Each week, I devote part of my Sunday to reading.  I tend to accumulate a lot of saved links on Facebook during the week, and I like to try to keep up with what fellow writers are posting here on WordPress.  At the end of my reading day, I like to put up a post to draw my readers’ attention to a few articles I found to be of particular interest.

Here’s what I enjoyed this week:

Curiosity Finds that Mars’ Methane Changes with the Seasons

by Lisa Grossman, Science News

As I’m sure everyone has heard by now, this week NASA set the scientific community on fire once again, with a stunning series of announcements regarding the Curiosity rover on Mars.  While the discovery of organic matter on Mars nabbed a lot of headlines, Lisa Grossman of Science News writes of another discovery, perhaps far more noteworthy in the search for life on the Red Planet.

In 2004, Michael Mumma of NASA’s Goddard Space Flight Center reported the observation of huge methane plumes on Mars.  This was exciting, as not only is methane an organic compound, but it doesn’t last long when exposed to UV radiation (which Mars has in abundance, thanks to its thin atmosphere).  While the find was exciting, the excitement faded when Curiosity landed on the planet in 2012, and initially failed to detect any methane.

Since then, however, Curiosity has indeed detected traces of atmospheric methane.  What’s far more intriguing is that the levels of methane appear to vary with the seasons.  Methane concentrations on Mars appear to be higher in the summer and early autumn, and lower in late autumn and winter.  This may suggest the existence of subsurface pockets of methane, which would be released more rapidly when frozen soils are warmed by the summer sun.  The rover also detected periodic spikes, which could be caused by rocks shifting beneath the surface, triggering a sudden release.

This discovery is intriguing, as it seems to mirror the seasonal release of methane in colder regions of our own planet, and because on our planet methane is primarily produced by lifeforms, either as a waste product or a result of decomposition.  NASA researchers caution that this may well be a purely geological phenomenon.  However, at the very least, it represents another step toward observed proof of life on Mars.

Cost Plunges for Capturing Carbon Dioxide from the Air

by Robert F. Service, Science Magazine

Carbon capture has long been touted as one of the best means by which to address climate change.  By pulling carbon dioxide from the air, we can reduce atomspheric CO2, while also using the captured carbon to produce synthetic hydrocarbons, from low-carbon fuels to plastics.  The process could reduce global warming while allowing us to reuse CO2 molecules indefinitely.  Unfortunately, for some time now such technology has proven cost-prohibitive (up to $600 per ton, by one estimate).  But that may be changing, as Robert F. Service writes for Science.

A recent study published by David Keith, a physicist at Harvard University, suggests the cost of carbon capture may be far lower than previously thought: between $94-232 per ton.  The discrepancy, according to Stanford University climate scientist Chris Field, likely stems from the fact that previous estimates were based on projections.  Keith’s study, on the other hand, is based on real-world data from a pilot facility in British Columbia.  And the results are very promising.

The cost range provided by the study suggests that in the near future, the cost of synthetic fuels produced through carbon capture will fall into a range that would be competitive with fossil fuels.  The overall cost would fall even lower in states like California, which incentivizes low-carbon fuels.  As the carbon capture process recycles atmospheric CO2, the resultant synthetic fuel would qualify as low-carbon, and command a premium price.  The price could potentially lead to a boom in synthetic fuel production, further lowering the price.

While researchers are optimistic, they caution that this technology is no “silver bullet” when it comes to dealing with climate change.  Current projections suggest countries will have to first drop carbon emissions to nearly zero by mid-century, then begin pulling more carbon out of the atmosphere than they emit, to avoid a catastrophic increase in global temperatures before the end of the century.  However, carbon recycling, when combined with increased use of renewable energy and other carbon-negative technologies, could serve as an important piece in solving our climate puzzle.

How Cheese, Wheat and Alcohol Shaped Human Evolution

by Brian Handwerk, Smithsonian.com

In this fascinating article from Smithsonian.com, Brian Handwerk provides insight into how diet has shaped our evolution as a species, and continues to do so today.

While you may not exactly be what you eat, as the old saying goes, dietary trends have played a major role in human evolution according to recent genetic studies.  Take lactose intolerance, for example.  While all mammals possess the necessary enzyme to metabolize lactose (the sugar found in milk) in infancy, upon weaning this enzyme is no longer produced.  But humans are different: roughly a third of humans retain the ability to comfortably digest lactose throughout their lives.  The gene responsible for this ability is especially prevalent in populations originating in colder climates (including Northern Europe) and other regions where raising cattle has long been a practice (including West Africa).  Humans in these regions likely developed the necessary mutation in response to harsh winters or periods of famine; while milk can be consumed by those who are lactose intolerant through fermentation, the resultant product (cheese or yogurt) packs a lighter caloric punch than raw milk.  And while modern humans living in the developed world can deal with lactose intolerance through lactase pills, the ability to digest lactose remains a major survival trait in the developing world.

From celiac disease to even skin color, recent genetic research shows the pivotal role what we eat has played in making us who we are.  It will be interesting to see where the dietary choices we make lead us as our species continues to evolve.

 

Knowledge is power. Take time out to read a bit every day. It’s your window into the world around you. – MK