reply to post by SimonPeter
So then why can't 'natural' process account for the extreme jump in warming in the past 30 years? To our knowledge this is the fastest heating that
has ever occurred in the past 650,000 years. If you can find me any proof that this heating occurred at another time in the exact span of years you
may have something.
For instance I can find proof of what I'm talking about, such as, from NATGEO: Glaciers are melting, sea levels are rising, cloud forests are drying,
and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping
gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.
In reference the last ICE AGE, which is what you say causes this, only happened 110,000-10,000 years ago. So how's that make green houses now the
highest in 650,000 years? According to you if your model was correct it would be at the same levels of 110,000 years ago but it isn't.
Or how about this: The average global temperature and concentrations of carbon dioxide (one of the major greenhouse gases) have fluctuated on a cycle
of hundreds of thousands of years as the Earth's position relative to the sun has varied. As a result, ice ages have come and gone.
However, for thousands of years now, emissions of GHGs to the atmosphere have been balanced out by GHGs that are naturally absorbed. As a result, GHG
concentrations and temperature have been fairly stable. This stability has allowed human civilization to develop within a consistent climate.
Occasionally, other factors briefly influence global temperatures. Volcanic eruptions, for example, emit particles that temporarily cool the Earth's
surface. But these have no lasting effect beyond a few years. Other cycles, such as El Niño, also work on fairly short and predictable cycles.
Now, humans have increased the amount of carbon dioxide in the atmosphere by more than a third since the industrial revolution. Changes this large
have historically taken thousands of years, but are now happening over the course of decades.
So get to doing some homework and find me any period, in a 30 year span, where the climate has jumped at such an alarming rate. There isn't and anyone
who thinks humans have nothing to do with this is incredibly dim-witted.
Nasa has plenty of evidence: climate.nasa.gov...
edit on 1-12-2012 by NoJoker13 because: (no reason
edit on 1-12-2012 by NoJoker13 because: (no reason given)