of 183.3K or -89.8C if the surface were a black body radiator as claimed. In reality, the surface temperature with an emissivity of 0.7 is 200.4K or -72.7C. The claim is that a surface that should be at this cold temperature somehow raises its temperature to 289.1K or 16.0C by radiating much more energy than it should and most of that energy is returned to the surface thanks to a multiplier effect in the atmosphere. This violates cause and effect, not to mention basic thermodynamics in which heat energy always flows from a higher temperature body to a lower temperature body.
Note also that the Kiehl - Trenberth diagram claims that only 40/396 = 0.101 of the surface radiation passes through the atmosphere without absorption. The data on the right side of the upper part of this figure makes it clear that much more than 10% of the radiation is emitted into space from the surface despite the infra-red gases called greenhouse gases. The estimate is that it is 15 to 30% transmission.
4) The CO2 warming models believe that increased CO2 and water vapor do little to decrease the incoming solar radiation of ultraviolet, visible, and short wavelength infra-red radiations. This offsetting effect, important during the day, is underestimated, however. The greenhouse gas models do not predict the observed small decrease in the range of high day to low night temperatures as a result. The radiation absorption of CO2 and water are shown in the figure above. The three strongest absorptions of CO2 all occur where there is complete saturation of the effect due to the combination of the effects of water and already existing CO2 already. The fourth strongest absorption line lies in the longer wavelength tail of the incoming solar radiation however and the absorption frequency at which it lies is not already saturated. So although this line is weak, it actually has a significant effect as CO2 is further increased, at least as compared to the outgoing radiation effect. The effect on incoming radiation is to cool the surface by removing more incident solar energy from the spectrum reaching the surface.
5) The residence time of man's CO2 emissions in the atmosphere is about 5 years when introduced high in the atmosphere (as in nuclear blasts or some volcanic eruptions [not caused by man despite the claims of certain Iranian clerics, but useful for studies of CO2 atmospheric dwell times]), not the 50 to 200 years claimed in one part of the UN IPCC AR4 report of 2007, but in agreement with another part of the same report. Other studies of the low altitude introduction of CO2, where man's use of fossil fuels introduces the vast majority of it, show the half life in the atmosphere to be about 1 year.
6) The portion of the CO2 in the atmosphere due to man is estimated to be about 1.2% to maybe a couple of % based on other reasonable assumptions. The seas and plants are the dominant factors determining the atmospheric concentration of CO2. Warming seas increase the atmospheric concentration of CO2. Increased CO2 causes more plant growth which uses more CO2. Ocean animals with shells also use large amounts of CO2. Higher atmospheric concentrations of CO2 also cause land minerals to react with more CO2 and bind it up. Thus, plants and land minerals provide some negative feedback to increased atmospheric CO2. When man adds CO2 to the atmosphere, the increased partial pressure of CO2 in the atmosphere pushes the equilibrium concentration in the oceans at a given temperature upward, acting as a further negative feedback mechanism.
7) The hot spot in the warming pattern from about 8 to 12 km altitude near the equator that should be found if CO2 is acting as strongly as a greenhouse gas and enhancing the greenhouse gas effect of water vapor as is claimed by the UN IPCC AR4 report has been searched for. The hot spot in the atmosphere is not present. This is definitive proof that the UN IPCC computer models are wrong about the role of CO2. This reason alone is not only an adequate reason to reject the man-made CO2 contribution to global warming being as large as that claimed by the UN IPCC report, but it requires a scientist to reject this hypothesis. A theory cannot make so necessary a prediction and fail, and nonetheless still be claimed to be true. This would violate the fundamental scientific method.
8) The temperatures on other planets and moons in our solar system are also rising, which is consistent with measurements of the solar cycle. These other atmospheres are all warmer than predicted by the intercepted solar radiation energy. Many have hotter surfaces and atmospheres than Earth though they have little or no greenhouse gases.
9) Much of the claimed rise in land surface temperatures is due to the urban heat island effect, which has increased the reported temperatures in recent decades due to the closing down of more accurate rural weather stations around the world. Few station sites follow the rules for good siting. Urban stations should be entirely excluded when recording temperatures for global warming or cooling effects or assessing the effects of greenhouse gases such as CO2. Instead, low altitude and urban stations have been given fallaciously high weight in the ground temperature records by extrapolating data taken from such warmer stations onto areas far from them but at higher altitude or more remote locations. Stations at higher latitudes in Canada, Russia, and China have been preferentially shut down and temperatures for those critical areas have been assigned based on readings far to the south. The temperatures officially used for high altitudes in the Andes of Boliva are based on data from cities on the Pacific Ocean and hot jungles of the Amazon basin. The cool Andes Mountains lie between these areas and are much cooler. This trick has been used over and over around the world. Cooler temperatures actually measured decades ago have been replaced by interpolated values biased to higher temperatures in recent times. This exaggerates the apparent temperature increase.
