Kimberly Ayers

Increasing ocean acidity can also affect nutrients like nitrogen.

The breadth of this study  – 18 research institutions and 21 scientists worldwide — and the examination of hundreds of studies stretching so far back into the geologic record makes this conclusion a singularly solid statement about the present trend.

“From everything we know today, it looks like the current rate of carbon dioxide (CO2) emissions” may spell the loss of “organisms we care about — coral reefs, oysters, salmon,” says Bärbel Hönisch, the study’s lead author, who I reached by phone in New York. She’s a paleo-oceanographer at Columbia University’s Lamont-Doherty Earth Observatory. The paper’s being published today in the journal Science.

The danger comes from what happens when CO2 is absorbed by the oceans: CO2 and water create carbonic acid, the stuff that makes soft drinks bubbly. It also makes the oceans more acidic. That acid can dissolve the shells of “keystone” species that are the building blocks for marine life. The world’s oceans are already twice as acidic – a pH drop from 8.2 to 8.1 — as they were at the start of the Industrial Revolution. That’s an acidification rate 10 times faster than anything found in the record over the past 300 million years, according to this new survey.

For her part in the study, USC doctoral candidate Rowan Martindale was looking at the juncture between the Triassic and Jurassic eras, 200 million years ago. It was a cataclysmic time when the earth’s continents were splitting apart, huge strings of volcanoes were erupting, atmospheric CO2 was at one of the highest levels ever and — you guessed it — hardly any evidence of limestone or coral, two things that dissolve in acidic water. It marked one of the five biggest extinction events in the planet’s history. Atmospheric carbon was increasing at the rate of one gigaton – about 2.2 trillion pounds — per year.

Today, atmospheric carbon is increasing at the rate of eight gigatonnes per year — about 17.6 trillion pounds. ‘Something weird was going on in the ocean back then,” Martindale says. “The modern ocean chemistry is changing, and nobody really knows exactly what’s going happen.”

Hönisch says the team cited hundreds of studies — the journal had to put a limit on their end list of 218 items — and looked at many more over the past year-and-a-half. “The strength is that when we compare these different events [in the geologic record], we can see the similarities. We can also see where we need more information.”

Both Honisch and Martindale will tell you the paleo record has its gaps and intriguing questions for further study — exactly how atmospheric warming interacts with ocean acidity, and key ocean sediments they’d love to sample that have disappeared back below the sea floor, for example — but their conclusion is clear: the world’s oceans are acidifying at a rate that has never been seen before.

“Maybe things are not as bad as we think, but we don’t know, says Hönisch. “[And] by the time we do, it may be too late to turn around.”

Kimberly Ayers

And you thought plastic palm trees had no redeeming value...

A cheap plastic that removes carbon dioxide (CO2) from the atmosphere? “Yes,” says a team of chemists at the University of Southern California’s  (USC) Loker Hydrocarbon Research Institute, led by Nobel Prize winner George Olah. Science Now reports on their work with an inexpensive polymer called polyethylenimine or PEI.

But how to maximize its absorption capabilities? Olah’s team dissolved the polymer in a solvent and spread it out, peanut-butter-style, on fumed silica — you know, like the stuff in those desiccant packets in your electronics packaging (“Do not eat,” by the way).  It’s also used as a stabilizer for lipstick and other make-up.

Here are the geeky details from Science Now:

When the researchers tested the new material’s CO₂-grabbing abilities, they found that in humid air—the kind present in most ambient conditions—each gram of the material sopped up an average of 1.72 nanomoles of CO₂. That’s well above the 1.44 nanomoles per gram absorbed by a recent rival made from aminosilica and among the highest levels of CO₂ absorption from air ever tested, the team reported last month in the Journal of the American Chemical Society. Once saturated with CO₂, the PEI-silica combo is easy to regenerate. The CO₂floats away after the polymer is heated to 85°C. Other commonly used solid CO₂ absorbers must be heated to over 800°C to drive off the CO₂.

Team member Surya Prakash says the polymer could also be used to make vast farms of artificial “trees” that could suck CO2 out of the atmosphere, much like real ones do. Prakash and Olah have been trying to stand the carbon paradigm on its ear for the past several years, exploring it as a positive rather than a negative for the planet. “People tend to think of CO2 as a problem rather than a resource,” he explained. “We want to take CO2, and instead of burying it underground, use it as a raw material, and convert it with alternative energy sources back to fuels and feedstocks.”

Stanford University

Stanford researchers Sally Benson and Jean-Christophe Perrin measure the movement of CO2 through rock samples.

Sally Benson and her lab crew have been giving rocks a very hard time.

The energy resources engineering professor has been heating rock to 122 degrees and subjecting it to the pressure of a hundred atmospheres —  the same pressure present at a half-mile or so underground — to see how carbon dioxide would move through the microscopic nooks and crannies.

It’s a key question for energy companies pinning their hopes on “carbon capture and sequestration” (CCS) as way to mitigate the high greenhouse gas emissions from burning fossil fuels. In practical terms, that means intercepting the CO2 and pumping it underground, essentially forever.

For the past five years, the Stanford team has collected beer can-size samples from rock formations all over North America. They then inject CO2 and water into the cores and take a CT scan, watching how it moves into the tiny pores spaces between individual grains of rock.

Authors say this new study offers the most detailed information yet about how the CO2 might behave underground in particular formations of rock. Benson says what surprised the team was how variable the rock was.

“Now we understand that certain portions of the rock have small pores and other portions have big pores,” Benson told me, after her presentation at this week’s meeting of the American Geophysical Union (#AGU11). “And the areas where you have small pores, it’s really difficult to put CO2 into it, so most of the CO2 ends up in the pore spaces that are the biggest.”

So would the carbon cache leak, releasing the CO2 back into the atmosphere? That was the burning question for Benson’s colleague, graduate student Lin Zuo, who studied the relative permeability of water and CO2. The answer is “No.” When the bubbles of gas come out of solution with the water, they plug up the rock formation because of their low permeability.

It’s a burning question outside the lab, as well. Without a successful CCS technology, there may be no way to reconcile the use of fossil fuels with their high emissions of greenhouse gases.

“Today we’re about 80% dependent on fossil fuels — a lot of natural gas, a lot of coal for electricity in particular,” says Benson, who directs Stanford’s Global Climate and Energy Project. “If we want to really quickly reduce those emissions, we need carbon sequestration as another option.”

The next question, says Benson, is, “We study rocks at a very small spacial scale — a cubic millimeter — but in reality these plumes are going to be very, very large — hundreds of square kilometers, so we need to take what we have learned and figure out how we can scale it up.”

NASA

A satellite view of the Mississippi River shows a mosaic of riverbank land-use patterns.

Rivers and streams in the United States are releasing a lot more CO2 into the atmosphere than scientists previously thought, according to a new study by scientists at Yale. In fact, American waterways are discharging the gas into the atmosphere at a rate of 100 million metric tons per year, an amount equal to a car burning 40 billion gallons of gas, researchers say.

The study, conducted by David Butman and Peter Raymond of the Yale School of Forestry and Environmental Studies, looked at water chemistry data from more than 4,000 rivers and streams. The authors say identifying this significant source of CO2 could change the way scientists model the movement of carbon through ecosystems and the atmosphere.

“These rivers breathe a lot of carbon,” said Butman in a press release from the National Science Foundation, one of the study’s funders. “They are a source of carbon dioxide, just like we breathe out carbon dioxide and like smokestacks emit carbon dioxide.”

The study is published in the current issue of Nature Geoscience.