A comprehensive new review of research on episodes of carbon-driven disruption of ocean and climate conditions over the last 300 million years shows the power of a big pulse of carbon dioxide to profoundly affect the environment.

The review, which is being published in the journal Science on Friday, concludes that the human-driven buildup of carbon dioxide under way now appears to be far outpacing past natural events, meaning that, for ocean chemistry particularly, the biological implications are potentially enormous — and laden with the kind of uncertainty that is hard to see as a source of comfort.

The paper grew out of a big 2010 workshop on “Paleo-ocean acidification and carbon cycle perturbation events” — junctures in earth history in the last several hundred million years when some great disturbance — such as spasms of volcanic activity — set off a big buildup of carbon in the atmosphere and oceans, driving climate change and pushing surface ocean waters toward the acid side of the pH scale. Click here for the agenda and presentations that built the foundation for the new paper.

There’s plenty of basic background on the new study in a news releases from Columbia University, available as a pdf here. [I’ll add links to news coverage as it appears.]

Bryan Lovell, the president of the Geological Society of London, was not involved in the research review but said in an e-mail message that the analysis strongly supports the society’s 2010 statement on the the significance of human-driven climate change — a statement drawing almost entirely on evidence etched in stone.

With that in mind, it’s worth digging in to a discussion Lovell and I had when I attended the first international conference on the Anthropocene, the idea that humans have become a dominant influence on vital Earth systems. Among other things, Lovell explains that the geological argument for the power of carbon dioxide is the one that he would take into a bar in Midland, Tex., to debate skeptical peers (his background is primarily in petroluem geology and he worked for decades in the oil industry).

A video of our chat is below, followed by some transcribed excerpts. I encourage you to listen and not just read. Lovell is an engaging and plain-spoken man whose views, I think, you’ll appreciate regardless of your stance on the science and policy options. [4:56 p.m. | Updated He’s also written “Challenged by Carbon,” a book on his climate diagnosis and prescription. ]

Here’s Lovell on the basics of the geological argument for the power of carbon dioxide to cause enduring changes in climate and the environment:

The beauty of looking in the rock record is you don’t have to run a computer model to see what’s going to happen. You see the whole thing. When you put say 2,000 gigatons [billion tons] or thereby of carbon into the atmosphere rapidly a certain number of things happen. It gets hot. The oceans get acid. They run short of oxygen and as a result quite a number of animals become extinct. And in the rock record what you see subsequently is the extinction event is recorded, and you see the draw-down over a period of 100,000 or 200,000 years of the carbon from the atmosphere, which is manifested on the floor of the ocean as a development of a carbon-rich mudstone. It’s just a very fine-grained rock. It’s just a stinking black mud laid down on the floor of the ocean.

The people who are saying to us, we’re carrying out an experiment with Earth and we don’t really know the outcome, well that sounds dramatic but strictly speaking it’s not true. Earth itself has run the experiment several times — 183 million years ago, something very comparable.

The fascinating thing that seems to be emerging is, as we look at … the 1,000-year timescales going back to 183 million years, other past warming events where we get these black mudstones, we find that whatever the starting conditions, amazingly you get the same outcome. Every time you pull this particular carbon trigger at a certain rate and dump it into the atmosphere, that’s what you get.

He explains how a common statement from a scientific society composed of “academics and oil men” was forged:

We took the view that although our Society is a mixture of academics and oilmen, and some of us are a mixture — I’m a mixture of those two things myself, we’re a professional body and a learned body – but we thought it was time to make a public statement about things that we agree as a group of geologists are established beyond a reasonable doubt.

And that’s against the background where nobody in their right mind argues that [we haven’t] already dumped several hundred gigatons of carbon into the atmosphere. That’s observational science. .. And we geologists are now saying, right, if you do that, here’s what’s going to happen.

I asked him to describe the source of the strength in a geological approach to weighing the causes and consequences of changes in the climate:

This is based on lots of different people going back and examining the same pieces of rock. We have this big advantage that we can’t argue with the rock. We argue with each other. But if we can’t resolve the argument we go back to the piece of rock again and then work out the answer. And the answer every time appears to be, if you do this, if you keep on doing what we’re doing now, we will repeat, in all essential details, the past warming event — at which stage geologists can take a really lofty view – which unless you’ve got grandchildren you tend to do – and you say, well, we don’t care. The Earth will survive. It survived all these past events. I found my own experience was not only the November, 1999, article in Nature [“Carbon cycling and chronology of climate warming during the Palaeocene/Eocene transition,” Norris and Röhl] but the arrival of the grandchildren, you tend to think this is a pretty bad legacy because we are now quite confident that it’s unwise to go on doing what we’re doing. We’re not putting it stronger than that.

We’re not trying to set out the climatological arguments. We’re not judging the merits or demerits of those. We’re saying here’s an independent line of argument. And I’d have to say that if I have to save my life by winning an argument with oil men in a bar in Midland, Tex., on this topic, I would go in with some lumps of black mudstone from the ancient rock record, I’d go in with the established figures on our present input of carbon dioxide, and I’d say which bit of this observational science do you guys quarrel with, and why?

I then asked him to muse on the focus of that London conference – the notion that human activity has reached a scale that, for a time, at least, will dominate other conditions shaping the formation of striated rocks, the most basic timekeeping system of the Earth. His response, was of course, centered on the rocks that end up recording much of what transpires on this planet:

I would like us to behave around the planet now in a way that makes it very tough to spot the Anthropocene in the future geological record.

 

Read the full article and follow-up on the New York Times dotEarth blog.