Tag Archives: dioxide

More atmospheric CO2 could reduce cognitive ability, especially in children

New research from the University of Colorado Boulder, the Colorado School of Public Health, and the University of Pennsylvania found that higher levels of atmospheric CO2 in the future could lead to cognitive issues.

Image via Pixabay.

A new study found that higher concentrations of atmospheric CO2 could negatively impact our cognitive abilities — especially among children in the classroom. The findings were presented at this year’s American Geophysical Union’s Fall Meeting.

Heavy breathing

Prior research has shown that higher-than-average levels of CO2 can impair our thinking and lead to cognitive problems. Children in particular and their academic performance can be negatively impacted by this, but, so far, researchers have identified a simple and elegant solution — open the windows and let some fresh air in.

However, what happens when the air outside also shows higher-than-usual CO2 levels? In an effort to find out, the team used a computer model and looked at two scenarios: one in which we successfully reduce the amount of CO2 we emit into the atmosphere, and one in which we don’t (a business-as-usual scenario). They then analyzed what effects each situation would have on a classroom of children.

In the first scenario, they explain that by 2100 students will be exposed to enough CO2 gas that, judging from the results of previous studies, they would experience a 25% decline in cognitive abilities. Under the second scenario, however, they report that students could experience a whopping 50% decline in cognitive ability.

The study doesn’t look at the effects of breathing higher-than-average quantities of CO2 sporadically — it analyzes the effects of doing so on a regular basis. The team explained that their study was the first to gauge this impact, and that the findings — while definitely worrying — still need to be validated by further research. Note that the paper has been submitted for peer-review pending publication but has yet to pass this step.

All in all, however, it’s another stark reminder that we should make an effort to cut CO2 emissions as quickly as humanly possible. Not only because they’re ‘killing the planet’, but because they will have a deeply negative impact on our quality of life, and mental capacity, in the future.

A preprint of the paper “Fossil fuel combustion is driving indoor CO2 toward levels harmful to human cognition” is available on EarthArXiv, and has been submitted for peer-review and publication in the journal GeoHealth.

Roots.

Research is getting to the root of climate change with bigger, deeper plant roots

New research is trying to give plants stronger, deeper roots to make them scrub more CO2 out of the atmosphere.

Roots.

Image via Pixabay.

Researchers at the Salk Institute are investigating the molecular mechanisms that govern root growth pattern in plants. Their research aims to patch a big hole in our knowledge — while we understand how plant roots develop, we still have no idea which biochemical mechanisms guide the process and how. The team, however, reports to finding a gene that determines whether roots grow deep or shallow in the soil and plans to use it to mitigate climate warming.

Deep roots are not reached by the scorch

“We are incredibly excited about this first discovery on the road to realizing the goals of the Harnessing Plants Initiative,” says Associate Professor Wolfgang Busch, senior author on the paper and a member of Salk’s Plant Molecular and Cellular Biology Laboratory and its Integrative Biology Laboratory.

“Reducing atmospheric CO2 levels is one of the great challenges of our time, and it is personally very meaningful to me to be working toward a solution.”

The study came about as part of Salk’s Harnessing Plants Initiative, which aims to grow plants with deeper and more robust roots. These roots, they hope, will store increased amounts of carbon underground for longer periods of time while helping to meaningfully reduce CO2 in the atmosphere.

The researchers used thale cress (Arabidopsis thaliana) as a model plant, working to identify the genes (and gene variants) that regulate auxin. Auxin is a key plant hormone that has been linked to nearly every aspect of plant growth, but its exact effect on the growth patterns of root systems remained unclear. That’s exactly what the team wanted to find out.

“In order to better view the root growth, I developed and optimized a novel method for studying plant root systems in soil,” says first author Takehiko Ogura, a postdoctoral fellow in the Busch lab. “The roots of A. thaliana are incredibly small so they are not easily visible, but by slicing the plant in half we could better observe and measure the root distributions in the soil.”

One gene called EXOCYST70A3, the team reports, seems to be directly responsible for the development of root system architecture. EXOCYST70A3, they explain, controls the plant’s auxin pathways but doesn’t interfere with other pathways because it acts on a protein PIN4, which mediates the transport of auxin. When the team chemically altered the EXOCYST70A3 gene, the plant’s root system shifted orientation and grew deeper into the soil.

“Biological systems are incredibly complex, so it can be difficult to connect plants’ molecular mechanisms to an environmental response,” says Ogura. “By linking how this gene influences root behavior, we have revealed an important step in how plants adapt to changing environments through the auxin pathway.”

