Eat that GW believers!

[seedload]

Almost as silly as predicting 7000 ppm CO2 in a hundred years despite all evidence to the contrary.

Using the ice core figures above, rate of increase rose by 2.64 times from 12.4 ppmv / yr to 32.7 ppmv / yr in the 75 years between 1900 and 1975.

At that rate we reach 7,000 ppmv in 2350.

More recent figures get us there by 2200.

OK, I still don't agree, but at least you admitted you were wrong. Thanks.

[alexjrgreen]

Atmospheric CO2 levels are currently around 380 ppmv, rising at 2 ppmv per year.

30 years ago they were rising at 1 ppmv per year.

Assuming a doubling every 30 years, we would reach 7,000 ppmv in less than two centuries.

[TallDave]

Atmospheric CO2 levels are currently around 380 ppmv, rising at 2 ppmv per year.

30 years ago they were rising at 1 ppmv per year.

Assuming a doubling every 30 years, we would reach 7,000 ppmv in less than two centuries.

Again, there just isn't enough carbon-based fuel, and too much is reabsorbed every year. Even with wildly optimistic assumptions it's hard to get close to 7,000 ppm, even if we dumped every bit of it in one year.

[seedload]

CO2 has been up to 7,000 ppmv in geological time. No tipping point.

At that level it starts to become toxic to humans.

As that's only 18 times the current level, a combination of increasing human population and increasing per capita energy use will get us there within a century or so if we continue to release CO2.

Time for some alternative sources of energy. Fusion, perhaps...

[seedload]

Atmospheric CO2 levels are currently around 380 ppmv, rising at 2 ppmv per year.

30 years ago they were rising at 1 ppmv per year.

Assuming a doubling every 30 years, we would reach 7,000 ppmv in less than two centuries.

Even if you are going by this quote, you are again wrong.

CO2 will take about 850 years to get to 7000 ppm at current rates and ignoring all questions of sustainability.

regards

EDIT - Sorry, it might help to explain why you are wrong. First, the doubling took 40 years not 30 but that is not the big error. The big error is that the rate of CO2 increase is not "doubling" every 30 years. It is going up by 1ppm every 40 years (linear acceleration). The "doubling" from 1 ppm to 2 ppm was just because it started at 1, not because it actually doubled. In forty years (or so) from now it will be 3 ppm - not 4. In 60 it will be 4 not 8. Get it? The acceleration is linear. This is the actual trend. There is no doubling.



This is a projection of CO2 for the next eight hundred years using the above data and the linear acceleration. Again - assuming nothing changes and there are no limits.

[alexjrgreen]

CO2 has been up to 7,000 ppmv in geological time. No tipping point.

At that level it starts to become toxic to humans.

As that's only 18 times the current level, a combination of increasing human population and increasing per capita energy use will get us there within a century or so if we continue to release CO2.

Time for some alternative sources of energy. Fusion, perhaps...

within a century or so

[alexjrgreen]

seedload,

You're not using a long enough data series. You need to use the Law Dome figures to go back to 1825.

[Skipjack]

Yeah but in 1825 the CO2 output increased for all kinds of reasons. It was when industrial revolution came into full gear and steam engines became more wide spread. I am sure there was a pretty steep increase arround that time and after. While I dont have the data here, I would expect that curve to have become a lot less steep by the 1940ies though (when coal fired steam engines were replaced with more efficinet engines powered by oil and gasoline).

[Skipjack]

within a century?
You are off by an entire order of magnitude here. Even if it were to double again within the next 100 years, which it wont, we would only be a 0.076% (lets be generous and round it up to 0.08%).
At 1% you have mild effects like drowsiness (like in a crowded room with little ventilation). Below that pretty much no effect at all.
So if we assume 0.8% as a threshold, we would still be an order of magnitude away in 100 years, even if the increase was exponential instead of linear. Personally I believe that it will flatten off at some point.

