6 ms·

> And the CO2, even if it's invisible for us, is actually "black" for something important: it's blocking the part of the spectrum that would allow the Earth sur

> And the CO2, even if it's invisible for us, is actually "black" for something important: it's blocking the part of the spectrum that would allow the Earth surface to cool off. That's how small concentrations of it, compared to some other stuff in the air, produce such a big effect. > The physics is simple and undeniable, and it's known that there will be always more problems caused by the growth of CO2 in the atmosphere which increases the surface temperature of the Earth. Take a look at this graph of co2 vs temperature over a geological timescale: http://www.biocab.org/Geological_Timescale_op_712x534.jpg http://www.biocab.org/Geological_Timescale_op_712x534.jpg (from http://www.biocab.org/carbon_dioxide_geological_timescale.html http://www.biocab.org/carbon_dioxide_geological_timescale.ht...) From this, there doesn't seem to be any relationship at all and the co2 has been much higher during much of the history of earth. At the very least, you can't say that the relationship is simple.

acqq 8y ago
Take a look at who constructed the graph you quoted: http://citizenschallenge.blogspot.com/2012/10/nasif-s-nahle-google-scholar-and.html http://citizenschallenge.blogspot.com/2012/10/nasif-s-nahle-... Not a scientist. Now... anybody who is really interested in the real geological history knows that even the continents "weren't there" where they are now, when we look long enough in the past. Not to mention that, for the old enough times, not even plants existed on the land! https://en.wikipedia.org/wiki/Geological_history_of_Earth https://en.wikipedia.org/wiki/Geological_history_of_Earth In that context: https://www.skepticalscience.com/co2-higher-in-past-intermediate.htm https://www.skepticalscience.com/co2-higher-in-past-intermed... "However, until recently, CO2 levels during the late Ordovician were thought to be much greater than 3000 ppm which was problematic as the Earth experienced glacial conditions at this time. The CO2 data covering the late Ordovician is sparse with one data point in the CO2 proxy record close to this period - it has a value of 5600 ppm. Given that solar output was around 4% lower than current levels, CO2 would need to fall to 3000 ppm to permit glacial conditions." "(Young 2009). Rock weathering removes CO2 from the atmosphere. The process also produces a particular isotope of strontium, washed down to the oceans via rivers. The ratio of strontium isotopes in sediment layers can be used to construct a proxy record of continental weathering activity. The strontium record shows that around the middle Ordovician, weatherability increased leading to an increased consumption of CO2. However, this was balanced by increased volcanic outgassing adding CO2 to the atmosphere. Around 446 million years ago, volcanic activity dropped while rock weathering remained high. This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation." "So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008)." You have to understand geology to be able to compare. If you don't, people with agenda will easily sell you worthless graphs. Worthless as in "CO2 was higher when there were no plants and animals on the land at all, just the naked rocks." Nice target you have.
- topmonk 8y ago
  Thanks for the info. I'm sorry, you were right, that was a bad source. However, the rebuttal surprisingly leaves out a graph that directly shows temperature against glaciation, solar output and co2, but rather just talks about the comparison, without showing it. I don't find that particularly convincing of anything. Just because > "Around 446 million years ago, volcanic activity dropped while rock weathering remained high." it doesn't follow that > "This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation.", especially given that this simple graph of all 3 influences mentioned (sun output, glaciation, and co2 levels) against temperature isn't included. Do you know of a source that shows this? > "So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008)." Again, it's hard for me to take this seriously without seeing the comparison between the different forces that are identified against each other and temperature. It's like someone was peering at something through binoculars and said they saw an elephant. They offer as proof by stating, "I see a trunk, and a tail, and its tusks..", but they won't let you look through the binoculars yourself. (Also the Csank 2011 link gives a 404) The best I could find was https://www.co2levels.org/ https://www.co2levels.org/, which if you click the buttons in the top left, can be massaged in displaying co2 vs temperature for the last 800k years. And even in this period there are a few the temperature decouples from the co2 levels and mostly the temperature rise precedes the rise in co2, which makes one think that co2 entering the atmosphere is a effect of climate rather than a cause. > You have to understand geology to be able to compare. If you don't, people with agenda will easily sell you worthless graphs. Worthless as in "CO2 was higher when there were no plants and animals on the land at all, just the naked rocks." Nice target you have. I'm not saying the earth was the same as before. Just that the idea is that co2 is causing irreversible warming and that's that, isn't supported very well by the evidence I've seen. At best what you have given me shows that the co2 causing warming isn't entirely disprovable. I guess what I'm worried about is that the news often simplifies complex topics to, "it's a disaster!", or alternatively, "it's a hoax!" I don't think things are that simple, yet I haven't heard from anyone, scientist or no, that things are not either a "disaster" or a "hoax".

