> Does anyone know how (if?) the Solar energy output measured on Earth
> varies over time? Could it be the global warming is just a result of
> increased Sun activity and all the rest has been talk?
> BTW, I am not saying we don't have to reduce CO2 emissions - we are
> likely to need to breathe for some time to come - I just wonder if
> anyone would know these particular figures.
> Chris Hofmeyr provided some very interesting ones so far.
"Over time" is pretty relative! Currently stats on global warming are being
disputed due to the methods being used to arrive at a definitive figure of
merit. There are 500 years of surface measurements (Chinese, and the
world), 100+ years of balloon measurements, and a few years of satellite
measurements. Surface measurements are questionable over time due to subtle
natural and manmade environmental changes at the point of measurement.
Try the following article for some information (there is a lot more on the
web about disagreements on methods and results be touted concerning global
Another article is:
"In response to George Melloan's Sept. 22 Global View column concerning Al
Gore and global warming:
The earth has been warming for the past 10,000 to 15,000 years for reasons
that have nothing to do with man-made "greenhouse gasses." The cost to
reduce artificial emission of carbon dioxide could thus be a terrible waste.
Mr. Melloan correctly notes that we should look to the facts, not to
speculative computer models, to understand global climate change. The earth
is warming from the last ice age; industrial gas emission is insignificant
compared with greenhouse gasses from natural sources, and biologic and
geologic processes regulate atmospheric carbon dioxide.
The geologic record suggests Earth could stay warm for another 400,000
years, no matter what we put into the air. The latest ice age just ended
some 10,000 to 15,000 years ago. Warm periods that alternated with the ice
ages of the past two million years persisted for 100,000 to 400,000 years
each. A long warming trend unrelated to industrial gasses may have barely
Industry contributes too little carbon dioxide to affect global climate.
Industrial carbon dioxide, six billion tons annually, is a small fraction of
the 700 billion tons per year from geologic and biologic processes.
Increasing atmospheric concentration of carbon dioxide stimulates plant
life, which in turn consumes more carbon dioxide. Marine plants, such as
calcareous algae, and other reef-forming organisms can sequester vast
amounts of carbon dioxide in the calcium carbonate, or limestone, that they
produce. Extensive limestone deposits thousands of feet thick that occur
throughout the geologic record provide evidence of this process.
We accept our inability to prevent regional, transient, climatic
catastrophes such as floods, hurricanes and tornadoes, yet people whose
economic interest is vested in government grants to study greenhouse gasses
claim we can alter global climate change that spans thousands of lifetimes.
Victor H. Abadie III, Geologist, Montara, Calif. "
High Plains Drifter