[Bored chemist]

Only if it hadn't been done before.

When did you do it?

[alancalverd]

The literate among us will have read the rest of my reply in which I explained what needed to be done to test the hypothesis,and implied (OK, it was a subtle implication, but one that most scientists could spot) that the test obviously has not been done.Then I stated that it probably won't be done in the lifetime of anyone reading this.

[alancalverd]

temperatures will normalise themselves then

There is no normal. Never has been.

In almost every populated country (i.e everywhere but Antarctica) there was a period in recent history when the climate suited human occupation at a sustainable density. Right now it seems that the most-populous regions are moving into a period where that is not the case, and are doing nothing about it except demanding that  everyone else should solve the problem by making a sacrifice that may turn out to be futile anyway.

[Deecart]

If we assume humanity change climate due to C02 emmission.
Lets try some calculation.

Presence of CO2
CO2 ppm in atmosphere (measured at 4000m) :
1960 : 318 ppm
2020 : 410 ppm
Difference : 410-318 = 92 ppm
1 ppm is equivalent to 7.81 BT (Billion Tons) of CO2
92 ppm is equivalent of around 720 BT of CO2.

Emmission of CO2
1960 : 9.39 BT
1970 : 14.9 BT
1980 : 19.49 BT
1990 : 22.75 BT
2000 : 25.23 BT
2010 : 33.34 BT
2020 : 34.81 BT
Total : 159.91 BT
Multiply by 10 (because the amount above are the one the year showed every 10 years)
Total (around) : 1600 BT emmited from 1960 to 2020

How do this emmission land on atmosphere ?
Only 43 % of the emmission finish in atmosphere (the rest land elsewhere)
So 1600 BT *43% = 688 BT of CO2

Result
It is amazing to observe that we have almost perfect match between the global CO2 emission and the atmospheric CO2 raise (688 against 720)
 
Critisism
When the data match so well is it too good to be true ?

Lets try to verify roughly the CO2 emission data.
Coal : 6 BT used every year worldwide.
Oil : 4 BT used every year woldwide.
Total 10 BT used every year.
 
Question
How can we have 35 BT emission in 2020 when we use 10 BT Coal and Oil ?

Is mankind responsible of only 30 or 50% of the CO2 increase in atmosphere ?

[alancalverd]

Slight problem with your calculations. Coal is virtually pure carbon so each gram of coal burned produces 3.6 gram of CO2. Slightly less for oil, which contains a lot of hydrogen.

However there are some very significant anomalies.If you look at the data from Mauna Loa, for instance, you can see that the CO2 level rises in late spring and early summer, every year. But this is the time when human consumption of fuels is decreasing. My suggestion is that it is due to cold-blooded animals, particularly insects, waking up and turning plant  material into carbon dioxide  (i.e. living).

You also need to consider that the human population has increased since 1960, and humans exhale 10% of all the CO2 they produce. And the farm animal population has also increased enormously, which currently contributes 25% of anthropogenic CO2.

Full marks for trying, but I think you need to review your data. And where did you get that  43% figure?

[Petrochemicals (OP)]

I would disagree

You disagree that high temperatures make a drought worse?  Higher temperatures increase moisture loss from the soil which makes a drought worse, in that more plants will die from the drought.

good, temperatures will normalise themselves then

What do you think that means?  Normalize to what and why?

That temperatures have fluctuated.

Normalise - to return to the normal or usual situation

https://dictionary.cambridge.org/dictionary/english/normalize

Because you said it was an anomoly.

[Petrochemicals (OP)]

temperatures will normalise themselves then

There is no normal. Never has been.

In almost every populated country (i.e everywhere but Antarctica) there was a period in recent history when the climate suited human occupation at a sustainable density. Right now it seems that the most-populous regions are moving into a period where that is not the case, and are doing nothing about it except demanding that  everyone else should solve the problem by making a sacrifice that may turn out to be futile anyway.

Well Alan, the op had this image.


2000_years_with_error_v2.png (94.78 kB . 800x600 - viewed 2577 times)

As you can see there is a spike in temperatures above the past 1000 year fluctuations. I think it could be entirely possible that such spikes have happened before yet the evidence currently supplied does not support this. Although the grey area at the rear of the like is possibly the margin of error.

[Petrochemicals (OP)]

Slight problem with your calculations. Coal is virtually pure carbon so each gram of coal burned produces 3.6 gram of CO2. Slightly less for oil, which contains a lot of hydrogen.

