> "the historical record", by which you mean *human* historical record, is
> highly overrated (nigh worthless) when you are talking about geological
> timescales, even on topics with as short a timescale as climate.
There has been a significant recent increase in global CO2 concentrations.
The vast preponderance of the new CO2 in the atmosphere is due to human
activity starting around the industrialization of Europe, and accelerating
after WWII. Most scientists studying global climate change believe that
these increased CO2 concentrations are the primary causal agent for
increased global warming. Hence our interest in items of human time scale.
> It is worth noting that underneath the receding glaciers deposited
> during the last major ice age, they are finding substantial evidence of
> humans living in what was a nice temperate climate before the glaciers
> paved over their civilization.  The receding glaciers have turned into a
> bit of an archaeological treasure chest, as they expose artifacts buried
> in and underneath them as they shrink that have been preserved by the
> ice for thousands of years.  I don't see any compelling reason to "save
> the glaciers" anyway, particularly in light of the fact that their
> existence has always been transient.
Most global climate change scientists would agree that temperatures in the
past have often been much warmer than today. The point of global warming
isn't to save the Earth -- the planet is not sentient. The point is to
understand and potentially reduce the impact of increasing temperatures on
global human activity.
> For anyone to insist that the current negligible fluctuations are
> anthropogenic just heaps one ridiculous assertion upon another.  I'll
> just stick with Occam's Razor for now.
The increase in atmospheric CO2 concentration is due to human activity.
It is generally accepted that increases in CO2 in a closed environment
subject to solar heating retain more of that solar energy. This is the
current best explanation for the high temperature of Venus. If the CO2
concentration goes up globally (which it has), then theory states the earth
should be retaining greater solar energy. This process may be slow, and may
be difficult to monitor due to the variability of temperatures worldwide. I
encourage you to refute any part of this causal chain linking CO2 to
eventual increases in global energy content, part of which will be evident
as heat.
- Jim