Carbon dioxide is not the major influence on climate
The government’s intention to introduce an emissions trading system in Australia rests upon their belief that human carbon-dioxide emissions are a cause of dangerous global warming. That belief is incorrect. Though carbon dioxide is indeed a minor greenhouse gas, the major control on earth’s climate has always been, and remains, the Sun.
The correlation between solar activity and climate was first noticed in ancient Greece in 400 BC (Hoyt and Schatten, 1997). The Sun’s solar cycles are normally 11 years long, and can vary from nine years to 16 years. There is a correlation between solar cycle length and amplitude, with the shorter the cycle the higher the amplitude. High amplitude cycles produce a stronger solar wind, changing the level of galactic cosmic rays impinging on the Earth’s atmosphere. This is measured as neutron counts at several stations around the planet. That in turn alters the Earth’s albedo by changing cloud formation, as increased galactic cosmic rays enhance cloud formation.
Variation in the Earth’s albedo due to changing cloud cover is sufficient to have caused the warming of the 20th century (Svensmark and Friis-Christensen, 1997). This is borne out by the relationship between Be10 levels in the Dye 3 ice core from Greenland and major climatic periods. Be10 is formed by cosmic ray spallation of oxygen and nitrogen. Spikes in Be10 levels in the Dye 3 core are associated with all the major cold periods of the Little Ice Age, including the un-named cold period at the end of the 19th century.
Friis-Christensen and Lassen (1991) found a correlation between solar cycle length and the Earth’s temperature over the following cycle. That relationship was confirmed for Armagh, Northern Ireland data by Butler and Johnson (1996) and for De Bilt, Netherlands data by Archibald (2006). A strong correlation of 0.7° per year of solar cycle length is also found in North American data (Archibald, 2009). Near term climate can be predicted from solar cycle length.
We are currently near the end of Solar Cycle 23, which became 13 years old in May 2009. At 13 years, it is 3.4 years longer than Solar Cycle 22. The demonstrated relationship between solar cycle length and temperature for the mid-latitudes of the North American continent will result in a temperature that averages at least 2.2°C colder over Solar Cycle 24 than what it was over Solar Cycle 23.
This will have the effect of shifting climatic zones 300 km towards the equator and reducing agricultural productivity. If Solar Cycles 24 and 25 both have low amplitudes, a climatic period similar to the Dalton Minimum would ensue. The Dalton Minimum, from 1798 to 1822, was a period of cool climate caused by the low amplitudes of Solar Cycles 5 and 6.
At the time of writing of this paper, the current progression of the Solar Cycle 23/24 transition points to Solar Cycle 24 having a low amplitude. Geomagnetic indices at solar minimum can be used to predict the maximum amplitude of the following solar cycle. The Ap Index suggests that Solar Cycle 24 will have an amplitude of less than 40.
NASA’s chief solar scientist, Dr David Hathaway, was recently quoted as saying, with respect to the coming two solar cycles, that, “something like the Dalton Minimum — two solar cycles in the early 1800s that peaked at about an average of 50 sunspots — lies in the realm of the possible.”
Ocean heat content and atmospheric temperature both started declining after the peak in solar proton flare and geomagnetic activity in 2003. This established cooling trend is expected to accelerate. The current cooling has already has an effect on agricultural production, with the 2009 Canadian wheat crop down 20% due to a cold spring.
Introduction of an Australian emissions trading scheme based upon a presumption of dangerous global warming just as Earth enters a likely twenty year period of cooling is a misguided, and potentially disastrous, climate policy choice to make.
Archibald, D, 2006. Solar Cycles 24 and 25 and predicted climate response, Energy and Environment, 17:29-38.
Archibald, D, 2007. Climate outlook to 2030, Energy and Environment, 18:615-619.
Archibald, D, 2009. Solar cycle 24: Expectation and implications. Energy and Environment, 20:1-11.
Butler, C J and Johnston, D J, 1996. A provisional long mean air temperature series for Armagh Observatory, Journal of Atmospheric Terrestrial Physics, 58:1657-1672.
Friis-Christensen, E and Lassen, K, 1991. Length of the solar cycle: An indicator of solar activity closely associated with climate, Science, 254:698-700.
Hoyt, D.V and Schatten, K.H. The Role of the Sun in Climate Change Oxford University Press, 279 pages.
Loehle, C, 2009 Cooling of the Global Ocean Since 2003. Energy and Environment, 20:101-104.
Spencer, R W, Braswell, W D, Christy, J R and Hnilo, J, 2007. Cloud and radiation budget changes associated with tropical intraseasonal oscillations, Geophysical Research Letters, 34, L15707, doi:10.1029/2007GL029698.
Svensmark, H and Friis-Christensen, E, 1997. Variation of cosmic ray flux and global cloud coverage – A missing link in solar-climate relationships, Journal of Atmospheric and Solar-Terrestrial Physics, 59(11):1225-1232.
David Archibald is a Perth-based scientist operating in the fields of climate, cancer and oil exploration.