Honeycomb-like nanostructure creates electricity from light


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Zoom in to the nanometer scale—less than the width of a human hair—and you might think the new device designed by a team of scientists led by Lei Zhang is a honeycomb. Upon closer inspection, you would find that the hexagonal structure is made of gold and that a long string of organic molecules winds up and down through each hexagonal space. And one more thing: this device, so perfectly structured in the world of atoms and molecules, can create electricity from light.

These researchers from the Universities of Strasbourg and Nova Gorica have developed a novel structure that could overcome some of the obstacles faced by organic solar cells. As the name implies, these types of solar cells employ an organic molecule that absorbs light to create an excited and negatively charged electron. However, the electron leaves behind a positively charged hole when excited, and these oppositely charged particles need to be separated—electrons going to the cathode, holes to the anode—to generate current, in order for the solar cell to be useful. This separation process, which is very difficult to achieve in organic solar cells, is the focus of extensive scientific research.

One possible solution to this technical obstacle is to use an organic nanowire as a light absorber. The nanowire consists of a long chain of the organic absorbing material stacked one after another. The benefit of such a structure is its high surface-to-volume ratio, which means that electrons and holes spend little time close to one another before reaching the nanowire’s surface and jumping their separate ways to the cathode and anode. This idea has tantalized researchers for some time; however, it has been difficult to create a structure that easily connects the nanowire to the electrodes.

Zhang’s team has found a promising solution through a both practical and artful design. Beginning with a silicon substrate acting as the anode, the researchers patterned a gold honeycomb on top of it to act as the cathode. Finally, the organic nanowire, made of a molecule known as PTCDI-C8, was deposited to snake across the top of the honeycomb, then down along the exposed silicon base, then up along the gold honeycomb, and so forth, like a snake weaving through the hexagons. Such a unique design creates innumerable contacts between the organic wire and the gold (cathode) and silicon (anode), giving plenty of opportunities for the photoexcited electron and hole to separate and zoom away to create an electrical current.

The true beauty of this device may rest in its method of creation. Tiny—in fact, nanoscale—spheres were set onto the silicon substrate in a honeycomb shape to act as a mask, just like using tape to cover parts of a wall you don’t want to paint. Then, gold was deposited over the entire silicon substrate. Finally, the spheres were etched away, leaving a perfect honeycomb gold electrode. This entire process creates a large enough honeycomb mesh to allow for hundreds of organic nanowires to lace through it.

Using this new nanowire device, half of all photoexcited electrons and holes could escape to the electrodes to contribute to the electrical current: a very good number for organic solar cells. In addition, Zhang and his team hope to use the device to test the fundamental properties of one-dimensional organic materials by varying the electrode size and measuring changes in performance. The device could also be used as a photodetector, and its design could be a template for light-emitting diodes. Above all, the finely tuned structure marks another significant advance in scientists’ ability to control the patterns of nature at the levels of atoms and molecules.


Slim, S. and Rosel, F. “Asymmetry in supramolecular assembly.” Science, 353(6304), 1098-9, 2016.

Zhang, L. et al. “A nanomesh scaffold for supramolecular nanowire optoelectronic devices.” Nature Nanotechnology, published online 25 July 2016.

Image credit: Merdal via Wikimedia Commons.

Note: All views expressed are solely his own and do not reflect those of his employer.

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Chilean solar farm will be cheapest power project ever

Courtesy of blickpixel via Pixabay

Courtesy of blickpixel via Pixabay

Chilean President, Michelle Bachelet, has been looking for some sort of magic for a long time to ignite her country’s sluggish economy.  The spell may finally be cast in the form of solar energy.

Bloomberg reports that a host of electricity supply contracts have been auctioned off that decrease the average price for customers by 40 percent compared to last year.  Among these contracts is one deal with Solarpack Corp. Tecnologica to sell power from a 120-Megawatt (MW) solar farm for only 29.1 dollars per MW-hour.  That corresponds to 2.91 cents per kW-hour, less than the previous record of 2.99 cents per kW-hour for a Dubai project!  Many of the other contracts also involve renewable energy projects.


