Q WAVELENGTH DEBATE
W
IMarEST response to original argument: Where we are now
hat we need in the discussion about global warming is a careful and dispassionate evaluation of the scientific facts,
not passion, nor hysteria. The climate is always changing. What we need to know is why does it change the way it does at any one time? That we do know. For example, the climate
did indeed oscillate between extremes during the Ice Age of the past 2.6 million years, but that was because the Earth’s orbit oscillated with clockwork regularity in such a way as to increase or decrease the amount of energy Earth got from the sun. Astronomers can calculate these patterns backwards and forwards in time. Their calculations indicate that the Earth should have been cooling over the past 10,000 years, and that it will stay cool for at least the next 1,000. Clearly the warming since 1900 bucks that well-defined trend. Further careful examina- tion of the radioisotopes Beryllium-10 and Carbon-14, produced in the upper atmosphere by the impact of cosmic rays, shows that there were times during the past 10,000 years when the Earth received more than its usual share of cosmic rays and times when it received less. The number of cosmic rays impacting our atmosphere is governed by the solar wind. A strong solar wind, associated with numerous sunspots, diminishes the impact of cosmic rays, while a weak solar wind (fewer sunspots) increases it. The isotopic data thus allow us to show that
periodic changes in the sun itself (represented by cosmic ray impacts) caused slight warming or cooling above or below the overall cooling trend typical of the past 10,000 years that was driven by changes in the Earth’s orbit. One such change was the Medieval Warm Period. Are we now in a period of strong sunspot activity of the kind that might have driven temperatures to the same level as in the Medieval Warm Period? No – sunspots have been in decline since 1990.
The orbital changes of the past 10,000 years cooled the Earth into the Little Ice Age of 1350-1850. The astronomical data show we should still be in the Little Ice Age (the opposite of the supposed consensus that it had ended), for at least another 1,000 years. Did solar activity drive us out of the Little Ice Age? Or was it something else? While some of the warming since 1850 was likely due to an increase in sunspot activity after 1900, the main additional change we see is in humani- ty’s output of greenhouse gases, including CO2
, kicked off by the industrial revolution. It
has been known since the 1850s that CO2 absorbs and re-emits infrared radiation. Since
sunspot activity has decreased since 1990
while CO2 output has risen substantially, there
is good reason to suppose that it is the CO2 (and allied human emissions of greenhouse
gases) that is the main cause of the recent warming, rather than the sun’s (decreasing) output. Volcanoes are a minor part of the picture, with big eruptions causing occasional temporary cooling.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76