On 7 Feb 2007 17:52:10 GMT, William Asher <
[email protected]> wrote:
>Do you understand the significance of Figure SPM-2 in the executive
>summary? Can you explain to me how all these other very minor effects are
>going to dominate the warming forcing produced by anthropogenic CO2?
>Explain how solar irradiance for instance, which is an order of magnitude
>less than CO2 in terms of effect, could be causing the observed warming.
>What process not listed in the figure, if it is not CO2, is responsible?
I don't deny that CO2 has the effect of increasing the greenhouse
effect, or that human activity has increased atmospheric CO2.
However, we also know that the sun's activity has increased at the
same time.
Here's an article from the Telegraph.
"The truth about global warming - it's the Sun that's to blame
The Telegraph, UK
By Michael Leidig and Roya Nikkhah
Last Updated: 11:15pm BST 17/07/2004
Global warming has finally been explained: the Earth is getting hotter
because the Sun is burning more brightly than at any time during the
past 1,000 years, according to new research.
A study by Swiss and German scientists suggests that increasing
radiation from the sun is responsible for recent global climate
changes.
Dr Sami Solanki, the director of the renowned Max Planck Institute for
Solar System Research in Gottingen, Germany, who led the research,
said: "The Sun has been at its strongest over the past 60 years and
may now be affecting global temperatures.
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"The Sun is in a changed state. It is brighter than it was a few
hundred years ago and this brightening started relatively recently -
in the last 100 to 150 years."
Dr Solanki said that the brighter Sun and higher levels of "greenhouse
gases", such as carbon dioxide, both contributed to the change in the
Earth's temperature but it was impossible to say which had the greater
impact."
There have been many warming periods in the past during times when
there was no CO2 increases, so obviously the climate can warm up
without any increase in CO2.
Personally, it seems logical to assume that because CO2 is a
greenhouse gas that increased levels of CO2 will result in a
temperature rise. I have no problem with that. However, there is no
way to determine exactly how much of the current warming trend is due
to CO2. It could be responsible for most of it or it could be
responsible for a small amount. The point is that there is no way to
tell. As Dr. Solanki says it's impossible to say which had the
greater impact.
In addition, I will say that there could be other factors in addition
to CO2 and the Sun's activity at work. The earth could be getting
more cosmic radiation from outer space for all we know, or ocean
currents and continental drift could be the culprit, or any
combination of all of the above. The climate system is too complex to
be able to isolate any single factor and say with certainty exactly
what contribution it is making to climate change.