The reason the estimate range from 9-32% is that the effect of CO2 varies depending on the level of water vapor in the atmosphere and any particular location. When the air is extremely dry then CO2 may well cause (using your numbers) 32% of the greenhouse effect. The the relative humidity is 100% and clouds come into play then CO2 may only be 9% of the greenhouse effect. Water vapor is the majority of the greenhouse effect but it has no power to drive climate change on its own. Its level in the atmosphere is dependent on temperature and it can never rise above the 100% humidity level.
No one is proposing removing all the of CO2 from the atmosphere. All that would do is give us a snowball Earth (iced over from pole to equator). We just need to move it back down to the range it's been in for the last million years.
Not really. It's patently obvious on the face of it that without the Sun the Earth's climate would be dramatically different. It would be cold enough to condense oxygen and nitrogen for instance. The issue in question is have there been enough changes to the Sun's output to account for the climate changes we've seen and the answer is no.
What the hell is "MEP". Are you referring to the Maunder Minimum? The knowledgeable "AGW crowd" does not dismiss the effects of the Sun on Earth's climate at all. They just look at the detailed records we have of recent solar activity and see that there has not been enough change in solar output to cause the changes to the global climate that have occurred.
The issue there is mostly the misuse of antibiotics in animal feed and by prescription when it isn't warranted. Proper use of antibiotics is a good thing.
I don't think 1,500 years is a general consensus yet. That is from a recently published paper that while peer reviewed hasn't been fully vetted by the wider community yet. Let's see what they're saying about it in 6 months.
The number I've seen most often in the last 5 years is that we have ~22,000 years to the next glaciation. The Wikipedia article on present and future Milankovitch Cycles throws around some numbers like 50,000 years and 130,000 years and up to 620,000 years. It's obviously an area with a lot of uncertainty at this point that needs more study. I agree though that current levels of CO2 in the atmosphere probably preclude a new glaciation developing under any foreseeable conditions.
You fail to understand the physics of water vapor and carbon dioxide. I don't care how much water vapor humans pump into the atmosphere, it's not going to affect global water vapor levels all that much. The only way to significantly reduce the amount of water vapor in the air is to cool it so the water precipitates out. I understand that people are afraid that reducing CO2 emissions will destroy their way of life but I just think that's a lack of imagination.
Just to be clear, I believe it will be at least 200 years before we could force 50 feet of sea level rise. Before that happens we'd likely do something about global warming. So I don't expect that to happen, certainly not in the lifetime of anyone who is alive today (assuming no immortality treatment).
Well, by the definition of geologists we are in an ice age right now and will be as long as there are any significant ice caps in the polar regions. Currently we are in an interglacial period When the ice advances it's called a glacial period.
If the next glaciation isn't predicted to start for 1500 years* let them worry about it in 1000 years. 1500 years ago is like the year 612 AD. Nobody alive today has to worry about another ice age.
* I've heard other number like 20,000 years before the next glaciation starts but it's an area with a lot of uncertainty.
Notice I said "assuming there is water available to evaporate". That covers the reason that deserts are dry.
Humans can affect water vapor in the atmosphere regionally a little. For instance there is an increase in humidity near large reservoirs in arid regions such as Lake Mead and Lake Powell on the Colorado river. But once you get a couple hundred miles away the effect disappears. If you set a large nuclear reactor in the ocean and set it up to evaporate the maximum amount of water it could it still wouldn't affect global atmospheric water vapor levels to any extent. It would all precipitate out within a few hundred miles. A climatologist did a thought experiment once about what would happen if you could remove 100% of the water vapor from the atmosphere. Ignoring secondary effects he calculated that from 0% water vapor it would only take about 60 days for water vapor to return to normal levels. Humans just can't significantly affect water vapor levels in the atmosphere.
Keep displaying your ignorance. Ice cores over the last 800,000 years have not shown CO2 concentrations in the atmosphere above about 300 ppmv. This year the concentration is about 390 ppmv. The key phrase was up to 50 million climate refuges. As to the rest of your stuff you're going to have to document it. I suspect the Canadians would laugh you out of the room with your statement that "arctic ice has not melted to what it was in 1940-1945".
Humans have no control over the amount of water vapor in the atmosphere. The average lifetime of a water molecule in the atmosphere is 2 or 3 days. If there's more water vapor than the atmosphere can support at its current temperature the water will precipitate out. If there's less water vapor than the current temperature can support then water will evaporate into the atmosphere assuming there is water available to evaporate.
Actually, the Earth's tilt does change, just not enough to seriously affect the length of growing seasons over human time scales. That tilt is part of the Milankovitch Cycles that are thought to trigger the change from glaciation to interglacial and back.
Think again! Glaciers may cover a lot of existing land but as the glaciers build up sea level drops. At the height of the last glaciation it was over 200 feet lower than it is now. That exposes a lot of land that is currently under water including the Black Sea basin which were dry with Dead Sea like lakes at the bottom before sea level rose enough to flood it. I don't know which one wins out but it's not a given that glaciation leads to less exposed soil around the globe.
Slashdot Mirror
The reason the estimate range from 9-32% is that the effect of CO2 varies depending on the level of water vapor in the atmosphere and any particular location. When the air is extremely dry then CO2 may well cause (using your numbers) 32% of the greenhouse effect. The the relative humidity is 100% and clouds come into play then CO2 may only be 9% of the greenhouse effect. Water vapor is the majority of the greenhouse effect but it has no power to drive climate change on its own. Its level in the atmosphere is dependent on temperature and it can never rise above the 100% humidity level.