Experts are hopeful this is just the beginning.  A renewed emphasis on machinery investment has helped to create this energy boom.  “Many of these investments are projects that will have to be built,” Bachelt said.  “We are talking about $3 billion in investment that will generate 3000 new jobs, so this is good news for the economy.”

Good news for the economy as well as the environment.  This 2.91 cents per kW-hour contracted price is completely unsubsidized, an incredibly hopeful sign that solar can compete in certain climates now.  Chile has natural advantages to be a world leader in this regard, with some of the world’s highest solar radiation that makes solar panels more efficient.

It should also be noted that this low price for solar is contracted for 2021, when the plant construction is expected to be completed.  Therefore, the low price is agreed upon based on expected improvements in technology, like inverters, that will continue to reduce manufacturing costs between now and then.  Therefore, we shouldn’t necessarily interpret this price as where solar is now, but rather where it is clearly heading in the near future.  Still great news for solar!


Sanders, P. “Chile energy auction gives Bachelet a success to boast about.” Bloomberg Markets, accessed August 29, 2016.

Romm, J. “Solar delivers cheapest electricity ‘ever, anywhere, by any technology.’ ” Think Progress, accessed August 29, 2016.

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Ebbs and Floes: Watching the Arctic Ice Melt


A large pool of melt water over sea ice, as seen from an Operation IceBridge flight over the Beaufort Sea on July 14, 2016. During this summer campaign, IceBridge will map the extent, frequency and depth of melt ponds like these to help scientists forecast the Arctic sea ice yearly minimum extent in September.

It’s my pleasure to introduce a guest post by Norman Rusin!  Norman is a freelance journalist and copy editor who helps writers produce sound and telling communications. He is about to complete his doctoral dissertation in Italian Studies at the University of Pennsylvania. In his research he looks at how science, literature, and art complement each other. Connect with him at @normanrusin.

This article was originally published by GotScience.org, which translates complex research findings into accessible insights on science, nature, and technology. Help keep GotScience free! Donate or visit our gift shop. For more science news subscribe to our weekly digest.


Last July, a team of NASA scientists succeeded in collecting data about summer melting ice in the Arctic during a first-of-its-kind operation. The team surveyed the Arctic Ocean off the Alaskan coast, in Barrow, to measure the aquamarine pools of meltwater on floes—huge chunks of floating ice—that may be accelerating the overall sea ice retreat.

They chose the northernmost US city because of its proximity to the ocean. However, they knew they would face unstable weather conditions there, so they would have to pursue targets of opportunity. The day before each flight they studied weather imagery and models and tried to plan a flight line that “basically gets into any hole in the clouds there is, rather than following a specific path,” explained Nathan Kurtz, IceBridge’s project scientist and a sea ice researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Why Measure Melt Ponds?

After a record-warm winter in the Arctic, and with sea ice across the Arctic Ocean shrinking to below-average levels, the researchers decided to launch Operation IceBridge to map the extent, frequency, and depth of melt ponds, the pools of meltwater that form on sea ice during spring and summer. In fact, recent studies have found that the formation of melt ponds early in the warm season is a good predictor of the sea ice yearly minimum extent in September. If there are more ponds on the ice earlier in the melt season, they reduce the ability of sea ice to reflect solar radiation, which leads to more melt.

The operation is the first of its kind; there has never been such an extensive study of this phenomenon. “Although there have been previous airborne campaigns in the Arctic, no one has ever mapped the large-scale depth of melt ponds on sea ice using remote sensing data,” said Kurtz. “The information we’ll collect is going to show how much water is retained in melt ponds and what kind of topography is needed on the sea ice to constrain them, which will help improve melt pond models.”

The Flights

On the first flight, the team took off in the fog and had to fly for a couple of hundred miles before the clouds cleared up. Moreover, their airplane, an HU-25C Guardian Falcon, had a smaller fuel capacity compared to the P-3 aircraft that NASA has used in the Arctic so far. This time, they had to fly for a shorter time than the usual Arctic flights. So they planned several four-hour flights, at an altitude of 1,500 feet (450 meters), each one covering 1,000 nautical miles (1,150 miles) and focusing on the Beaufort and Chukchi seas north of Russia, Alaska, and Canada.