acqq 8y ago

Take a look at who constructed the graph you quoted: http://citizenschallenge.blogspot.com/2012/10/nasif-s-nahle-google-scholar-and.html http://citizenschallenge.blogspot.com/2012/10/nasif-s-nahle-... Not a scientist. Now... anybody who is really interested in the real geological history knows that even the continents "weren't there" where they are now, when we look long enough in the past. Not to mention that, for the old enough times, not even plants existed on the land! https://en.wikipedia.org/wiki/Geological_history_of_Earth https://en.wikipedia.org/wiki/Geological_history_of_Earth In that context: https://www.skepticalscience.com/co2-higher-in-past-intermediate.htm https://www.skepticalscience.com/co2-higher-in-past-intermed... "However, until recently, CO2 levels during the late Ordovician were thought to be much greater than 3000 ppm which was problematic as the Earth experienced glacial conditions at this time. The CO2 data covering the late Ordovician is sparse with one data point in the CO2 proxy record close to this period - it has a value of 5600 ppm. Given that solar output was around 4% lower than current levels, CO2 would need to fall to 3000 ppm to permit glacial conditions." "(Young 2009). Rock weathering removes CO2 from the atmosphere. The process also produces a particular isotope of strontium, washed down to the oceans via rivers. The ratio of strontium isotopes in sediment layers can be used to construct a proxy record of continental weathering activity. The strontium record shows that around the middle Ordovician, weatherability increased leading to an increased consumption of CO2. However, this was balanced by increased volcanic outgassing adding CO2 to the atmosphere. Around 446 million years ago, volcanic activity dropped while rock weathering remained high. This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation." "So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008)." You have to understand geology to be able to compare. If you don't, people with agenda will easily sell you worthless graphs. Worthless as in "CO2 was higher when there were no plants and animals on the land at all, just the naked rocks." Nice target you have.

topmonk 8y ago
Thanks for the info. I'm sorry, you were right, that was a bad source. However, the rebuttal surprisingly leaves out a graph that directly shows temperature against glaciation, solar output and co2, but rather just talks about the comparison, without showing it. I don't find that particularly convincing of anything. Just because > "Around 446 million years ago, volcanic activity dropped while rock weathering remained high." it doesn't follow that > "This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation.", especially given that this simple graph of all 3 influences mentioned (sun output, glaciation, and co2 levels) against temperature isn't included. Do you know of a source that shows this? > "So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008)." Again, it's hard for me to take this seriously without seeing the comparison between the different forces that are identified against each other and temperature. It's like someone was peering at something through binoculars and said they saw an elephant. They offer as proof by stating, "I see a trunk, and a tail, and its tusks..", but they won't let you look through the binoculars yourself. (Also the Csank 2011 link gives a 404) The best I could find was https://www.co2levels.org/ https://www.co2levels.org/, which if you click the buttons in the top left, can be massaged in displaying co2 vs temperature for the last 800k years. And even in this period there are a few the temperature decouples from the co2 levels and mostly the temperature rise precedes the rise in co2, which makes one think that co2 entering the atmosphere is a effect of climate rather than a cause. > You have to understand geology to be able to compare. If you don't, people with agenda will easily sell you worthless graphs. Worthless as in "CO2 was higher when there were no plants and animals on the land at all, just the naked rocks." Nice target you have. I'm not saying the earth was the same as before. Just that the idea is that co2 is causing irreversible warming and that's that, isn't supported very well by the evidence I've seen. At best what you have given me shows that the co2 causing warming isn't entirely disprovable. I guess what I'm worried about is that the news often simplifies complex topics to, "it's a disaster!", or alternatively, "it's a hoax!" I don't think things are that simple, yet I haven't heard from anyone, scientist or no, that things are not either a "disaster" or a "hoax".