By Ed Caryl
There have been multiple studies of solar influence on global and regional temperature changes. Just of few of them are here, here, here, and here. This author made a contribution to the question here. Many of these studies show a some correlation of the sun’s output versus temperature, but most researchers think that this relationship is a weak one, contributing from one third to one half of the observed warming. So, from where is the remainder coming?
Pierre and this author have written about urban warming here and here. It is clear from the infrared satellite photos by NASA that urban heat islands are both more wide spread and warmer that previously known. Particularly in the eastern half of the U. S., the heat islands are blending together, raising the temperature of the whole region. How much?
No one (to my knowledge) has researched what part of the global temperature rise is due to energy use. All energy use ultimately goes to heat. This is what causes the heat islands. Much of energy usage is immediately wasted as heat: cooling towers at power plants, automobile radiators, heat loss through home insulation, heat loss up the chimney, electric motor heat loss, heat from electric lights, are just a few examples of heat losses. Even energy used to transport things is ultimately lost as heat. Just moving something through the air, heats the air. For this reason, we can convert all the energy used into watts and calculate the temperature rise. In these calculations, the energy used will be considered over particular land areas.
The first area considered is the U.S.A. There are figures for the energy consumption in the U. S. in 2005, 29 Pwh (Petawatt hours, a PetaWatt is 1015 watts. That is 1 with 15 zeros. The area of the contiguous U. S. (the lower 48 states) is 8,080,464 km2. If we divide the energy used by the area, we get 3,589 Wh/m2. Divide that by 8766 hours in a year we get 0.409 W/m2, or 9.826 Wh/m2/day, as the average energy dumped into the environment in the U. S. in 2005.
The sun provides about 4.5 kW/m2/day on a horizontal, flat, black, surface at the average latitude of the U.S. The average albedo of the earth’s surface is 0.3, which means that on average, the surface will absorb 70% of the insolation (solar energy) that strikes it. This means that the effective heating will be 70% of 4.5 kW/m2/day, or 3,150 W/m2/day. The energy dumped into the environment by every American’s energy use is 0.312% of the sun’s energy. This will raise the temperature by 0.312%. The average temperature in the U. S is 11.6°C or 284.75°K. The temperature rise will be about 0.89°C.
As you can see on the temperature chart below from NOAA, this will neatly take care of the temperature rise seen in the last 25 years.
What about the global picture? Figures are available for global energy consumption for 1988 through 2006. As most of this consumption is in the northern hemisphere, and that is where we see the most warming, the calculation uses the northern hemisphere land area, 100,228,500 km2. The same average insolation value will be used as in the U. S. example above, 3150 W/m2/day. Figure 3 is a chart of global and hemispheric temperature trends and the calculated temperature rise in the land area of the northern hemisphere due to energy usage. The temperature anomaly data comes from GISS/NASA here. The chart may underemphasize the temperature rise due to energy use because energy use is localized to a limited local areas in few countries: the US, Europe, including Russia, and China. The temperature data may also be overemphasized because the surface temperature measuring sites are at airports and other urban settings that are even warmer than the average location.
Dr. Richard C. Wilson states that 50% of the temperature anomaly is due to total solar irradiance changes (TSI). Drs. Judith Lean and David Rind make predictions based on TSI along with ocean cycles. Neither mentions any influence from energy usage.
Here are two maps. The first is the lower troposphere temperature rise over the period 1978 to 2006, much the same period as the chart above.
The second map is of energy usage by country.
Though the energy usage map is very coarse, one can see that the maximum energy usage area roughly coincides with the same areas as the northern hemisphere temperature rise.
The planet has been heating in the last two hundred years. Some of that change in temperature comes from ocean cycles, some from the sun and its various influences, and some from man. Much of the anthropogenic (man caused) portion is simply energy use that has dramatically increased in the last fifty years. A thorough, honest, investigation needs to be done before we blame it all on CO2.