On the plane the researchers carried three instruments: a laser altimeter that measures the heights of the water, snow, and ice; an infrared imager that provides temperature readings to help differentiate between water and ice; and a downward-facing mapping camera. They studied how well the laser altimeter measures the depth of melt ponds, which is another possible indication of the year’s overall melt season. Kurtz and his colleagues investigated whether a combination of measurements can help estimate sea ice thickness—a tricky piece of information to get, but one that could provide clues to how fast the summer ice will melt, or whether it could stick around for another year.

The Different Face of Summer Ice

When you think about polar ice, you might picture a never-ending, white, flat surface. This is not its condition in the summer, though. “Now, in the summer, it’s just so variable,” Kurtz said. “You see places where the floes are a lot more broken up; you see a mixture of places where the snow has melted, and you see bare ice, and various depths of melt ponds … you see these patches all over of ice in different stages of melt.”

While scanning floes cracked into pieces and blotched with ponds of melted water, Kurtz noted different shades of white—signs of ice or snow on top of the ice—and brown, maybe due to embedded algae. Colors reveal the ice depth: the deeper the blue of the pond, the thicker the ice where the melting occurred. Most ponds, then, connect to each other with circling black rivers that flow into the open sea.

Kurtz and his team measured changes in the ice elevation and surface temperatures and created color maps of sea ice. Eventually, they will correlate the measurements of polar ice with two other NASA satellite campaigns: the Ice, Cloud and Land Elevation Satellite, or ICESat, which operated from 2003 to 2009, and its successor, ICESat-2, scheduled to launch by 2018. The Barrow expedition gave a glimpse into what ICESat-2 will be able to observe in the Arctic in the summertime, since the laser altimeter IceBridge carried is similar to the one that will be aboard ICESat-2. Overall, these measurements will improve studies of sea ice thickness in the Arctic and will give us a better sense of the extent and pace of climate change.



Figure of large pool of melt water over sea ice courtesy of NASA/Operation IceBridge.

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Sunlight: the equitable energy source

Solar energy is touted for a variety of reasons – it’s renewable, clean, quiet, and can be used as a decentralized form of electricity generation.  But I came across a figure while doing some reading that reveals a less-discussed benefit of using solar energy that may be most important (depending on your priorities when it comes to global issues).

Below is the figure, reproduced from a recent 2015 paper in Energy and Environmental Science that reviewed all that we know about the solar resource and the technology we’ve created to harness it.  I’ll show it first and then discuss its important details.


There’s a lot going on here, so let’s break it down.  The top left image (a) shows the irradiance, or power per square meter (W/m2), as a function of geography.  This tells us just how much solar energy is hitting the surface over a given time and area.  As would be expected, the most solar power arrives closer to the Equator, with the largest amounts of available power located in the US Southwest, Sahara, central Asia, and Australia.

However, the intriguing benefits of solar energy are revealed when we look at averaging this available power across longitudes or latitudes.  Figures (b), (c), and (d) plot land area, population, and irradiance as a function of longitude, averaged across latitude.  Notice how solar power is consistently available across all longitudes (Figure (d))!  To a certain limit, it doesn’t matter where you live in the Eastern or Western hemisphere – solar power will be available to you.

Figures (e), (f), and (g) similarly plot land, population, and available solar power as a function of latitude, averaged across longitudes.  Here, we see a slightly different but still beneficial pattern.  Clearly, less solar power is available near the Arctic and Antarctic poles (Figure (g)), but the level of irradiance still generally correlates with the largest population densities, particularly near the 30 degrees N latitude line (compare (f) and (g)).

So, on average, people across the globe live close to available solar power.  That’s a good start, but there’s more!  Figure (h) plots the GDP per capita of countries in 2011 against the amount of the solar energy hitting that country per square meter per day (known as insolation).  This type of scatter plot is a great tool for visualizing correlations between two variables.  If GDP per capita and insolation were positively correlated, for example, then we would see richer countries have much higher levels of insolation than poorer countries.  Fortunately, that’s not the case!  Instead, almost no correlation exists between these two variables, indicating that all countries have a similar potential to harness solar energy to power their homes, businesses, and communities.