However there are some very significant anomalies.If you look at the data from Mauna Loa, for instance, you can see that the CO2 level rises in late spring and early summer, every year. But this is the time when human consumption of fuels is decreasing. My suggestion is that it is due to cold-blooded animals, particularly insects, waking up and turning plant  material into carbon dioxide  (i.e. living).

You also need to consider that the human population has increased since 1960, and humans exhale 10% of all the CO2 they produce. And the farm animal population has also increased enormously, which currently contributes 25% of anthropogenic CO2.

Full marks for trying, but I think you need to review your data. And where did you get that  43% figure?

https://en.m.wikipedia.org/wiki/Carbon_cycle

[evan_au]

Only 43 % of the emmission finish in atmosphere (the rest land elsewhere)

Much of the rests lands on the 70% of not-land = 70% ocean & seas.
- It is making the oceans more acidic, which means that marine animals have to expend more energy maintaining bones and shells

A small amount actually lands on the 30% of land, and is slowly absorbed by rocks (eg basalt, like much of Mauna Loa).
- A larger amount is actively absorbed by trees on land, plants in peat bogs and algae in the oceans. How long it stays out of atmospheric circulation depends on whether the forest burns, the peat bog dries out, and whether the algae sinks to the bottom of the ocean.
- It is thought that the average residence time of CO₂ in the atmosphere is about a century.

Is global warming man-made?

I would say that women played a large part in it, too...

[Origin]

That temperatures have fluctuated.

Normalise - to return to the normal or usual situation

So your belief is that the current temperature rise will reverse and the earth will cool back down with no change in man's activity concerning greenhouse gasses.  Is that a correct description of your position?

Because you said it was an anomoly.

Yes, it is an anomaly caused by human activity.  This temperature anomaly will continue to increase as long as our current activity of pumping greenhouse gasses into the atmosphere continues.  If we were to suddenly stop dumping greenhouses gasses into the atmosphere the global temperatures would begin to decrease after some time.

[alancalverd]

So your belief is that the current temperature rise will reverse and the earth will cool back down with no change in man's activity concerning greenhouse gasses. 

It's a reasonable assumption based on previous history. Isn't that how science works?

Yes, it is an anomaly caused by human activity.

It may be, but the only actual evidence is that there is a recent unidirectional correlation. Proof of causation requires a bit more rigor.

[Petrochemicals (OP)]

Is global warming man-made?

I would say that women played a large part in it, too...

That statement is dangerously ambiguous Evan.

[Petrochemicals (OP)]

That temperatures have fluctuated.

Normalise - to return to the normal or usual situation
So your belief is that the current temperature rise will reverse and the earth will cool back down with no change in man's activity concerning greenhouse gasses.  Is that a correct description of your position?

Oh gosh no. It is my belief that when man stops using fossil fuels we will cause a catastrophic cooling event and the water cycle will freeze us, the earth is running on the midnight oil we will have no wiggle room. I predict famine war and pestilence as the earth freezes, the future will look like zombies with snow on. Let's face it global warming just means siberia and Canada will develop a pleasant climate.

But it is an interesting point that the margin of error in Earth's temperature is greater than the "increace" we are told about, the fact that a "megadrought" branded as global warming has happened before to a greater extent, that shock temperature increaces across the earth are off the back of a mini ice age. Are historical scientific measurements of Earth's conditions precise enough to measure a short 30 year spike in temperatures?

Essentially origin I am playing devil's advocate with the evidence of sediment cores from lake beds in North America. Can you prove that this sort of heat increace has not happened before in the last 10,000 years beyond 99% assurity, because these lake core sediments do cast doubt onto the 100 percent claim that global warming is a recent modern phenomenon.

Because you said it was an anomoly.
Yes, it is an anomaly caused by human activity.  This temperature anomaly will continue to increase as long as our current activity of pumping greenhouse gasses into the atmosphere continues.  If we were to suddenly stop dumping greenhouses gasses into the atmosphere the global temperatures would begin to decrease after some time.

Oh.

[Deecart]

Slight problem with your calculations. Coal is virtually pure carbon so each gram of coal burned produces 3.6 gram of CO2. Slightly less for oil, which contains a lot of hydrogen.

Yes you are right.
I forgot to multiply according to stoichiometry...
If i try to give the right answer the problem is not obvious, because of the different quality of coal.
So (without warranty) i will  use some rough estimation depending on the use of thise coals: I multiply coal by 2.7.
For oil, i suppose less, so 2.5.

