A previous post on SLB (see link) gave seven causes (non-CO2) of measured atmospheric measured warming, especially near the surface where land temperature measuring systems are located. In the US, there are thousands of such sites known as the USHCN, US Historical Climate Network, and a more recent hundred sites known as the USCRN, US Climate Reference Network. As argued before on SLB, it is entirely wrong for climate scientists to measure one effect, increase in temperature over time, and attribute that to increased CO2 in the atmosphere when there are so very many other known causes of increased temperature trend.
The previous post's seven known causes will be added to in this article, bringing the total to ten. Those seven are:
1. Increased population density in cities (more buildings in a small area)
2. Increased energy use per capita (each building uses more energy, and people use more)
3. Increased local humidity due to activities such as lawn watering, industry cooling towers
4. Prolonged drought (the opposite, regular rain, reduces temperatures in arid regions)
5. Reduced artificial aerosols via pollution laws being enforced
6. Change in character of the measurement site, from rural to more urban with pavement and other artificial heating
7. Wind shadows from dense buildings prevent cooling winds from reaching thermometer
Causes 8, 9, and 10 are:
8. El Niño short-term heating effect in many areas (e.g. the US South and Southeast)
9. Reduced sunspot activity and number that allows more cloud-forming cosmic rays to reach Earth
10. Fewer large volcanoes erupting with natural aerosols flung high into the atmosphere
Short-term El Niño Effect
The El Niño-Southern Oscillation, ENSO but more commonly just El Niño, is a complex, repetitive natural phenomenon in which the Pacific Ocean surface changes every few years from a warm to a cool state. NOAA has long discussions on the El Niño and its opposite, La Niña. For atmospheric temperature measurements, El Niño typically, but not always, brings more rain and snow to the Pacific states, and hotter temperatures with less rain to the South and Southeast states. The usual mechanism is a southerly shift in the jet stream, so that Pacific storms are brought across California, but turn to the north in mid-continent. The temperature trends in many climate-related publications show the temporary warming of an El Niño, with a characteristic rise around 1983, 1998 and again in 2015.
Reduced Sunspot Activity
It is known that reduced sunspot activity, measured by visible sunspots, is associated with reduced solar magnetic field strength. The smaller solar magnetic field deflects fewer galactic cosmic rays, allowing more such GCRs to reach Earth. The GCRs are known to create cloud nuclei in the atmosphere that leads to more cloud formation and less sunlight reaching Earth. The opposite is also true: sunspot cycles with greater sunspots result in fewer clouds and more sunlight warming the Earth.
Fewer Large Volcanoes Erupting
This one is related to the aerosols discussed in Point 5 above, artificial aerosols. However, volcanic eruptions can send huge clouds of dust and sulfur compounds high into the atmosphere so that sunlight is affected for weeks and months. Less sunlight reaches the Earth surface.
Roger E. Sowell, Esq.
copyright (c) 2017 by Roger Sowell - all rights reserved
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