Consider the implications.  Across geography and wealth, no country lacks direct access to sunlight as an energy source.  The same cannot be said of coal, oil, or natural gas, all of which require extraction of resources from geographically specific locations.  Developing countries with less GDP per capita even have a slightly larger solar resource, on average, indicating the potential to use capital investment and infrastructure in the solar industry to spur growth in these countries.

Of course, developing countries can do little with the available solar energy if their governments or policies are not equipped to take advantage.  But no extractive energy resource boasts these benefits of geographic and economic equality.  Just another reason to support the advancement of solar technology and economic development plans that encourage its distribution!


Figure courtesy of Jean J et al. “Pathways for photovoltaics.” Energy Environ Sci8, 1200, 2015.

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The Presidential Promise of a Half-Billion Solar Cells

Figure courtesy of Walmart via Flickr

Figure courtesy of Walmart via Flickr

It is my pleasure to introduce Adam Kirk as guest writer for this week’s post!  Adam is a freelance writer specializing in renewable energy and associated topics.  To find out more or hire Adam for your own website, visit AdamKirkWriter.com.

Last week, Hillary Clinton secured the nomination of the Democratic party for this year’s presidential election.  The stark contrast between the environmental positions of the Democratic and Republican platforms are being highlighted more so than other recent presidential campaigns.  With the election coming so soon after the Paris Agreement on climate change and off the back of Obama’s own Clean Power Plan, there is voter value in the pledges made by candidates with respect to the environment.

Large  divisions between Donald Trump’s and Hillary Clinton’s views on global warming provide a sharp contrast for voters making decisions based on environmental concerns. Trump has been quoted in the past year stating that “green energy is just an expensive feel-good for tree-huggers” and that “I’m not a big believer in man-made climate change.” These statements would seem to echo the view of many in his party, including most of the original presidential candidate contenders.

On the other side, Hillary Clinton has been very vocal in her belief that more effective action needs to be taken by the US, declaring that “we do not have to choose between a healthy environment and a healthy economy”, but not before handling potential challenges from her past role in the Obama administration.  Indeed, she clearly admits to the United States’ role in global warming, stating that “we acknowledge – now with President Obama – that we have made mistakes in the United States, and we along with other developed countries have contributed most significantly to the problem we face with climate change”.

Based on these positions, the ‘pro-environment’ candidate is Hillary Clinton. What, exactly, is she planning to do to deliver on the rhetoric? The answer, as you will see shortly, is certainly ambitious.  The question is: can she deliver?

Hillary Clinton: Leading on Environmental Change?

Hillary Clinton and the Democrats sit firmly on the side wanting to fight climate change. As evidence, she has laid out a challenging plan and committed to implement it on ‘day one’.  In July 2015, Hillary Clinton and her campaign team set out her commitments on the environment in this briefing document. In essence, it contains two key commitments:

  1. By 2020 (i.e. the end of her first term as president) the USA will have half a billion solar panels installed.
  2. Within 10 years of her taking office (2027) the USA will generate enough clean, renewable energy to power every home in America.

Let’s examine each of these goals and understand how she plans to achieve such an ambitious proposal.

1) A Half-Billion Solar Panels by 2020

500,000,000 solar panels is a huge number and it helps to put some context around it.

The Topaz Solar Farm in southern California is the fourth largest PV power station in the world with 9 million solar panels generating 550MW.

Those nine million panels are just 1.8% of Hillary Clinton’s target; she’ll need to establish 55 Topaz’s to reach her 2020 goal.

Fortunately, she’s not starting from nothing.   The USA already has three of the largest five PV power stations in the world (China and India have the largest two) and over half the largest 20.  Talking about them in terms of solar panel count may be great for attracting votes, but it is not helpful when considering energy production.  For example, the USA’s largest PV power plant is Solar Star, also in southern California. It generates 579 MW to Topaz’s 550 MW, but only uses 1.9m panels to achieve it – less than a quarter of Topaz’s count.

This is an important distinction because it is the efficiency of the panels used which will be just as important as their number. The best efficiency today of commercially available PV cells is around 20%, but science lab’s have produced crystals with efficiencies as high as 44.4%. It’s easy to see that technology twice as efficient as today’s panels means less land, fewer materials, and lower cost to produce the same amount of energy.