10) Much raw temperature data has recently been pried loose from national temperature archives, often thanks to dogged requests under Freedom of Information Acts. The rural stations in the U.S., Russia, Northern Europe, northern Australia, New Zealand, China, and some areas of Canada, Latin America, and Africa whose data has been examined carefully show little to no late 20th Century temperature increase. The data used in the UN IPCC AR4 report of 2007 was heavily manipulated, in ways that make no scientific sense, to enhance a rapid rise of temperatures in the late 20th Century.
11) There is much evidence that the Medieval Warm Period, the Roman Warming, the Minoan Warming, and the Halocene Warmings b and a and other warmings longer ago were warmer than the present time, yet humans, animals, and plants thrived.
12) The rate of the temperature increase at the start of the Medieval Warm Period was similar to that we had in the late 20th Century using even the inflated and manipulated ground temperature data. There was also a warming period around 1700 in which the temperature rose 2.2C in just 36 years, compared to the 0.7C temperature increase claimed for the 20th Century. The claims of an unprecedented rise in temperatures in the late 20th Century are without justification.
13) The sea surface temperature data, the balloon data, and the satellite temperature data for the late 20th Century show much smaller temperature increases than does the manipulated land surface data used by the alarmists. The oceans and water cover 71% of the Earth and the satellites read temperatures over the entire Earth. The oceans store about 22 times the heat stored in the atmosphere. The ocean temperatures of the last 6 years are unchanged or decreasing. A better way to search for warming is to examine the heat content of the oceans using the results of the reliable Argo buoy arrays which can measure the heat content to a depth of 700 meters in the oceans. These measurements show no increase from 2003 through 2008. The entire heat capacity of the atmosphere is the equivalent of only the top 3.2 m depth of the oceans.
14) The atmospheric concentrations of CO2 follow temperature increases rather than preceding them, consistent with dissolved CO2 being emitted upon the warming of the oceans or dissolved when the oceans cool. The solubility of CO2 increases greatly with lower temperature and higher pressure. Due to high pressure and cold temperatures, the deep ocean waters hold huge amounts of CO2, but it takes a long time to warm those waters in response to solar irradiance changes due to the huge amount of heat energy needed to raise the temperature of water, the low amount of heat energy in the gaseous atmosphere, the huge volume of water, and the depth of most of the oceans. Consequently, the rise in CO2 concentrations in the atmosphere will lag general warming events by long times, though there is observable response to warming El Nino events and cooling La Nina events.
15) Despite a continued CO2 concentration increase in the atmosphere since 1998, the temperatures have not risen, which was noted as an embarrassment in the dumped CRU e-mails by Trenberth. The much-touted computer models are baffled by this.
16) Solar wind and solar electromagnetic fields are believed to have major effects upon the cosmic ray flux on the Earth and other planets in the solar system. When solar sunspot activity increases, solar irradiance increases, but so also does the solar wind and the range and strength of the solar electromagnetic field. This shields the Earth from cosmic rays and the reduced flux of cosmic rays causes less lower atmosphere (below 3.2 km) nucleation and growth of clouds. The Earth's temperature decreases sensitively to the amount of cloud cover in the lower atmosphere, so when the sun is less active, there are more cosmic rays and they generate more lower atmosphere clouds, which has a strong cooling effect. Contrary to the frequent claims of the global warming alarmists, solar activity has stronger effects upon the Earth's temperature than just that caused by the changes in solar irradiance. Both the solar and Earth electromagnetic fields are presently weaker than they have been in many decades, so cosmic radiation is not being as well shielded as has long been usual. With both fields weakened, the flow of molten material in the center of the Earth is decreased, which also should decrease the heat flow from the center of the Earth to its surface.
17) The predicted catastrophic changes due to warming do not seem to have materialized. The failure here is widespread and should not be a surprise given that these calamities did not happen during the earlier warm periods such as the Medieval Warm Period given in 11) above. The historical record indicates that man generally benefited from these warmer periods. We also know that mortality rates generally are higher due to cold weather than due to warm weather, so moderately rising temperatures are less harmful than an equivalent drop in temperatures.
So, what is the essential physics of our climate?
1) About 70% of the incoming solar radiation is incident and absorbed by the Earth's surface. Thus, (0.7)(341 W/m^2) = 238.7 W/m^2 warms the surface. With an emissivity of 0.7, the temperature of the Earth's surface is 278.5K, or only about 9.5K cooler than the average temperature we observe.
