Preface:Please read the endnotes before forming a conclusion on my views on global warming.
National Geographic reported in 2006 that the Earth’s magnetic field is changing rapidly. However, according to the article, decreases in the strength of the magnetic field do not directly affect surface temperatures:
The decline in the magnetic field also is opening Earth’s upper atmosphere to intense charged particle radiation, scientists say….
“It is in this region that the shielding effect of the magnetic field is severely reduced, thus allowing high energy particles of the hard radiation belt to penetrate deep into the upper atmosphere to altitudes below a hundred kilometers (62 miles),” Mandea said.
This radiation does not influence temperatures on Earth. The particles, however, do affect technical and radio equipment and can damage electronic equipment on satellites and airplanes, Olsen of the Danish space center said.
In addition, two Danish geophysicists at Aarhus University in western Denmark propose that the increased cosmic radiation allowed by a weakened magnetic shield in turn changes the amount of rainfall at the tropics, thus affecting climate (they acknowledge that CO2 also affects climate, but state that climate is more complex than generally believed).
Nigel Marsh of the Danish Space Research Institute in Copenhagen also argues that clouds are scarce near the equator and thicker towards the tropics, because cosmic rays have a hard time punching through Earth’s magnetic field at the equator, but can leak in through the relatively weaker field nearer the poles. If correct, this bolsters the Danish geophysicists’ hypothesis that changes to the Earth’s magnetic shield affect cloud cover (and thus precipitation and climate in general).
Moreover, it is known that intense solar activity can destroy ozone in the Earth’s atmosphere, thus affecting climactic temperatures. See this, this, this, this and this. Indeed, the effects of solar energy on ozone may be one of the main ways in which the sun influences Earth’s climate.
The sun itself also affects the Earth more than previously understood. For example, according to the European Space Agency:
Scientists … have proven that sounds generated deep inside the Sun cause the Earth to shake and vibrate in sympathy. They have found that Earth’s magnetic field, atmosphere and terrestrial systems, all take part in this cosmic sing-along.
Indeed, the very position of the Earth and sun effect climate. Scientists know that Earth’s weather is hugely affected by factors such as, according to a well-known treatise:
(1) the shape of the ellipitical orbit (with a time scale of about 95,000 years); (2) the tilt in the earth’s axis of rotation (approximately 42,000 years); and (3) the time of year when the earth is closest to the sun, or perihilion (about 21,000 years)
The Earth periodically enters ice ages and warming periods, and scientists have attempted to work out the cycles according to the Earth’s orbit, tilt, etc. When I studied climate at a university in the early 1980′s, I was taught that the Earth is in an “ice age” most of the time, and that the warmer interglacial periods were more rare.
Scientists have recently discovered that cosmic rays from a “mysterious source” are bombarding the Earth (and see this). This is occurring at the same time that the protective bubble around the sun that helps to shield the Earth from harmful interstellar radiation is shrinking and getting weaker.
In addition, a recent study shows that increased output from the Sun might be to blame for 10 to 30 percent of the global warming that has been measured in the past 20 years. The sun is simply getting hotter. Indeed, solar output has been increasing steadily ever since scientists have been able to measure it. Another study shows that solar activity variations have a “marked influence” on the Earth’s climate.
If extra-planetary events affect Earth’s climate, wouldn’t other planets in the solar system be affected as well?
The sun also apparently affects the amount of rainfall on Earth, which in turn affects climate.
Notes: I am not arguing for “doing nothing”. I am all for reducing our reliance on oil and for developing clean energy alternatives. Oil does a lot of harmful things in addition to producing CO2. And I am strongly for alternative energy, as I believe that it decreases centralization and therefore increases democratic trends. Oil also produces a lot of plain old pollution, in the extraction, processing and burning phases.
Like the Danish geophysicists discussed above, I believe that does increase warming trends. However, like them, I think that climate modeling is complex and that the effects from other causes have not been sufficiently taken into account. Indeed, if extra-planetary and other conditions align towards warming, then I think we could experience severe warming in the future. Under some scenarios, even modest warming at the Arctic could release methane, which could lead to dramatic results.
On the other hand, if the most important factors align towards cooling trends, then even with greenhouse gasses, we could experience cooling.
And – unless we understand the science of natural extra-planetary events – we could be sitting ducks if something really big happens “out there”. I believe that the science of extra-planetary events on Earth is in its infancy. I passionately urge governments and universities to expand their research in this area.