With panel efficiency in mind, instead of using a panel count as a primary goal, the more useful detail under the half-billion pledge is the capacity target of 140 GW by the end of 2020 (although there’s no mention of the assumptions underpinning the link between a half billion panels and 140 GW, the math suggests if the calculation assumed the efficiency of Solar Star’s panels Clinton would need around 460 million of them to produce 140 GW).  At the end of 2015, America had 25 GW of PV power capability with 30 GW of additional capacity planned. There’s an additional 6 GW in distributed generation from residential and non-residential premises, summing to give 61 GW of power available/planned when Clinton takes office.

At 140 GW, the Clinton solar commitment would require doubling that capacity over the next four years, which might appear unfeasible. However,  recent growth in solar energy is booming. This chart shows growth solar-produced energy was sluggish in the US until 2011, before hitting ‘hockey stick’ exponential growth. Between 2013 and 2014, production levels doubled. Not only that, according to the US Department of Energy, the number of homes using solar energy increased 10-fold from 2006 to 2013, and is expected to increase another 2 – 10 times before Clinton’s 2020 deadline. It almost feels like a hard target to miss.

2) Enough Clean, Renewable Energy to Power Every Home in America

This eye-catching statement is another great one for voters but its wording could be misleading.  The target could be every home will be powered by clean energy, or the US will produce enough energy that the total energy use of American homes could be met by electricity produced from clean sources in 10 years.

Assuming the latter scenario of an equivalent production, the demands are startling. The amount of energy required to power the equivalent requirement of all the homes in America (125 million in 2015), consuming around 11,000kWh each, is almost 21,000 Trillion British Thermal Units. Just 770 Trillion of those, or 3.7%, were fueled by clean power technologies.

This second pledge seems significantly more challenging to achieve. It needs a 30-fold increase in last year’s production to achieve her 10-year goal and, perhaps more significantly, it increases the Clean Power Plan target of energy coming from renewables by 2027 from 25 to 33 percent.  

It is no surprise in the face of such an ambitious target that the language shifts away from talking solely about solar to ‘clean renewable energy’. Moving the focus makes sense pragmatically, given that wind electricity production in the US is already around three times that of solar.  It also make political sense, since voters in states like Iowa, where almost a third of their power came from wind last year, might feel snubbed with all efforts devoted only to the solar industry.  

According to Energy Information Administration projections, wind energy production capacity could double to around 180 GW in 2027.  Increasing clean energy production to provide 33% of the country’s needs is going to require both a variety of forms of energy production and lots of effective support.

If the goal is for every home to actually provide their own clean power, then wind, solar, geothermal, and biomass production will all need to be in the mix.

How Will the Plan be Achieved and What are the Challenges?

Hillary Clinton’s incentives revolve around a $60 billion mixture of competitions and ‘prizes’ to motivate states and communities to beat already-established targets, plus federal support to remove barriers for low-income families to install solar panels.

There are a number of obstacles she will have to face, not least of these being Republicans that are likely to retain power in the House of Representatives. If this occurs, her own campaign chair, John Podesta, recognises that Clinton’s hands will be tied when it comes to comprehensive energy policy change.  It seems her way of dealing with a Republican House is to work around it, which she appears happy to do.

The rest of her team appears to support the same tactic. In an interview with GreenTech Media earlier this year, Trevor Houser (Hillary Clinton’s energy policy advisor) explains she’ll work around Congress by using existing authorities, partnerships with states, and direct federal investments.

Aside from the Republicans, she has two other challenges to consider.  The first is the Keystone XL oil sands pipeline from Canada that is proposed to travel the length of the US. This project has become an anchor for a philosophical argument between the two sides of the environmental debate (how that happened is brilliantly explained in this New York Times video). The pipeline causes Clinton headaches for two reasons: the first is that she was Secretary of State when it was originally discussed – she has ‘skin in the game’ – and the second is that Obama is the person who has to authorise it coming over the border.  Being on his ‘side’, Clinton is constantly forced to decline sharing her view on whether she’d allow it or not so as not to undermine his position, possibly hurting her own environmental credentials.