[alexjrgreen]

Yeah but in 1825 the CO2 output increased for all kinds of reasons. It was when industrial revolution came into full gear and steam engines became more wide spread. I am sure there was a pretty steep increase arround that time and after. While I dont have the data here, I would expect that curve to have become a lot less steep by the 1940ies though (when coal fired steam engines were replaced with more efficinet engines powered by oil and gasoline).

The Industrial Revolution started small and accelerated. I've given you the data...

Historical CO2 record from the Law Dome DE08, DE08-2, and DSS ice cores

From 1010 to 1825 the 75 year average CO2 level meandered around between 275.3 and 284.3 ppmv.

After 1825 the level rose exponentially:

In the 75 years between 1825 and 1900 it rose 12.4 ppmv to 296.7

In the 75 years between 1900 and 1975 it rose 32.7 ppmv to 329.4

Trends in Atmospheric Carbon Dioxide - Mauna Loa

In only 25 years between 1975 and 2000 it rose 38.67 ppmv.

There was in fact a pause in CO2 levels during WWII, perhaps for the reason you give.

[alexjrgreen]

within a century?

Or so. In under two centuries.

You are off by an entire order of magnitude here. Even if it were to double again within the next 100 years, which it wont, we would only be a 0.076% (lets be generous and round it up to 0.08%).

For example:

2008 - 384
2013 - 395
2018 - 408
2023 - 422
2028 - 438
2033 - 456
2038 - 476
2043 - 498
2048 - 523
2053 - 552
2058 - 583
2063 - 619
2068 - 659
2073 - 704
2078 - 754
2083 - 811
2088 - 874
2093 - 946
2098 - 1,026
2103 - 1,115
2108 - 1,216
2113 - 1,329
2118 - 1,456
2123 - 1,599
2128 - 1,759
2133 - 1,938
2138 - 2,140
2143 - 2,366
2148 - 2,620
2153 - 2,905
2158 - 3,225
2163 - 3,585
2168 - 3,988
2173 - 4,440
2178 - 4,948
2183 - 5,518
2188 - 6,158
2193 - 6,877
2198 - 7,683

At 1% you have mild effects like drowsiness (like in a crowded room with little ventilation). Below that pretty much no effect at all.

Safe Use of Carbon Dioxide in Laboratories

So if we assume 0.8% as a threshold, we would still be an order of magnitude away in 100 years, even if the increase was exponential instead of linear. Personally I believe that it will flatten off at some point.

It will flatten off if we find a better way to generate power.

[seedload]

seedload,

You're not using a long enough data series. You need to use the Law Dome figures to go back to 1825.

You are suggesting I should use PROXY data from farther back in time instead of using measured data from recent time to determine the future trend of CO2 growth. Wow.

Nothing more to say to you.

[Jccarlton]

The only problem with the Law Dome cores is, well the volcano problem again:
http://www.antarcticconnection.com/anta ... ebus.shtml

http://wattsupwiththat.com/2008/01/22/s ... rctic-ice/

Now, I have to ask myself, looking a the law Dome data which sees no significant change in CO2 levels from the early 19th Century through the turn of the last century where steel and iron production expanded exponentially, through the 1920's with it's and economic boom and still increased in the Great Depression with lower economic activity and WW2 with yet more increase industrial activity, what exactly are these cores measuring? A great deal of change and yet no great change in the CO2 levels.

[Jccarlton]

I these people really believed the things they say about climate disaster, would they behave the way they do?:
http://wattsupwiththat.com/2009/12/01/t ... openhagen/

[kcdodd]

I got curious about it so I plotted this data you guys are talking about.

http://andromedaspace.com/files/CO2.pdf

If you look at the log-log plot its obvious the rate of increase is not linear, at least not continuously. But aside from that just taking the last 30 years at Mauna Loa and hold at that point, extrapolating you get up to ~700ppm in 2150, which agrees with seedload. But I still have the question if linearity is justified.