No one is proposing removing all the of CO2 from the atmosphere. All that would do is give us a snowball Earth (iced over from pole to equator). We just need to move it back down to the range it's been in for the last million years.
Citation needed
Not really. It's patently obvious on the face of it that without the Sun the Earth's climate would be dramatically different. It would be cold enough to condense oxygen and nitrogen for instance. The issue in question is have there been enough changes to the Sun's output to account for the climate changes we've seen and the answer is no.
What the hell is "MEP". Are you referring to the Maunder Minimum? The knowledgeable "AGW crowd" does not dismiss the effects of the Sun on Earth's climate at all. They just look at the detailed records we have of recent solar activity and see that there has not been enough change in solar output to cause the changes to the global climate that have occurred.
Kind of like the prediction that Himalayan glaciers would be melted by 2030 in the IPCC AR4 report. /snark (Sorry, I couldn't help myself.)
The issue there is mostly the misuse of antibiotics in animal feed and by prescription when it isn't warranted. Proper use of antibiotics is a good thing.
I don't think 1,500 years is a general consensus yet. That is from a recently published paper that while peer reviewed hasn't been fully vetted by the wider community yet. Let's see what they're saying about it in 6 months.
The number I've seen most often in the last 5 years is that we have ~22,000 years to the next glaciation. The Wikipedia article on present and future Milankovitch Cycles throws around some numbers like 50,000 years and 130,000 years and up to 620,000 years. It's obviously an area with a lot of uncertainty at this point that needs more study. I agree though that current levels of CO2 in the atmosphere probably preclude a new glaciation developing under any foreseeable conditions.
You fail to understand the physics of water vapor and carbon dioxide. I don't care how much water vapor humans pump into the atmosphere, it's not going to affect global water vapor levels all that much. The only way to significantly reduce the amount of water vapor in the air is to cool it so the water precipitates out. I understand that people are afraid that reducing CO2 emissions will destroy their way of life but I just think that's a lack of imagination.
Just to be clear, I believe it will be at least 200 years before we could force 50 feet of sea level rise. Before that happens we'd likely do something about global warming. So I don't expect that to happen, certainly not in the lifetime of anyone who is alive today (assuming no immortality treatment).
Oops!
Well, by the definition of geologists we are in an ice age right now and will be as long as there are any significant ice caps in the polar regions. Currently we are in an interglacial period When the ice advances it's called a glacial period.
That's an interesting hypothesis. Now you need to do the scientific research to make it a scientific theory that has some actual evidence behind it.
Arggggh! Of course I meant "as", not "and".
If the next glaciation isn't predicted to start for 1500 years* let them worry about it in 1000 years. 1500 years ago is like the year 612 AD. Nobody alive today has to worry about another ice age.
* I've heard other number like 20,000 years before the next glaciation starts but it's an area with a lot of uncertainty.
Notice I said "assuming there is water available to evaporate". That covers the reason that deserts are dry.
Humans can affect water vapor in the atmosphere regionally a little. For instance there is an increase in humidity near large reservoirs in arid regions such as Lake Mead and Lake Powell on the Colorado river. But once you get a couple hundred miles away the effect disappears. If you set a large nuclear reactor in the ocean and set it up to evaporate the maximum amount of water it could it still wouldn't affect global atmospheric water vapor levels to any extent. It would all precipitate out within a few hundred miles. A climatologist did a thought experiment once about what would happen if you could remove 100% of the water vapor from the atmosphere. Ignoring secondary effects he calculated that from 0% water vapor it would only take about 60 days for water vapor to return to normal levels. Humans just can't significantly affect water vapor levels in the atmosphere.
Of course that's the high temperatures for the day. What is the average temperature for the whole day? How much does it cool down overnight?
Keep displaying your ignorance. Ice cores over the last 800,000 years have not shown CO2 concentrations in the atmosphere above about 300 ppmv. This year the concentration is about 390 ppmv. The key phrase was up to 50 million climate refuges. As to the rest of your stuff you're going to have to document it. I suspect the Canadians would laugh you out of the room with your statement that "arctic ice has not melted to what it was in 1940-1945".
It may well be that 100 years from now global warming deniers are looked upon with the same disdain and holocaust deniers.
Humans have no control over the amount of water vapor in the atmosphere. The average lifetime of a water molecule in the atmosphere is 2 or 3 days. If there's more water vapor than the atmosphere can support at its current temperature the water will precipitate out. If there's less water vapor than the current temperature can support then water will evaporate into the atmosphere assuming there is water available to evaporate.
That works up to a point but what about when your sea walls get to be 50 feet high?
Sorry, it doesn't work that way unless that straw is small enough that capillary action takes over, and even then I think there are limits.
They probably go back to sand dunes once the Ogllala Aquifer is pumped out.
Actually, the Earth's tilt does change, just not enough to seriously affect the length of growing seasons over human time scales. That tilt is part of the Milankovitch Cycles that are thought to trigger the change from glaciation to interglacial and back.
Think again! Glaciers may cover a lot of existing land but as the glaciers build up sea level drops. At the height of the last glaciation it was over 200 feet lower than it is now. That exposes a lot of land that is currently under water including the Black Sea basin which were dry with Dead Sea like lakes at the bottom before sea level rose enough to flood it. I don't know which one wins out but it's not a given that glaciation leads to less exposed soil around the globe.
The temperature has to get above 37C before it's above normal human body temperature. That's uncommonly hot for anyplace near the sea.