The post on Watts Up With That titled
starts with the text
“There is quite a bit of buzz surrounding a talk and pending paper from Prof. Murry Salby the Chair of Climate, of Macquarie University. Aussie Jo Nova has excellent commentary, as has Andrew Bolt in his blog. I’m sure others will weigh in soon.
In a nutshell, the issue is rather simple, yet powerful. Salby is arguing that atmospheric CO2 increase that we observe is a product of temperature increase, and not the other way around, meaning it is a product of natural variation.”
My view is that the added carbon dioxide in the last century and up to the present, as documented at a variety of observation sites around the globe; e.g. see ESRL Global Monitoring Division, is indeed from human causes (industrial and vehicular emissions, biomass burning, etc.).
There is a new paper that could help further resolve this issue. The paper is
Sano, Y., Furukawa, Y. and Takahata, N. Atmospheric helium isotope ratio: Possible temporal and spatial variations. Geochimica et Cosmochimica Acta 74, 4893-4901, 2010.
The abstract reads [highlight added]
The atmospheric 3He/4He ratio has been considered to be constant on a global scale, because the residence time of helium is significantly longer than the mixing time in the atmosphere. However, this ratio may be decreasing with time owing to the anthropogenic release of crustal helium from oil and natural gas wells, although this observation has been disputed. Here, we present the 3He/4He ratios of old air trapped in historical slags in Japan and of modern surface air samples collected at various sites around the world, measured with a newly developed analytical system. In air helium extracted from metallurgical slag found at refineries in operation between AD 1603 and 1907 in Japan, we determined a mean 3He/4He ratio of (5106 ± 108) 10–5 RHESJ (where RHESJ is the 3He/4He ratio of the Helium Standard of Japan), which is consistent with the previously reported value of (5077 ± 59) 10–5 RHESJ for historical slags in France and United Arab Emirates and about 4% higher than that of average modern air, (4901 ± 4) 10–5 RHESJ. This result implies that the air 3He/4He ratio has decreased with time as expected by anthropogenic causes. Our modern surface air samples revealed that the 3He/4He ratio increases from north to south at a rate of (0.16 ± 0.08) 10–5 RHESJ/degree of latitude, suggesting that the low 3He/4He ratio originates in high-latitude regions of the northern hemisphere, which is consistent with the fact that most fossil fuel is extracted and consumed in the northern hemisphere.
The introduction starts with the text
The present terrestrial atmosphere has a helium concentration of 5.24 ppm by volume (Glukauf, 1946), which reflects an approximate balance between the supply from degassing of the solid Earth and thermal escape from the top of the atmosphere into space (Kockarts, 1973). Since the mixing time in the atmosphere is less than 10 years, much shorter than the residence time of helium, about 106 years, the atmospheric 3He/4He ratio has been considered to be globally uniform (Ozima and Podosek, 1983; Mamyrin and Tolstikhin, 1984). On this basis, most noble gas laboratories use air helium as an isotopic standard. Human activities such as oil and natural gas production and coal mining, however, may release non-negligible amounts of crustal helium with a low 3He/4He ratio (Oliver et al., 1984).
The text ends with the information
Because helium is chemically inert, further study of 3He/4He changes in space and time may provide a marker for calibration of the absolute flux and retention of anthropogenic CO2 in the atmosphere if we can separate production- produced helium from consumption-produced helium.
This is an important new study that should be followed closely.