Theories and facts are not always seperate things. Or what do you say about heliocentric theory, the theory that the earth orbits the sun? And Evolution is a Fact and a Theory

The big bang is equally fact and theory. "theory" in science doesn't mean hunch or guess. It means an explaination that has been well grounded in testing. Most scientific facts aren't 100% proven, they are based on overwhelming evidence. Anything in science could be overturned tommorow potentially, even the facts of today.

But I accept that. From my point of view your argument is analogous to saying we don't understand the climate 100% so we cannot be certain why summer happens. It's based on the same argument that because we don't know everything about climate, we cannot know any aspect of climate with any certainty.

I give the numbers acknowledging that they have error margin, but also pointing out that the error margin would have to be very large to overturn the final result of the calculations, and that is highly unlikely.

The fact remains that to make the relevant calculations you need the relevant data, not all data which also includes much irrelevant data.

This is what I mean about irrelevant data. It's like saying that to work out the cause of someone's bank balance increasing you need to understand the total amount of money on earth. You don't. There is information you need, but that's not a part of it.

The total amount of carbon locked away in the ground is irrelevant to the cause of the recent co2 rise. What is relevant is how much carbon is going in and out of the atmosphere over time. Seeing as the amount of carbon locked up in the earth as fossil fuels doesn't even help give this figure, it has absolutely no relevance.

Going back to the bank account analogy, you can use exactly the same method to find out whether a certain person has caused a recent rise in the bank balance. You only need to know 3 things:

1) How much the bank balance has risen in that time period (eg $150)
2) How much money that person has deposited into the account (eg $200)
3) Were they despositing prior to the increase? No

That is all. In this case the person's unique deposit in that time totals more money than the account balance has risen. Therefore this shows that the rise was due to them. Without them coming along and adding a unique contribution of $200, it couldn't possibly of risen $150. This is where the analogy of your counter argument comes in:

"you can't prove that. If they hadn't added $200, it might have risen anyway due to someone else putting it in".

Technically that is true, but it's beside the point. They caused the rise so it's valid to say without them putting it in the account couldn't have risen.

This example also tells you that all other entities (and notice we don't need to know anything about them) have the net effect of removing $50. Otherwise the account would have risen by the full $200 added, not just $150.

All of this must be true. It would defy mathematics for it not to be so.

So you don't need to know how much other sources are putting in and taking out. You don't need to know how the chaotic non-linear economic system works. You don't need to know how much total money is locked up in the world. You only need to know those three figures above to figure out whether a given entity has been the cause of the rise.

We know those 3 figures in terms of climate and can do the same thing there.

These figures are accepted by the scientific community. You could of course use the same argument to cast doubt on the age of the earth by saying that the date is not known, it is just an estimate based on radiodating, which is basedon what we currently know about using radioisotopes to measure age. You could similarly point out that "recent studies" have cast doubt on dates of something obtained by radiodating. But the earth is still approx 4.5 billion years old with severely little chance of being just 100,000. And the atmospheric concentration of co2 is still approx 280ppm 250 years ago with very little chance of being 340ppm.

There is absolutely nothing to suggest inaccuracy that high, and co2 trends from ice cores in antarctica correlating with co2 trends from ice cores in greenland suggest they are no where near that inaccurate.

The first is possible. The second, given modern sensitive equipment is directly measuring atmospheric levels is virtually impossible. Either way you have gone in the wrong direction by implying the co2 rise since 1750 might have been just 80ppm instead of 100ppm. What you need is a large rise that human emissions fall short of, not a smaller rise that human emissions easily cover.

Yes it could be.

Because I can tell for myself it doesn't make a difference. You need human emissions to be off by about 50% to not exceed the recent co2 rise, and most of that 1100gT co2 emissions has occured in recent decades when estimates of fossil fuel production have been very accurate (no way off by even 10%). As that is directly proportional to amount of co2 burnt, that figure cannot be off by any more than that.

Given that they have rounded to the nearest 100gt, I would say that was their maximum error rate (ie about 10%) which is as I expect given the source of their data.

It is a big number, and there are estimates for that too.


There is nowhere you find numbers that validate humans have only emitted 500 billion tons co2 over the past 250 years, and nowhere you can find numbers that validate co2 levels only rising 50ppm in the last century.

I put 200 marbles in the box (give or take 10). There were 280 marbes in there before (give or take 10). Now there are 380 marbles in the box. There should have been 480 marbles in the box. Yes the box must be eating the marbles.

That is far less likely than our lack of understanding of sinks being the cause. co2 today is measured extremely accurately. You can even see the rise and fall in atmospheric co2 levels during winter and summer (due to the change in temperature). It's beyond doubt that co2 really is rising at about 2ppm per year, and that it has risen 60ppm since 1960 to 380ppm today. Now it's hardly strange for ice core data to indicate it drops further down all the way to 280ppm much earlier than that.

Yes, but it is highly unlikely that these measurements are off by 50%.

Yes! our understanding of overall in and out of the atmopshere and amount of co2 in the atmosphere is extremely good. much better than our understanding of ins and outs and amounts of carbon in other areas such as the oceans and forests. In the atmosphere co2 is a well mixed gas, meaning it's a lot easier to get a representative sample of the entire atmosphere so you can know it's level and how it changes more easily over time. Plants and soils are far more difficult.

We aren't making definitive conclusions about the entire carbon cycle - only the atmosphere, which is ok because we know enough to be able to do that about the atmosphere.

I didn't claim that was a linear relationship and the ratio given represented it. I pointed out that a certain change from 280-270ppm at a certain time occured due to <1C temprature change. Only to point out that a 1C temperature change cannot be supported as causing the 100ppm rise observed.

The whole basis of my position is that those estimates are accurate enough to reach the conclusion. Mainly because for the conclusion to be wrong those estimates would have to be way off.

No I am simply pointing out that for the past few decades the rise has been between about 1.5-2ppm per year. There are no error rates involved in this case - that is a very accurate figure. We know levels in 1980 and we know them today. That part of the rise cannot even be off by 10%.

Standard deviation given for any particular monthly average (http://www.cmdl.noaa.gov/projects/we.../co2_mm_gl.dat) is 0.10ppm (excluding the last 2 months which are always more - 0.17 ppm and 0.57 ppm it says Global Monitoring Division)

Today co2 levels are 380ppm. 10 years ago they were 360ppm. Now we might say 10 years ago they were 359-361ppm and now they are 379-381ppm, but that's still generally a 18-22ppm rise.

The problem I have is that you think they could do that. As if those scientists studying this data haven't figured out the errors void their conclusions. They are the first people who would know if the conclusions were shakey.

There's a graph here that reflects this:
Climate Change 2001: The Scientific Basis