Carbon Capture Could Be Key

If you've paid any attention to the green movement, you'll know that global carbon emissions have far outpaced natural levels, and that numerous efforts are underway to reduce emissions and the climate change they will cause.

But in spite of these efforts, “we are not on track to reduce global climate emissions,” Thomas Halsey of ExxonMobil Upstream Research said during a public lecture Wednesday. Renewable energy, improved transportation and energy efficiency have the potential to greatly reduce global emissions, but not to the degree that is necessary. If this is true, how do we fill the gap? One major factor will be carbon capture and storage - preventing carbon emissions from entering the atmosphere and causing warming.

“A lot of the carbon dioxide in the atmosphere comes from relatively concentrated sources,” e.g. power plants rather than car tailpipes, Halsey said.

A few technologies exist for capturing carbon at power plants, with varying costs and efficiency. Post-combustion CO2 filtration is commercially available already. Pre-combustion carbon capture separates CO2 and injects only hydrogen as fuel for the turbine. Demonstration plants exist, but are plagued by problems due to the complexity of the technology. Oxy-Fuel combusts pure oxygen, but requires very high temperatures and thus large amounts of energy (somewhat negating the positive benefits).

The one thing all three technologies seem to have in common is their high cost. In countries that have a carbon tax, like Norway, carbon capture is more feasible. But in the United States, adoption of the technology is slow-going.

And carbon capture is just one part of the equation. Once extracted, where could the CO2 be put to prevent it from entering the atmosphere? Enhanced Oilfield Recovery (EOR) is one possibility for use; when CO2 is injected into oil or gas reservoirs, it increases rates of recovery. EOR has been practiced for many years and is already in use at more than 100 oil fields, although many more could potentially benefit.

Carbon sequestration, the traditional option, involves injecting captured CO2 into the earth, into either unmine-able coal beds, deep saline aquifers or depleted oil/gas reserves. Geological barriers prevent the gas from returning to the surface.

Techonology	Pros	Cons
Oil/Gas Reservoirs	Increased recovery	Scale and capacity Other people have drilled wells; might not know where they all are
Saline Aquifers	Large scale, distribution and capacity	Lack of research
Unmine-able Coal Beds	Increase coal bed methane production	Injectivity problems (coal swells with CO2 injection and blocks pathways); Pilot programs didn't work

Pros and cons must be carefully considered because “we don’t want to put the CO2 down and have it come back up,” Halsey said.

The Sleipner oil field in the North Sea, in use since 1998, has successfully injected 10 million tons of CO2 into an underground reservoir. Constant monitoring has shown some upward CO2 migration, but there is no evidence for leakage through the overlying shale barrier. The potential for earthquake activity is troublesome, but it is “a standard oil industry technical problem,” according to Halsey.

The monitoring required for such projects bring up an interesting issue-- who will be responsible for long-term storage stewardship? Companies would not be willing to invest if saddled with liability for hundreds of years. At some point, liability would need to be transferred to the public sector. Many issues exist, but if they are overcome, CCS could be a crucial tool for reducing catastrophic climate change.

How Do Rodents Make Decisions? A Nobel Laureate Speaks

Ion channels, the small tunnels that allow charged particles to flow through the cell membrane, play a significant role in various physiological functions. For neurobiologists, measuring the electric current associated with these ion channels proved to be a hard task, as a vast amount of information was lost due to noise.

The technique that was developed to overcome the loss of electric signals is called the patch clamp, and is one of the most widely used tools to study physiological processes on a molecular level today. One of the co-developers of this technique and a Nobel laureate, Dr. Bert Sakmann, was here on Friday to talk about his research at a seminar organized by the Duke Institute for Brain Sciences.

'We studied the neural connections in rodents using the Whisker model", Sakmann said to a packed auditorium.

The Whisker model was a whisker-dependent learning task in which the rodents had to make the decision whether to cross a small gap or not. "We wanted to know how many (neuronal) columns (of the brain were) involved in the decision-making process."

Through these experiments, Dr. Sakmann and fellow Nobel Laureate Dr. Erwin Neher identified certain cortical circuits that were activated during this decision-making process. "We measured the latency between stimulus and activation, and found there is a very precise and small latency."

They further discovered that decision-making is possible using a single column in the cortex. To measure the electric current associated within such single cells, they developed the patch clamp technique.

The patch clamp enabled the study of single ion channels and helped gain insight into the role of these channels in hormone regulation, heart diseases, epilepsy, and diabetes among others. A small video demonstrating the technique can be found below.

