The new data about the capacity of terrestrial carbon sinks to absorb our emissions that was discussed in Data Driven isn't the last word on the subject. It's an ongoing investigation.

Two new studies have looked at the issue, and they come to what appear to be very different conclusions.

Any process that removes carbon from the atmosphere can act as a carbon sink. These include basic processes like having the gas dissolve into the ocean, to more complex ones, like the sequestration that appears to take place in mature forests. The cumulative impact, however, is huge; carbon sinks are estimated to remove about 60 percent of the CO2 that human activity puts in the atmosphere annually. (The remaining 40 percent is termed the airborne fraction.) . . .

The uncertainty about when and to what degree the sinks would start to lose capacity has made them an active area of study. So it's no surprise that two papers that attempt to track the behavior of the sinks were published in rapid succession, one in Geophysical Research Letters, the second in Nature Geoscience. The surprise may be that they're being promoted as if they contradict each other.

Both papers use a similar methodology: total up the estimates of global emissions from various sources, and figure out what the airborne fraction is. The remainder has to be going into carbon sinks. But the two operate on very different time scales. The GRL paper starts all the way back in 1850, and comes to the conclusion that the airborne fraction has been increasing, but only by about 0.7 percent a decade; the uncertainties are nearly twice that, making it statistically indistinguishable from zero.

In contrast, the Nature Geo paper starts its analysis in 1960, when the post-war boom in carbon emissions was really kicking in. It sees a more pronounced trend, one of 0.3 ± 0.2 percent a year, which they say has a 90 percent probability of being statistically significant.

Why the difference? The rate of human CO2 emissions rises dramatically starting in 1960. By lumping those later years with data that extends back to 1850, the GRL paper runs the risk of having earlier data swamp more recent (and, arguably, relevant) trends. In addition, it necessarily extends into years where reporting on things like land use was sketchy or nonexistent, creating more significant uncertainties. . .

So, are carbon sinks beginning to reach their limits? Given the two papers, I have to admit I lack the expertise to judge.

What is clear, however, is that two extremely cautious and technical papers have been handled awkwardly from a media perspective. The GRL paper was heralded with a press release that touted it as "Controversial new climate change data," even though it didn't directly address climate change, and actually applies new methods to existing data sets. Two articles removed from the press release, and you end up with an article that claims "new research shows that atmospheric levels of CO2 have effectively remained unchanged since the advent of the industrial revolution." It's hard to imagine anyone getting it so badly wrong.

This seems to have prodded Nature publishing to respond; normally, Nature Geoscience papers are released on Sundays. An exception was made to release this one on a Tuesday, accompanied by a press conference. One of the universities involved also felt compelled to issue a press release. The title on this one was at least accurate, but focused on carbon emissions when these figures are widely estimated and reported already.

These are two highly technical papers that use different data sets and different methods; it's no surprise that they've reached different conclusions, and it will probably take the scientific community a few months of digesting them and comparing them to previously published work in order to reach a consensus on which one (if either) is likely to better reflect reality. Using them to generate competing coverage in the popular press doesn't do a public that understands climate science poorly any favors.

Oliver laments the sparse data available.

Now there’s some fascinating stuff in this, which I may come back to, but there’s also cause for deep frustration. A real sense of what the sinks are doing would be hugely helped by having better measurements of carbon dioxide, both from global monitoring networks and from satellites. But that just doesn’t seem to be a priority. Global ground based monitoring of carbon dioxide capable of showing regional effects is still underfunded — this summer in Boulder Pieter Tans was telling me that there was a lot more that could be done for relatively little money. And satellite measurements took a terrible blow when the Orbiting Carbon Observatory, OCO, didn’t make it to orbit in February. OCO could have been rebuilt and relaunched quickly: the team was all still there,the designs were good, it was as shovel-ready a piece of spending as you could wish for. But it wasn’t funded as such, and doesn’t seem to have any new money associated with it. So as I understand it the money to refly OCO will have to be gouged out of NASA’s existing earth science budget (8% of its total budget, because it’s not like the earth is a sexy supernova or galaxy or anything like that). I have to assume that that means it will fly later than it could have (and cost more); that probably means delays for SMAP, the soil moisture mission currently due to launch in 2013. SMAP would provide unparalleled data on one of the key parts of the planet — the part just beneath our feet that contains the root zones of plants and the water that those roots require.

Not to be treating such missions as a global priority strikes me as simply crazy.

I'm for more data. If I was Emperor of Earth I'd order all of my minions to seek and publish data, and order my librarians and data keepers to work diligently to make it easily and freely available to all who wish to see it. I'd be heralded in song - after my passing - as the good philosopher king who may not have done much of note but made it easier for others to do things.

However, there are no Emperors of Earth and there are no prospects of any. Those who speak of "global priorities" skip that awkward truth. Some of them are sincere but dysrational, others are opportunists who exploit the sincere ones for personal gain and the advancement of decidedly non-global agendas.

A more rational and likely more effective way to advocate for more data of this sort would be to cite the immediate, practical benefits of having the data to solve current local problems. Such data would assist with the type of applications discussed in Junk Signals. The clever hacks mentioned there - using existing GPS data to deduce moisture conditions, and using light from pulsing laser diodes reflected off plants to deduce plant health - could be enriched further by systems such as SMAP. Ka-ching! Money in the bank. Fly that bird right away. It could pay for itself, though the costs are socialized while the profits are capitalized. Is that a feature or a bug? Whatever. The way forward is to drop the "global priorities" talk and emphasize current utility.