maxmaximus Posted March 21, 2013 Share Posted March 21, 2013 You said earlier that the volcanoes also destroyed the plant life..as a general question would you prefer a cooler earth or a warmer one? (it won't stay the same as now because the climate has never been stable) They did in the earth's past when the planet was more volatile, and an eruption from Yellowstone's supervolcano could create an ash cloud that would affect the entire world's atmosphere for a decade or more. Link to comment Share on other sites More sharing options...
truman Posted March 21, 2013 Share Posted March 21, 2013 They did in the earth's past when the planet was more volatile, and an eruption from Yellowstone's supervolcano could create an ash cloud that would affect the entire world's atmosphere for a decade or more. So do you want a warmer earth or a cooler one? Link to comment Share on other sites More sharing options...
Jeffrey Shaw Posted March 21, 2013 Share Posted March 21, 2013 Never mind the far past of which you claim knowledge. There have been several such eruptions within the last two centuries, one of which led to a 'Year without a summer' (1816). See http://history1800s.about.com/od/crimesanddisasters/a/The-Year-Without-A-Summer.htm Link to comment Share on other sites More sharing options...
Obelix Posted March 21, 2013 Share Posted March 21, 2013 In the late Ordovician period CO2 was at about 10-15 times the level of today..yet there was an ice age.... The average Ordovician temperature was 2C more than the current levels, but considering most of the continental crust was clustered around the south pole I'm not surprised there was still extensive glaciation.... Link to comment Share on other sites More sharing options...
maxmaximus Posted March 21, 2013 Share Posted March 21, 2013 Never mind the far past of which you claim knowledge. There have been several such eruptions within the last two centuries, one of which led to a 'Year without a summer' (1816). See http://history1800s.about.com/od/crimesanddisasters/a/The-Year-Without-A-Summer.htm Indeed, imagin that happening now with 7 billion people to feed, 7 times more than then. The Year Without a Summer, a peculiar 19th century disaster, played out during 1816 when weather in Europe and North America took a bizarre turn that resulted in widespread crop failures and even famine. Link to comment Share on other sites More sharing options...
Obelix Posted March 21, 2013 Share Posted March 21, 2013 Errrr.go on..you'll have to explain that..why does plate tectonics affect the ability of plants to absorb CO2? I think he's asking the wrong question Truman - plate tectonics is the biggest control on CO2 there is at the moment. If the himalayan plateau wasnt as high as it is now, and not subject to the weathering it has now, the CO2 level would be many times higher. The erosion of silicate rocks by carbonic acid rain is the biggest control on CO2 we have atm, far more so than green plants the capture CO2, die rot and release it all back again.... Link to comment Share on other sites More sharing options...
truman Posted March 21, 2013 Share Posted March 21, 2013 Did CO2 level rise after the ice formed due to lack of tree and phytoplankton. If the planet was covered in plants that use CO2 then the level would drop, with less CO2 it would get colder and ice would start to form, ice reflects the suns energy so it gets colder, plants can’t grow so can’t remove CO2 so the level starts to rise, but it needs lots of CO2 to counter the effect of the ice reflecting the suns energy. This process takes millions of years so at some point one would expect there to be ice and high levels of CO2, also much of the land mass including Africa was at the south pole. The earth wasn't "covered in plants " in the Ordovician period..it was probably only located near to shorelines and were probably just mosses and the like..no large forests of trees..the CO2 concentration just before the late Ordovician glaciation was estimated at 4400ppm.. just for perspective we are at about 390ppm at the moment..so the gas you're blaming for global warming was 10 times more concentrated then..yet there was an ice age.. ---------- Post added 21-03-2013 at 15:17 ---------- The average Ordovician temperature was 2C more than the current levels, but considering most of the continental crust was clustered around the south pole I'm not surprised there was still extensive glaciation.... With CO2 levels more than 10 times what we have now I'm surprised any ice was left at all..after all aren't they saying that we are losing arctic and antarctic ice at a rate "greater then first thought" even with our low concentration. ? Link to comment Share on other sites More sharing options...
Cyclone Posted March 21, 2013 Share Posted March 21, 2013 Human CO2 emissions are far greater than volcanic emission and humans destroy the photovoltaic life forms needed to reduce CO2. We alter the feedback loop you keep talking about. The planet will cope fine despite our presence, we on the other hand won't We don't alter the feedback loop, we just feed into it. I don't think you mean photovoltaic though, plants don't generate electricity from sunlight, they generate sugar and oxygen. Link to comment Share on other sites More sharing options...
Tim Grindley Posted March 21, 2013 Share Posted March 21, 2013 Sea level rise isn't the biggest concern. Oh, right what is? It being a bit warmer and farming being more productive due to warmer weather and more CO2? And more rainfall? Like in the Bronze age. Or is it a possible slight increase in storms? Very poor mechanisim and even poorer data to support that one. What is the issue? Link to comment Share on other sites More sharing options...
maxmaximus Posted March 21, 2013 Share Posted March 21, 2013 The earth wasn't "covered in plants " in the Ordovician period..it was probably only located near to shorelines and were probably just mosses and the like..no large forests of trees..the CO2 concentration just before the late Ordovician glaciation was estimated at 4400ppm.. just for perspective we are at about 390ppm at the moment..so the gas you're blaming for global warming was 10 times more concentrated then..yet there was an ice age.. How may million years is “just before”. Plants were mainly in the oceans and eventual fossilised into oil and gas. Volcanic activity could also stop the suns energy reaching earth, it’s also been pointed out several time that the land mass was at the South Pole, was the south pole at the time tilted away from the sun? ---------- Post added 21-03-2013 at 15:32 ---------- We don't alter the feedback loop, we just feed into it. I don't think you mean photovoltaic though, plants don't generate electricity from sunlight, they generate sugar and oxygen. Correct I don't photosynthetic organisms ---------- Post added 21-03-2013 at 15:35 ---------- Oh, right what is? It being a bit warmer and farming being more productive due to warmer weather and more CO2? And more rainfall? Like in the Bronze age. Or is it a possible slight increase in storms? Very poor mechanisim and even poorer data to support that one. What is the issue? Less land for farming, plants, insects, and other life forms failing to adapt to the higher temperature. ---------- Post added 21-03-2013 at 15:37 ---------- I think he's asking the wrong question Truman - plate tectonics is the biggest control on CO2 there is at the moment. If the himalayan plateau wasnt as high as it is now, and not subject to the weathering it has now, the CO2 level would be many times higher. The erosion of silicate rocks by carbonic acid rain is the biggest control on CO2 we have atm, far more so than green plants the capture CO2, die rot and release it all back again.... Thats something I didn't know, thankyou. Link to comment Share on other sites More sharing options...
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