Saturday, May 2, 2015

update on what we know about threat of H2S killing us all

Five to ten times in past earth history (after the initial evolution of life) the levels of H2S and radiation on the land
reached levels which would kill every human on earth, if humans had been there at the time. Peter Ward, whose book Under a Green Sky
gives a good description of how that data is collected, believes that we are on course to reaching those levels again -- killing every human on earth.
Though I disagree with the details of Ward's THEORIES about the data, I for one do not intend to just ignore this threat. More and more, this is looking to me like the most likely "final trigger" likely to kill us all.

One of the IEEE people, from the IEEE Oceans Society, recently expressed worry that nutrients released from the biofuels industry are causing dead zones in the Caribbean. That seems very different from what Ward was saying -- but from the viewpoint of science I see them as pointing to the same tasks we really ought to be focusing on. When the much lesser threat of global warning surfaced years ago, Reagan was wise enough to say that we really ought to be studying the threat seriously, to try to understand how serious it is and what it depends on. With so much more at stake on the H2S front, it really should not be left to a part time hobby for a retired guy like me doing it alone, mainly focused on other topics! Still, I do keep trying to improve my understanding of this topic, and do have new thoughts to report.

The risk which concerns me most is the risk that the oxygen level in the deep waters of the southern Pacific
will get close enough to zero in about 40 years to cause a very sudden spurt in the growth of the specific type of microbe (a type of archaea)
which produces H2S. Ward gives various examples of places where that has already happened in a small area, and argues that this is what explains the mass extinctions of the past, which he is a leading expert on. That part of his story makes sense to me.

But then he gets politically correct. He notes a correlation between past extinctions and the rate of change of CO2, and speculates that ocean acidification is the "second trigger" which, combined with low oxygen in deep oceans, will kill us all.

At a conference yesterday on satellite data, I had a chance to speak to one of the Navy people, who has gotten a clear message from above that 
sea level rise is a major concern (guiding some of the data collection), but none of that other stuff. "But what about threats that could kill every human on earth? Are they a concern of anyone?" Response: a knowing look, and a question, "oh, are you talking about ocean acidification?"  In fact, since Ward has such high credentials in his field, as well as a powerful book aimed at the public, his theory that ocean acid is the trigger has had a strong impact on a certain circle of people. It has mainly just added energy to one of the existing factions in the climate debates.  But Ward is a paleontologist, not a chemist or a physicist. Why don't we have the kind of effort going to probe the competing explanations, and really try to learn what the implications are, instead of trying to act politically immediately without having any idea of what we are doing and what is really facing us?  This is really serious, for example, when data collection itself will have major blind spots.

Though I tend to doubt Ward's acidification theory, I still have deep respect for how he treated the subject in his book, which is far more satisfying to real scientific thinkers than most of what is published these days. He explained why he believes that theory, but he also cited other sources in a serious way, and emphasized the need for new crossdisciplinary research (especially on "thermohaline currents," the study of how levels of saltiness and temperature shape the currents which bring oxygen to the deep ocean, most of the time).

One of the sources he cites is a paper by Kump of Penn State, whose work seems to draw more respect than Ward's in those particular circles. 
In effect, Kump says: "Our bottom line worry is the proliferation of those archaea which produce H2S. That's what kills us. But these archaea are not such a mystery. To proliferate, they need just two things -- low oxygen levels, and a supply of nutrients." 

Even though I am theorist myself, I always ask: "What do the primary empirical data really tell us?" A year or two, I thought: "If it is that easy to get archaea and H2S proliferation, could we even see it (and model it) in an aquarium?" So I googled on 'stinky aquarium" -- and I didn't see anything to contradict Kump's idea. Lots of entertainment there, and maybe some possibilities for even a high school science project to be useful. (By the way, the Black Sea is another important test, though fortunately there is much less upwelling from there to the atmosphere than there is to the oceans. Still, I wonder what the chances are of a poison cloud striking Sevastopol or Istanbul in the night some day, causing an interesting international situation.)

There is pretty decent data on oxygen levels in the deep ocean. I was really stunned, a year or two ago, to learn that the issue is not "when will the oxygen-bearing currents by the Antarctic shut down?" Ward asked "what do the THC people have to tell us about the risk of stratified ocean?" That's not the issue, because it already happened! The new ice which guys like Inhofe crow about is due to the great wash of fresh water (which freezes much more easily than salt water, which is why we put salt on roads), water due to melting on the surface of the Antarctic, pouring into the ocean nearby. That same fresh water has simply zeroed out the current which bring oxygen to the deep ocean. The best maps I find on the web suggest we have about 40 years to go before it hits zero in the deep ocean, for the side which brings oxygen to the Pacific. It doesn't have to be zero on the surface for archaea to proliferate.

But it turns out that this happened before, even just a few thousands of years ago, before widespread human agriculture.
The risk is due to the COMBINATION of growing areas of low oxygen, and widespread (also growing) areas of nutrition
pouring into the ocean.

What would we need to be able to do a decent forecast (even stochastic) of how far away we are to a suddent tipping point when our extinction becomes assured? 

Before the last IEEE Energy Policy Committee meeting, I had a nice conversations with the oceans guy (who is welcome to identify himself if he chooses).  We began thinking.. it would be nice if we had a database, with "adequate' resolultion in three dimensiona nd time, of ocean oxygen and ocean levels of crucial nutrients such as phosphates, carbohydrates, iron, etc... aboveall the ones most important to archaea. Anticipating large dead zones has near-term benefits, as well as benefits in understanding the extinction possibility.  

But what could be done at minimum cost to get a better feeling for the risk than what I said on these lists?
How could we get such a database?

It would be nice if the DOD climate folks could add this to their radar. It is possible that the Navy already collects streams of data which simply require new back end analysis, to give us some better feeling. But the back end analysis might requtre some new research collaborations, to learn what new information could be extracted from the existing data either on its own or in combination with other data sources.

I was very interested yesterday in the presentations on "from Argos 3 to Argos 4," a report on plans for an ongoing productive 
collaboration on the Argos system of satellites. the French spaced agency (CNES) sgtarted this, and still leads the collablratoin, but the US, the EUMETSAT effort and now (as of 2007) India's ISRO all play important roles as well. I wonder whether and how soon the network of ocean-observing bouys they maintain could be expanded to measure ocean chemistry?

Some big US aerospace stakeholders were also there. They suggested that we could simply combine the ongoing data on oxygen levels (limited as it is) with data from satellites on chlorophyll obsderved on the surface. My initial reaction was pretty negative,
since archaea in the deep ocean aren't on the surface and they may have special nutrient vectors. However, BEFORE we have that kind of data, there may be some kind of statistical correlation (with error bars we need to know) between surface chlorophyll levels and the kind of nutrient variables which drive the growth of archaea. If we learn to understand those correlations better  
(with high school science experiments?), perhaps we could make better use of existing data, to give us at least a gross handle on the present threat and the future threats in the pipeline. The uncertainty bars may give at least some indication of the value of getting more and better data. 

In the end, this still begs the question: whether the new Great Dying begins 40 years from now or 100 or 200, what can we do about it? I pay more attention to that question than I do about the timing, but this email is already long, and it is best
for me to postpone that to other times and venues.

Best of luck,


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