Sakmann and Neher received the Nobel Prize for Medicine in 1991 for their work.

What Comes After Genetics?

Guest post from James Todd, host of Duke's online "Office Hours" program.

Just when you thought you had a grip on genetics and genomics, there's this new thing called "epigenetics” that is becoming increasingly prominent.

One of the pioneers of this new field is Duke's Randy Jirtle. (visit his lab’s website)

Two years ago, the National Institutes of Health announced that it planned to provided $190 million in funding for epigenetics research over five years, as part of its Roadmap Epigenomics Program. Recent stories by NOVA, Time and the Washington Post have highlighted the importance of the field.

So what is epigenetics? Jirtle gives a definition in this video.

Curious to learn more? You can also watch Jirtle’s recent “Office Hours” interview.

Biomedically Enhancing Humanity

Human enhancement has many forms: medication, caffeine, braces, contact lenses, steroids... but also education and science -- a collective intellectual enhancement. According to philosophy and public policy professor Allen Buchanan, “human beings have been enhancing themselves as long as they have been humans.”

Buchanan kicked off the 2010 A. B. Duke lecture series last week with his thoughts about the ethics of biomedical enhancement. Biomedical enhancements (BEs) are interventions that act directly on the body, improving some particular capacity. But “getting an enhancement doesn’t necessarily make you better off,” Buchanan noted. For instance, a person might wish to enhance their hearing, but enhancing it too much might make life unpleasant.

BEs can be cognitive or affective (improving mood or moral sentiments), can increase one’s resistance to disease or increase life span and quality of life. Different modes of BE include drugs, tissue/organ replacements, computerized neural implants and germline genetic interventions (genetically engineered embryos or sperm).

According to Buchanan, it’s not true that biomedical enhancements differ from traditional enhancements. For instance, if a person is highly reliant on their computer, then how different would it be to make that computer accessible via their mind?

BE certainly raises some interesting ethical questions, and has some incredible applications. One example is the ability to spread adaptive genes laterally, from person to person rather than from parent to offspring. This could have been helpful when infectious diseases like smallpox and bubonic plague wreacked havoc on human populations. Genetic resistance to a disease was uncommon before an outbreak, but quite prevalent afterwards, as only disease-resistant individuals survived to bear children. These deadly diseases produced rapid genetic change across whole populations, but millions died in the process. Alternatively, intentional genetic modification (IGM) “could spread desirable mutations more quickly and without the human cost,” according to Buchanan.

Opponents are concerned that BE could destroy human nature, have unintended bad consequences and/or provide an unfair advantage if only made available to some. Furthermore, there is the possibility for malicious dual use (repressive social control à la Brave New World).

But according to Buchanan, “It’s not a matter of being for or against it... because it’s going to happen. It’s already here.” Biomedical research frequently produces discoveries relevant to human enhancement. The only way to stop this would be to cease all biomedical research... and that’s just not going to happen.

One common argument against BE is that it interferes with nature. But Buchanan thinks we're giving nature, and evolution, too much credit.

“Don’t think of evolution as a master engineer ... Suboptimal design is a pervasive and necessary feature in evolution.” Buchanan went on to list several less-than-intelligent attributes:

• The dual function of the human pharynx (breathing and swallowing); resultant choking
• Humans’ inability to biosynthesize Vitamin C (We have the genetic pieces for it to be possible, but one part is missing, probably due to a mutation long ago)
• The male urinary tract goes through the prostate, instead of around it, making it prone to infection. The primate sinus is also prone to infection.
• The human birth canal runs through the female pelvis. As humans evolved to walk on two feet, and as human cranium size increased, giving birth became increasingly risky for both mother and child.

“How reliable is evolution as a means for improving human life -- or even for sustaining it?” Buchanan said. “Evolution doesn’t care what happens to you after you reproduce.” This might explain the preponderance of later-life problems, such as cardiovascular degeneration and accumulated mutations that lead to cancer. “There’s no reason to believe that evolution will correct [these problems],” Buchanan said. “In fact, there’s every reason to believe it won’t.”

Buchanan emphasized that humans must look beyond evolution’s haphazard progression. “[Evolutionary success] depends on a fitness between the organism and the environment, and the environment is constantly changing.” Furthermore, “current organisms are not the apex of evolution,” Buchanan said. “We are not completed works. It’s not the end!”