Doing so we have 6*2.7 + 4*2.5 = 16.2 + 10 = 16.2
Let say 20 BT

So same result : Some global emission is missing.

However there are some very significant anomalies.If you look at the data from Mauna Loa, for instance, you can see that the CO2 level rises in late spring and early summer, every year. But this is the time when human consumption of fuels is decreasing. My suggestion is that it is due to cold-blooded animals, particularly insects, waking up and turning plant  material into carbon dioxide  (i.e. living).

Yes, there is also localy short variation of CO2 ppm but in my opinion this consideration only provide confusion.
When we try to understand the CO2 flow within one year it is very complicated.
CO2 need time to homogenize (if ever..) in the atmosphere, at the scale of the planet,
I found a nice video (NASA modeling using computers) showing this : 

You also need to consider that the human population has increased since 1960, and humans exhale 10% of all the CO2 they produce. And the farm animal population has also increased enormously, which currently contributes 25% of anthropogenic CO2.

Yes but i dont think you have to take this in account.
Because here "we" (also the cow) are part of a cycle (so net result is around 0).
It is not like the fossil fuel (coal and oil) that was inside earth and now in the atmosphere (there is a cycle for this CO2 too of course but surely million of years long, so at our time scale we can speak of a linear emission)..

Full marks for trying, but I think you need to review your data. And where did you get that  43% figure?

I found this on some blog where someone was doing some calculation like i did.
You can take 50% perhaps, i dont think we can give a % very accurate because of the intermediate time flow of CO2 (like in the ocean).
Here it is (it is in french) : https://gblanc.fr/spip.php?article731

Now perhaps there are other CO2 sources, that is not directly due to mankind.
Per example, deforestation and fires (due to mankind but not directly) is taken in account for 8% of CO2 emission (regeneration is long and actually for some equatorial forests very long (they never regenerate actually))..
Volcanoes part is around 0.3 BT
Etc.

[Origin]

Oh gosh no. It is my belief that when man stops using fossil fuels we will cause a catastrophic cooling event and the water cycle will freeze us, the earth is running on the midnight oil we will have no wiggle room. I predict famine war and pestilence as the earth freezes, the future will look like zombies with snow on.

that seems a bit far fetched.

Let's face it global warming just means siberia and Canada will develop a pleasant climate.

I live pretty far north so yeah it is kind of nice to have warmer weather.  It is rather unfair for the billions that will have their homes under water though, if nothing is done.

[Origin]

It's a reasonable assumption based on previous history.  Isn't that how science works?

There is no previous history of man made global warming.  It is also true that global temperatures vary over the course of geologic history.  They will vary in the future.  That is not what is being discussed here.
There has been a very rapid increase in global temperatures, experts in the field of climatology have looked at the data and have put forth a very convincing hypothesis for this unusually rapid rise in global warming.  This hypothesis indicates that if there is no change in the amount of greenhouse gases put into the atmosphere then the temperature will continue to rise.
That is how science works.

[alancalverd]

The present temperature is almost exactly what you would expect it to be if you had no other information than the Vostok ice cores. Yes, there has been a rapid increase in recent history but nothing unprecedented in the geological record or out of the geological time sequence. There has also been a rapid increase in human population and activity, but it is still a one-way correlation.

The most important greenhouse gas is water. As the temperature rises, so does the water content, so the rise accelerates. There is no other explanation for previous peaks. Problem is that it is out of our control.

[Kryptid]

First time (around 30 years ago) i heard about the possibility human could have change climate (instead of volcanoes or sun) some climatologist explained that within the solar system, the temperature of every planet changed (this was NASA facts)
Obvious explaination was : The sun changed the temperature.

Do you have a source for this?

[Origin]

The present temperature is almost exactly what you would expect it to be if you had no other information than the Vostok ice cores. Yes, there has been a rapid increase in recent history but nothing unprecedented in the geological record or out of the geological time sequence. There has also been a rapid increase in human population and activity, but it is still a one-way correlation.

The most important greenhouse gas is water. As the temperature rises, so does the water content, so the rise accelerates. There is no other explanation for previous peaks. Problem is that it is out of our control.

Well, I agree with the experts.[shrug]

[Deecart]

First time (around 30 years ago) i heard about the possibility human could have change climate (instead of volcanoes or sun) some climatologist explained that within the solar system, the temperature of every planet changed (this was NASA facts)
Obvious explaination was : The sun changed the temperature.

Do you have a source for this?

Sorry but the source has since disappeared.