2) Most of the remaining energy is due to the action of gravity on our atmosphere and the movement of convection currents to keep the atmosphere in equilibrium. The gravity effect operates due to the energy of the ideal gas molecule being the sum of its kinetic energy and its potential energy. The higher altitude gas molecules have more potential energy and less kinetic energy and the decrease in kinetic energy is almost linear with increasing altitude. The temperature of the ideal gas in equilibrium is proportional to its kinetic energy. At sea level, the nitrogen, oxygen, and argon molecules that make up about 99.967% of the atmosphere and the remaining gas molecules are colliding about 6.9 billion times per second, so they rapidly absorb their share of energy even from the infra-red absorbing gases commonly called greenhouse gases.
3) At lower altitudes, the transfer of energy by water molecules and their phase transitions from liquid or solid state to gas and then at somewhat higher altitudes where it is cooler, back to the liquid or solid state. These transitions involve a large absorption of energy or cooling upon the transition to gas and a large emission of energy upon returning to the liquid state. Water provides a great balancing effect to the climate and very effectively counteracts either great temperature increases or decreases.
4) The average daily surface temperature is raised by the storage of large amounts of energy in water and the subsurface ground during the bright sunlight hours of the day and the return of that heat to the surface by conduction during the night. Such an effect is observed for the moon as shown below, despite the fact that the moon stores much less energy than our Earth with water covering 71% of its surface and our vegetation holding heat better into the night. The image below shows that effect NASA long ago calculated for the moon. The outer surface of the blue areas is the temperature due to the solar radiation incident with no subsurface to store heat or to be warmed by conduction. The outer surface of the orange is the observed temperature due to the subsurface heat holding effects. Note that the daily high temperature shifts to later in the day, just as on Earth, from the noontime. Note also the cooling effect during the day and the bigger warming effect at night. These effects would be more subtle on Earth due to the smaller temperature extremes, but they will still exist. In fact for a much more realistic understanding of the Earth's climate, one needs to develop the complete day to night cycle in this fashion for the more complicated Earth with its atmosphere, oceans, and plant coverage.
5) At about 4000 meters, as much energy is transferred in the atmosphere by radiation as by air molecule collisions and convection currents. The temperature of the Earth as viewed from space is about 255K, which is the temperature of the U.S. Standard Atmosphere at an altitude of 5000 meters. The atmosphere at about 5000 meters is in effective thermal equilibrium with space.
6) As one moves to lower altitudes from 5000 meters, the increasing kinetic energy of the gases as the potential energy decreases causes the temperature of the atmosphere to increase approximately linearly.
7) Energy input from the solar wind, the interaction of the solar magnetic field with that of the Earth, the conduction of heat from the Earth's hot interior including large numbers of thermal vents in the deep oceans, and debris and particles collected from space provide additional energy inputs to the Earth. It is not difficult to account for the 9.5K higher temperature of the Earth's surface compared to that expected for the average incidence of solar radiation upon its surface. What is far more interesting are the explanations as to why the Earth's surface does not rise to a temperature of 393.8K or 120.7C at noon on the average day and then fall to 3K at night with no incident sunlight.
The case for the catastrophic anthropogenic global warming hypothesis is so poor, that it is clear that the real reason so many support this false hypothesis does not lie in the science. There are ulterior political and unethical business motives for the constant claims that man's use of fossil fuels is going to be responsible for a global climate catastrophe. Those who want reasons to increase the control of our use of energy, flock to this false theory. Those who want to add further high taxes love the idea of something like cap and trade taxes. Those who wish to subject the United States to more international control, say the United Nations, love this false theory. Those who stand to make money from the trade of carbon credits love it. Those who are pushing federal investment and mandates to create the smart grid love it. Those who are working on electric cars, wind generation of electricity, solar power generation of electricity, nuclear power, thermal insulation, higher efficiency light sources, light materials for transportation, products made from recycled materials, and many others who stand to make money from throttling fossil fuel use very often support this false alarmist idea.
Disclaimer: My laboratory works on projects for oil companies, solar power companies, wind generator companies, nuclear power plants, suppliers to the coal industry, low-weight materials for transportation companies, efficient light sources, improved thermal insulation materials, materials made from recycled materials, and energy from recycled materials. My laboratory will prosper better with a strong private sector, a strongly growing economy, a limited government, and with widespread respect for science and what it can do for us to make our lives better. Bad science and the disrespect for science that it will generate is bad for the future of my laboratory.