Her second challenge of note is one which, depending on your perspective, could be characterised as being naive or dishonest.  There is significant opinion that Hillary’s plans for delivering the change she is pledging will only get us part of the way there and that the only mechanism that will really move the dial is putting a value (or tax) on carbon. Discussions of new taxes could be toxic for voters and a gift for Trump, so Clinton has made no mention of it to date, but perhaps she should take solace from this poll which suggests even a slight majority of republicans would be supportive of a carbon tax if it was managed in the right way (i.e., used for R&D in renewable energy or as a fee and dividend returned to the public).

What is Next for Hillary’s Plan?

Whatever your view, it is hard to argue that the objectives are not ambitious or for the good of the environment, although there are a lot of gaps still to be plugged.  

Clinton is pledging two significant environmental policy targets that will be set on her first day in office. The first goal of a half-billion solar panels is definitely lofty, but she would inherit 1) a momentum of growth in the industry , 2) a growing conviction that human-made climate change needs to be tackled proactively, and 3) technology that’s edging ever closer to higher efficiency (and so relatively cheaper) panels. In all, this feels very achievable.

The second target is substantially more ambitious. Hillary Clinton is setting out on a ten-year journey to increase the amount of sustainable energy produced in the US to 33% from today’s 3%. The incentive program to do this is large, but it faces substantial challenges from a Republican house and, as yet, no mention of what role taxes will play in achieving it. This is definitely the harder target to be positive about and, cynically, perhaps that’s why it’s only deliverable by a different president, even if Hillary achieves two terms in office.

As President Obama has discovered over the course of his eight-year journey, there is only so much even the West’s most powerful leader can achieve when political views are so polarised.  Even though she may have “put the biggest crack in that glass ceiling yet”, Hillary still has to wake up victorious on November 9th for her bold environmental plan to stand any chance at all.


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Carbon capture: transforming greenhouse gas into rock


This article was originally published by GotScience.org, which translates complex research findings into accessible insights on science, nature, and technology. Help keep GotScience free! Donate or visit our gift shop. For more science news subscribe to our weekly digest.

A few months ago, after drilling a well 400 meters deep, scientists in Iceland were repeatedly frustrated that the well kept breaking down. Retrieving the pump from the depths of the earth, they found its base covered in a scaly green and white material that clogged the end of the machine. Instead of feeling dismay over the equipment failure, the scientists celebrated. The crusty residue was calcite, a hopeful sign that the researchers had developed a new method to chemically trap carbon dioxide (CO2) underground and mitigate climate change.

A promise always a decade away

The idea of carbon capture and storage (CCS) has had many advocates and critics. The goal is simple: Find a way to grab all the CO2 emitted during fossil fuel combustion, and permanently sequester it somewhere on the planet, either in geologic formations or the deep ocean, where it cannot escape into the atmosphere. Supporters claim that the technology can create “clean coal,” allowing society to continue to burn away fossil fuels using existing infrastructure. Proponents have carried out a host of pilot projects, the most common using sandstone or depleted oil wells as storage sites, because engineers and scientists already know how these sites operate from the oil and gas business. Unfortunately, no feasible path to cheap and reliable CCS has come from this work.

The problem with current CCS technology is twofold. First, current state-of-the-art technology using old well sites is estimated to cost 50 to 100 dollars per ton of CO2 stored. Imagine that an initial goal of the technology would be to store just 20 percent of the 35.9 Gigatons of global CO2 emissions from 2014. This puts a minimum cost of such CCS at $359 trillion!

Price is not the only concern. Even if CO2 could be affordably stored in sandstone, the molecule’s probability of escape is too high. Rock layers typically cap these storage sites and are sensitive to seismic activity. Fissures in the rocks could allow fluid to leak through and provide the perfect vehicle for CO2 to escape back into the atmosphere. Researchers have not been able to find a storage site that prevents the possibility of this type of leak, making the long-term application of the technology infeasible.

The chemistry of carbon storage

Remember those happy Icelandic scientists? They just may have found a solution. Twenty-five miles east of Reykjavik, a team of scientists from Iceland, the United States, and Europe collected hot, bubbling CO2 from a nearby geothermal plant and injected it 500 meters underground to test a new carbon storage system. The destination: a basalt rock formation.

