From Quora
David Charles Leithauser
Consultant (1980-present)5y
Historical data shows that CO2 levels lag temperature. What reasoning
supports increasing CO2 levels as the cause of global warming versus an
effect?
The idea that CO2 lags temperature is oversimplified. Increased
temperature can cause increased CO2 for several reasons. The main one
is that warmer water cannot hold as much CO2, so when the temperature
goes up the oceans releases CO2. Also, soil releases CO2 when it gets
hot, not to mention the fact that increased heat causes forest fires.
However, increased CO2 also increases the temperature by trapping the
sun's heat. Thus, you have a vicious cycle. Increased CO2 increases
temperature which increases CO2 which increases temperature, and so on,
until the cycle stops when almost all of the stored CO2 has been
released.
This cycle can be started either way, with warming first or release of
CO2 first. When a natural event, like a slight change in the Earth's
tilt, causes a slight increase in the ocean temperature, the cycle can
start up and perpetuate itself. On the other hand, an increase in CO2,
whether from natural sources like super volcanoes or unnatural sources
like humans burning fossil fuels, can trigger the vicious cycle.
Those who like to deny human caused global warming for their own
political or economic reasons will often cherry pick the geological
record and point to periods in the past when natural warming triggered
the cycle. Looking that those period, you see the warming first and
then the increase in CO2. They then ignore the rest of the cycle,
trying to make it look like the only effect was the increased CO2 due
to the warmer temperatures. However, you can also look at periods when
release of CO2 from super volcanoes or other sources started the cycle,
like about 200,000,000 years ago when a super volcano triggered global
warming that killed off about 1/2 of all life on earth. Looking at the
present, we see human released CO2 warming the Earth. There is no
natural cause for this warming. In fact, most natural events like the
current tilt in the Earth's axis would be having a cooling effect.
Historical data shows that CO2 levels lag temperature. What reasoning supports increasing CO2 levels as the cause of global warming versus an effect?
Bruce Jones
MBA, Statistician, Six Sigma Black Belt, Modeling Climate Change Data Since 2006
The "reasoning" is based on evidence, today's carbon cycle is very different from the natural pre-industrial cycles.
In fact, the three primary greenhouse gases are off the charts:
And temperatures are following:
Scott Strough
·
Follow
Researcher in carbon farming as a climate change mitigation strategy5y
Very simple. Historically CO2 was most of the time a reinforcing feedback. That means it took a tiny warming from some other forcing like a solar cycle and reinforced the effect making it warmer still. Our current situation is a bit different. We are first warming the planet by increasing the CO2, and still must wait for the natural reinforcing feedbacks to kick it warmer still. Be prepared. It is coming. Once the lagging natural reinforcing feedbacks catch up to our own CO2 emissions, we have every reason to believe it will accelerate too.
Your question is often misused by climate deniers to hoax people into believing AGW is not real, when actually this very fact is what makes AGW likely very dangerous.