[emily2otters]

today it occurred to me to wonder: is the global temperature expected to rise indefinitely if we continue with our fuelish ways, or will it eventually reach a peak/plateau?

[brianthepoet]

if you ask me (i guess you did) the authorities are, as they have with water shortage scares, trying to take us fluoride. The answer lies in radiation - that is, just as the sun dissipates heat into space by radiation, so does and moreso will the earth as it overheats.
It's frightening to think that with 5000 kg of plutonium dust in the atmosphere(1975) and spreading to our lungs and organs that soon it may not be possible to kiss anyone without contracting some form of leukemia - on the bright side, fossil fuel usage will decline as we all start to glow in the dark!



Thank God there is only one infinity! (brianthepoet)

[nemo]

my limited understanding of the earth's climate is that it follows a cycle of warming and cooling. your question; however, raises one of my own:
with all the emphasis being placed on cleaner burning fuels and alternative methods of meeting our economy's energy needs, is there any way to actively reduce the pollution already in our atmosphere? perhaps something like a large, solar powered Ionic Breeze (http://www.sharperimage.com), or are we stuck with planting as many trees as possible?

[Little Bang]

If you look at the graph of the change in global temperature over the past 400,000 years and compare it to the CO2 concentrations over the same 400,000 years, they almost look like duplicates.
Meaning the temperature raises and falls in direct proportion to the CO2 levels in the atmosphere. The CO2 levels over the past 400,000 years has been between 200 and 300 parts per million. It was at 370 ppm in 2000. In the past 20 years the global temperature has climbed by 4/10 of a degree C.
A continued raise of between 4 and 5 degrees c. will boil off the approximately 40 billion tons of carbon locked up as methane ice on the ocean floor. that will raise the temp, another 5 degrees c. and that my dear friends will wipe out nearly 95% of all life.

[UncleAl]

For whatever reason the Earth alternates between a warm and wet Eden (e.g., the Carboniferous period) and frozen solid (ice ages). We are ramping up through an interglacial period. It will be warm and wet. Nothing is out of the ordinary. The Atlantic Ocean averages two miles deep, the Pacific Ocean three. What is a foot or two, give or take, compared with 11,000 feet average depth?

Venus is closer to the sun than the Earth. Calculate its insolation, power/m^2, compared to that of the Earth. Any runaway Greenhouse Effect on Earth will then be proportionately less severe than that of Venus.

[Little Bang]

It’s very difficult to find data that supports rhetoric. There is data for anyone to see that supports my statements.

http://www.geocraft.com/WVFossils/last_400k_yrs.html
http://www.cru.uea.ac.uk/cru/info/warming/
http://www.oism.org/pproject/s33p36.htm

[Gabriella]

Little Bang, I have to admit I like Uncle Al's explanation better. Gives me that warm
Santa was here feeling.

[Little Bang]

I will agree Gabriela, I would prefer that the status quo be maintained. However there is a precedent in history for what I say, the mass extinction around two hundred million years ago is suspected of haveing been caused by a drastic build up of co2 in the atmosphere. That one wiped out 97% of all life on the Earth.

[Shapedoctor]

Originally Posted by UncleAl

For whatever reason the Earth alternates between a warm and wet Eden (e.g., the Carboniferous period) and frozen solid (ice ages). We are ramping up through an interglacial period. It will be warm and wet. Nothing is out of the ordinary. The Atlantic Ocean averages two miles deep, the Pacific Ocean three. What is a foot or two, give or take, compared with 11,000 feet average depth?

Venus is closer to the sun than the Earth. Calculate its insolation, power/m^2, compared to that of the Earth. Any runaway Greenhouse Effect on Earth will then be proportionately less severe than that of Venus.

Nice rose colored glasses you're wearing. Where'd you get them?

[justforfun]

okay, the little bang guy's got a point. But my question is how did we go from runaway greenhouse heating to an ice age in the past, and how do we know that greenhouse warming is the only thing keeping us from going into an ice age now? We need more data, especially on how 'global warming' affects local weather. Stay tuned ...