Why basalt?  Unlike sandstone formations, basalt, an igneous rock, contains many metals, such as calcium, magnesium, or iron, that facilitate a chemical reaction with CO2 known as carbonation. Carbonation transforms the greenhouse gas into calcite, a white and green rock. In contrast to sandstone, which physically constrains CO2underground in a densified gas phase, basalt chemically—and permanently—stores CO2. Fissures and water leaks could no longer allow the greenhouse gas to escape into the atmosphere.

The idea of basalt storage had been considered before, but most computer models suggested that calcite formation would take a decade or even hundreds of years. The scientists in Iceland wanted to try it anyway, at least to gain more information about the chemical process. After doping CO2 from the geothermal plant with heavy carbon to monitor its movement, the scientists plunged 220 tons of CO2 deep into the basalt formation along with a lot of extra water. The addition of water is crucial, because gaseous CO2 by itself could easily escape the injection site before reacting with the metals in the basalt. CO2 is not buoyant and dissolves in water, allowing the chemical reactions to complete before the CO2 degasses.

After the injection, all the scientists could do was watch and wait. Eighteen months after injection, the well broke down, and the elated scientists found the green and white, scaly calcite stuck to the bottom. The chemical reactions necessary for storage took only a little over a year, an order of magnitude less than that predicted by computer models. Over 95 percent of the injected carbon had been transformed into rock.

The speed of the carbonation “means this method could be a viable way to store CO2 underground—permanently and without risk of leakage,” says Juerg Matter, lead author of the study and geologist at the University of Southampton in the United Kingdom.

The difficult path to commercialization

The results from this experiment suggest basalt storage could solve the gas leakage problem intrinsic to most other CCS technologies. Once chemically bonded to form calcite, the CO2 is permanently stored as part of the rock formation. The findings are not specific to Iceland, either. Similar injections into basalt formations have succeeded in Wallula, Washington, and giant basalt formations in the Pacific Northwest make it a perfect location for upscaling the technology.

But challenges remain. More tests are required to confirm that carbonation of injected CO2 is consistently fast and that the Icelandic results were not an anomaly due to particular chemical conditions at the initial test sites. Speed could also be a drawback. If carbonation occurs too quickly, CO2 will not have time to spread throughout the entire basalt formation, limiting storage to locations near the injection site.

Even if these technological issues are addressed, price is still a concern. It is not clear whether basalt storage methods will reduce the price tag currently restraining the market growth of other sequestration technologies. As energy analyst Vaclav Smil has discussed, carbon capture technology requires a tremendous amount of infrastructure. Assuming we want to store just 20 percent of 2010 emissions, Smil estimates this would require transporting 8 billion cubic meters of compressed CO2 gas to storage sites. In comparison, the oil industry transported 4.7 billion cubic meters of crude oil in 2010. This means that carbon sequestration would require “an entirely new worldwide absorption-gathering-compression-transportation-storage industry” that is 70 percent larger than the global crude oil industry developed over multiple decades. Such a challenge would require global cooperation and infrastructure development at an unprecedented pace to prevent CO2from rising above 450 parts per million.

Any new CCS method must be viewed with a hopeful but critical eye. Basalt storage appears to be a technological leap that could lead to its adoption in certain cases, but including carbon sequestration as a major part of any climate mitigation plan will be limited more by politics and global infrastructure than by the viability of any one specific technology.


Matter J.M. et al. “Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions.” Science, 352(6291), 1312-1314, 2016.

Kintisch, E. “New solution to carbon pollution?Science, 352(6291), 1262-1263, 2016.

Smil, V. “Global energy: the latest infatuations.” American Scientist, 99, 212-219, 2011.

Photo Credits

Figure of Nesjavellir Geothermal Power Station courtesy of Gretar Ivarsson

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Australian rodent first mammalian victim of climate change


Tucked away on a small island off the coast of Queensland, Australia, the rat-like animal would have stared up at you with dark, beady eyes from the safety of some scattered shrubs.  No more than 15 centimeters long, the rodent would have been covered with light red fur, its tiny ears tucked tightly against its head, its pale underbelly barely visible.  You would have probably noticed the odd tail, as long as its body and lumpy with scales.

