Carbon Dioxide Levels Reach 400 ppm: Not Seen in Three Million Years (dollars, elect)
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The last time the CO2 level was at 400ppm, sea levels were 80 feet higher. Where's the flooding?
The last time CO2 levels were 400 ppm there was no ice-age, like there is today. The last time CO2 levels were 400 ppm was ~3 million years ago. The current ice-age began 2.588 million years ago. Hence, a great deal of fresh water is still locked up in ice on land. For example, 85% of the land in Alaska is permafrost. Not all ice is located on the surface.
Nope, you've got the quote wrong, but I applaud you for quoting James Hanson. I thought the conservatives hated him, but you must think he's pretty cool :
"Unless greenhouse emissions are curbed, average global temperatures can climb two to three degrees Celsius by 2100. The last time the earth was that warm, sea levels were 80 feet higher than today"
Hanson did not take into consideration that when sea levels were 80 feet higher than today the planet was not experiencing an ice-age. However, today we ARE in an ice-age, and that is why sea levels are not 80 feet higher today.
The last time the CO2 level was at 400ppm, sea levels were 80 feet higher. Where's the flooding?
I always thought you a smart poster. Surely you can reason better than this.
The time lags in earth systems, due to their sheer mass, are decades to hundreds of years. It is like getting dosed with radiation. The tumors don't erupt the same day, but he seeds are sown through genetic mutations. As we are sewing the seeds for our grandchildren's suffering now. I don't know exactly what will happen, but temperature and flooding are lagging indicators, as plenty of research and a minute of thought would tell you.
The sea is rising, but it will take a very long time for enough ice to melt, and enough thermal expansion to occur in ocean waters to get an 80-foot rise. That couldn't happen for hundreds of years even in a worst case scenario.
It is unlikely the sea levels will rise 80 feet until after this ice-age ends. The ice-age will only end when the continent of Antarctica is ice free, anywhere from 2.5 to about 7.5 million years from today. Past ice-ages seem to span between 5 and 10 million years, and we are only 2.588 million years into the current ice-age.
Even though modern humans have been around for about 180,000 years, civilization did not begin until about 10,000 years ago. That almost coincides with the beginning of the Holocene Interglacial Period which we have been enjoying for the last 11,400 years. However, interglacial periods never last very long (relatively speaking), maybe 15,000 to 20,000 years before the mean surface temperature of the planet drops by around 6°C again.
From 1950 to 2009, measurements show an average annual rise in sea level of 1.7 ± 0.3 mm per year, with satellite data showing a rise of 3.3 ± 0.4 mm per year from 1993 to 2009,[SIZE=2][5][/SIZE]
I always thought you a smart poster. Surely you can reason better than this.
The time lags in earth systems, due to their sheer mass, are decades to hundreds of years. It is like getting dosed with radiation. The tumors don't erupt the same day, but he seeds are sown through genetic mutations. As we are sewing the seeds for our grandchildren's suffering now. I don't know exactly what will happen, but temperature and flooding are lagging indicators, as plenty of research and a minute of thought would tell you.
The point is the scare tactics used by the media. They aren't designed for those literate and educated - they are designed for the masses of uneducated or scientific illiterates.
I've seen the 400ppm number used for 15 years - not much has changed over the last 50ppm. In 1999 I was at a conference in Boston. The discussion at that time was the runways at Logan could be under water in 10 years. There was major concern about the Big Dig flooding. Nothing has changed. Nobody really knows.
Some people also forget about this little thing called evolution. Maybe, just maybe, humans 2000 years from now will thrive at 500ppm. Or maybe we will die off. Either way, nature isn't too worried about a few billion hominids.
I went to India - they drink water that would make a westerner violently ill. They begin developing the immunity and bacteria in their gut before birth. The inhabitants of Peru thrive in low oxygen. Runners from Africa win the marathons for a reason.
The point is the scare tactics used by the media. They aren't designed for those literate and educated - they are designed for the masses of uneducated or scientific illiterates.
I've seen the 400ppm number used for 15 years - not much has changed over the last 50ppm. In 1999 I was at a conference in Boston. The discussion at that time was the runways at Logan could be under water in 10 years. There was major concern about the Big Dig flooding. Nothing has changed. Nobody really knows.
Some people also forget about this little thing called evolution. Maybe, just maybe, humans 2000 years from now will thrive at 500ppm. Or maybe we will die off. Either way, nature isn't too worried about a few billion hominids.
I went to India - they drink water that would make a westerner violently ill. They begin developing the immunity and bacteria in their gut before birth. The inhabitants of Peru thrive in low oxygen. Runners from Africa win the marathons for a reason.
CO2 levels have to be greater than 20,000 ppm (2%) before humans will even notice. The last time CO2 levels were higher than 20,000 ppm was Precambrian, more than 540 million years ago. Long before plants on land or complex life evolved.
Photosynthesis stops when CO2 levels drop below 225 ppm. Ideally plants prefer between 500 ppm and 1,500 ppm of CO2 in the atmosphere. Given enough minerals, photosynthesis doubles when CO2 levels are 1,200 ppm.
Most office buildings range from 600 ppm to 900 ppm CO2. A packed conference room could reach 1,200 ppm CO2 or higher.
A CO2 level of 400 ppm in the atmosphere is nothing to humans.
CO2 levels have to be greater than 20,000 ppm (2%) before humans will even notice. The last time CO2 levels were higher than 20,000 ppm was Precambrian, more than 540 million years ago. Long before plants on land or complex life evolved.
Photosynthesis stops when CO2 levels drop below 225 ppm. Ideally plants prefer between 500 ppm and 1,500 ppm of CO2 in the atmosphere. Given enough minerals, photosynthesis doubles when CO2 levels are 1,200 ppm.
Most office buildings range from 600 ppm to 900 ppm CO2. A packed conference room could reach 1,200 ppm CO2 or higher.
A CO2 level of 400 ppm in the atmosphere is nothing to humans.
You really don't understand....... A level of CO2 doesn't affect us directly, but indirectly through our modern way of life. CO2 is a factor in climate change, and climate is important to us. We can't just shift our agricultural cheaply or easily if water issues are further exacerbated by climate change. Our only choice is to adapt or perish.
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