It is true that most Americans no longer believe in Anthroprogenic (Man-made) Global Warming. Why? Mostly because of the harsh winter that we just endured and the unusually cool spring we are looking at right now. If greenhouse gas emissions are supposed to make temperatures go up, then why are temperatures going down? That is what people are asking.
But these observations may be showing us just the beginning of things to come. Most legitimate scientists (i.e. those scientists who are not on someone's political payroll) are coming to the conclusion that climate change, whether it be warming or cooling, is driven by our sun. NASA has recently lent it's support to that position by acknowledging the possibility of a "deep solar minimum."
What that means is that our sun has slipped into a period of decreased activity and decreased solar energy output.
From Science@NASA:
| The sunspot cycle is behaving a little like the stock market. Just when you think it has hit bottom, it goes even lower. 2008 was a bear. There were no sunspots observed on 266 of the year's 366 days (73%). To find a year with more blank suns, you have to go all the way back to 1913, which had 311 spotless days: plot. Prompted by these numbers, some observers suggested that the solar cycle had hit bottom in 2008. Maybe not. Sunspot counts for 2009 have dropped even lower. As of March 31st, there were no sunspots on 78 of the year's 90 days (87%). It adds up to one inescapable conclusion: "We're experiencing a very deep solar minimum," says solar physicist Dean Pesnell of the Goddard Space Flight Center. "This is the quietest sun we've seen in almost a century," agrees sunspot expert David Hathaway of the Marshall Space Flight Center. |
And to show what that means graphically:
Sunspot counts are clearly at a minimum and that means decreased solar energy output as evidenced by the solar irradiance measurement:
NASA scientists admit that they do not know what will happen next. But it is clear that the sunspot cycle and the solar irradience cycle are more closely tied to global temperature change than any greenhouse gas emissions are. We know this because thanks to the efforts of China and India, greenhouse gas emissions have increased over the years, but global temperature has gone down, not up.
Other effects:
| A 50-year low in solar wind pressure: Measurements by the Ulysses spacecraft reveal a 20% drop in solar wind pressure since the mid-1990s—the lowest point since such measurements began in the 1960s. The solar wind helps keep galactic cosmic rays out of the inner solar system. With the solar wind flagging, more cosmic rays are permitted to enter, resulting in increased health hazards for astronauts. Weaker solar wind also means fewer geomagnetic storms and auroras on Earth. A 12-year low in solar "irradiance": Careful measurements by several NASA spacecraft show that the sun's brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996. The changes so far are not enough to reverse the course of global warming, but there are some other significant side-effects: Earth's upper atmosphere is heated less by the sun and it is therefore less "puffed up." Satellites in low Earth orbit experience less atmospheric drag, extending their operational lifetimes. Unfortunately, space junk also remains longer in Earth orbit, increasing hazards to spacecraft and satellites. |
Also, if those sunspots don't return and solar energy output does not increase, we will be in for some very cold times ahead.
You can access the complete article on-line here:
Deep Solar Minimum
Dr. Tony Phillips
Science@NASA
April 1, 2009
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