You may have seen this mosaic-tailed rat, melomys rubicola, had you traveled once upon a time to Bramble Cay, a small island built upon a the Great Barrier Reef.  But no longer.  After a fairly exhaustive search using traps, cameras, and searches on foot, Australian scientists have pronounced with confidence that the melomys is likely extinct [1].  The probable cause?  Evidence suggests dramatic weather conditions in the region combined with rising sea levels due to anthropogenic climate change  While a faint glimmer of hope remains that a small colony may still exist on poorly studied region of Papua Guinea, this is likely the first of many mammals to fall victim to the complex weather systems created by global warming.

The future, now

Why should we care?  Some will immediately sense the emotional connection: those cute little eyes and ears a victim of shameless human expansion across the globe.  And I don’t believe this sentiment can be overstated in these times, when we are moving farther and farther away from understanding our connection to the environment the effects of our industry on it.

But there is more to this loss than dealing with accomplice’s guilt.  The present weather systems bombarding Bramble Cay and their effects on the local ecosystem play out our future in fast-forward.  The island rests only 3 or 4 meters above sea level, leaving it susceptible to any slight changes in climate.  Whereas global sea levels have risen 20 centimeters over the last century, the oceans have risen at twice the average rate near Bramble Cay.  As a result, the area of the island consistently above high tide has shrunk since 1998 from 9.8 to 6.2 acres, eliminating the spread of vegetation, low-lying rock overhangs, and 97% of available habitat for the melomys.

As a group of scientists from the Department of Environment and Heritage Protection and the University of Queensland thoroughly documented the island, they found flattened, dead sedge along the coastlines, erosion, and the loss of soft substrate along rock formations.  All these signs point to dramatic weather systems recently hitting the cay.  In 2005, Tropical Cyclone Ingrid blasted the island, destroying up to half of all vegetation by 2011.  Harsh winters during the same time also brought more severe storms through the area.  Increased cyclonic activity near Queensland has already been associated with intensity in the La Nina cycle, which occurs with higher global mean sea surface temperatures due to anthropogenic global warming.  The melomys didn’t stand a chance given the loss of the vegetation and habitat.

“The key factor responsible for the extirpation of this population was almost certainly ocean inundation of the low-lying cay, very likely on multiple occasions, during the last decade, causing dramatic habitat loss and perhaps also direct mortality of individuals,” writes Gynther et al [1].  Such an explanation points to resilience, or the lack thereof: as sea levels rise, ecosystems near the coast or on islands cannot survive such severe storms as easily.

Here it is straight: human-induced global warming leads to changes in El Nino/La Nina oscillations leads to more severe storms leads to dramatic punishment to nearby ecosystems.  The melomys was caught in the middle.  All this happened quite quickly due to the low elevation of Bramble Cay, but this is an omen of what is in store for more heavily populated coastal regions as sea levels continue to rise and storms intensify.

Hope in Papua New Guinea

Australian scientists placed 900 small-mammal traps, set up 60 cameras, and combed the island for any sign of the mammal.  Usually these efforts turn up something, so the lack of a sighting indicates extinction.  But there may still be hope.  Some scientists believe the melomys living on Bramble Cay originated from the Fly River delta region of Papua New Guinea just to north, a less explored habitat that could be housing the last remnants of the species.  The scientists have recommended exploration of this area (if funding is available, of course).

The melomys is the first but not the last.  I never knew of this little creature before news of the search for their existence, but now the rodent serves as another reminder that the effects of global warming are happening now.  Scientists believe the finality of extinctions like these can be prevented if more resources are used to identify at-risk regions and relocate wildlife, not to mention reducing greenhouse gas emissions as quickly as possible.  The success of such a mission usually rests with finding enough money from politicians and governments who see the urgency of such pursuits.


Gynther I, Waller N, and Leung LK-P. “Confirmation of the extinction of the Bramble Cay melomys Melomys rubicola on Bramble Cay, Torres Strait: results and conclusions from a comprehensive survey in August-September 2014.” Unpublished report to the Department of Environment and Heritage Protection, Queensland Government, Brisbane, 2016.

Howard BC. “First mammal species goes extinct due to climate change.National Geographic, June 14 2016.

Figure Credits

Figure of Bramble Cay melomys courtesy of Ian Bell via Wikipedia

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