GW Its definitely not caused by man at all its all natural its the planets cooling and warming cycle that has been going on for millenniums.
The irony of this statement is that
the reason we have a good idea that humanity is likely causing the bulk of the current global climate change is because of the analyses based on the geologic history of the earth!
The claims that since the earth has had different climates in the past ergo it couldn't be humanity is a logic fallacy.
1. Gunshots to the head often lead to death.
2. Bob is dead.
3. Ergo Bob was shot in the head.
Not necessarily so, obviously.
The amount of stuff we know about
why the earth's climate changes helps us understand the drivers, the
forcings which affect the climate. And we know that the usual "natural forcings" that have affected the climate in the past appear to pail in comparison to what humanity is currently doing.
1. We know that CO2 is a greenhouse gas. Due to the nature of its chemcial bonds it absorbs in the IR region. We've known this since the middle 1800's.
2. We know we are pumping billions of tons of
excess carbon into the atmosphere at a rate many, many many times faster than the carbon was initially sequestered from natural cycles. Much of this carbon hasn't been in the natural carbon cycles for millions of years
3. Starting in the middle-19th century, about the time we started pumping masses of fossil and vegetal fuels into the air during rapid industrialization, the
isotopic signature of the atmospheric C in CO2 started to shift to lighter stable carbon isotopes just as you would predict from the dumping of huge amounts of fossil fuels and vegetal fuels derived carbon into the atmosphere from it's combustion.
Right now there are almost no professional climatologists who
don't believe that human-induced climate change is real. By a couple different estimates about 97% of professionals in this field feel it is real.
That's pretty amazing when you think about it. The science is pretty solid and the fact that more than 90% of the worlds professionals in a field
actually seem to agree (not an easy task to get scientists to agree unless the science is pretty solid) would seem to say a LOT.
And the science "makes sense", passes the "sniff test" to non-climatologists like myself. I'm an earth scientist by training and degree but I'm not a climatologist. The science makes sense and seems reasonable to me.
I see no reason to make such strong statements as yoursm Greatcloud. If you wish to hold the opinion you hold of the science, you should be careful to note that use of words like "definitely" don't necessarily apply since you are aligned with only about 3% of the professionals in the associated fields.
Going up against 97% of the scientists would not seem to be the safest of bets in this day. (and note: this isn't the 1600's so bringing up folks like Gallileo won't work either because in this case the world's scientists have been doing
real science, not just taking accepted wisdom. They've been studying this.)