“We hope to use this knowledge of the auxin pathway as a way to uncover more components that are related to these genes and their effect on root system architecture,” adds Busch. “This will help us create better, more adaptable crop plants, such as soybean and corn, that farmers can grow to produce more food for a growing world population.”

In addition to helping plants scrub CO2 out of the atmosphere, the team hopes that these findings can help other researchers understand how plants adapt to differences between seasons, such as various levels of rainfall. This could also point to new ways to tailor plants to better suit today’s warming, changing climate.

The paper “Root System Depth in Arabidopsis Is Shaped by EXOCYST70A3 via the Dynamic Modulation of Auxin Transport” has been published in the journal Cell.

CO2 sticker.

May 2019 sets new record for highest average atmospheric CO2 levels in history

This month set a record for the highest average CO2 concentration in the atmosphere. Yes, a new one.

CO2 sticker.

Image credits Gerd Altmann.

Atmospheric CO2 levels have continued to rise throughout 2019, shows data published by the NOAA and Scripps Institution of Oceanography earlier today. This May, those levels averaged 414.7 parts per million (ppm) as recorded at NOAA’s Mauna Loa Atmospheric Baseline Observatory.

This value is the highest seasonal peak recorded over 61 years of observations at the Mauna Loa Observatory. The highest in 61 years because that’s how long the observatory has been up and running. It’s also the seventh consecutive year of increases in atmospheric levels of CO2 — and it’s also the highest average concentration recorded this year, which already broke a record. The value of 414.7 ppm CO2 is 3.5 ppm higher than the peak recorded in May 2018, and just shy of the 415 ppm peak value recorded in May 2019. Researchers at NOAA report that this increase is the second-highest annual jump on record.

“It’s critically important to have these accurate, long-term measurements of CO2 in order to understand how quickly fossil fuel pollution is changing our climate,” said Pieter Tans, senior scientist with NOAA’s Global Monitoring Division.

“These are measurements of the real atmosphere. They do not depend on any models, but they help us verify climate model projections, which if anything, have underestimated the rapid pace of climate change being observed.”

While still lower than the peak value, the number is still very worrying. It’s worrying because, while fluctuations can lead to high-value but transient peaks in CO2, average concentration readings show the larger trend: and that trend is that levels of CO2 in the atmosphere keep increasing year after year, and that the rate of increase is accelerating.

Some of the earliest recordings at Mauna Loa found annual increases of 0.7 ppm on average per year. This rate increased to about 1.6 ppm per year during the 1980s and 1.5 ppm per year in the 1990s. During the last decade, we’ve seen an average growth rate of atmospheric CO2 concentrations of 2.2 ppm. And, according to Tans (and pretty much every scientist out there), there is no doubt that this rate is increasing because we’re generating more and more emissions.

Monthly average readings are recorded during May of each year, just before plants start to suck up large quantities of CO2 from the atmosphere during the northern hemisphere growing season. In the northern fall, winter, and early spring, plants and soils give off CO2, which cause levels to rise through May. Charles Keeling was the first to observe this seasonal rise and subsequent fall in CO2 levels embedded within annual increases, a cycle now known as the Keeling Curve.

It’s important to take these measurements at the same time each year so as to control as many variables as possible, making the data useful for establishing reliable trends. The Mauna Loa data, together with measurements from other sampling stations around the world, are collected by NOAA’s Global Greenhouse Gas Reference Network and produce a foundational research dataset for international climate science.

NOAA’s report can be accessed here.

Methane.

One research team proposes swapping atmospheric methane for CO2, and it might be a good idea

A relatively simple but counterintuitive approach aims to fight climate change — by actually increasing CO2 emissions.

Methane.

Image via Pixabay.

Fighting climate warming with greenhouse emissions might sound like it won’t work, because it wouldn’t. The team that authored this study, however, doesn’t just aim to increase CO2 levels in the atmosphere. Rather, it proposes that we degrade methane, a much more potent greenhouse gas, into CO2 — the swap, they write, would be a net benefit for world climate.

The study proposes zeolite, a crystalline material that consists primarily of aluminum, silicon, and oxygen, as a key material to help us scrub methane emissions.

The lesser of two evils

“If perfected, this technology could return the atmosphere to pre-industrial concentrations of methane and other gases,” said lead author Rob Jackson, the Michelle and Kevin Douglas Provostial Professor in Earth System Science in Stanford’s School of Earth, Energy & Environmental Sciences.

Much more relevant to the current situation, the team notes, is that this process is also profitable. Boiled down, the idea is to take methane from sources where it’s difficult or expensive to eliminate — from cattle farms or rice paddies, for example — and degrade it into CO2.

Methane concentrations in the atmosphere are almost two-and-a-half times higher today than before the Industrial Revolution, the team explains. There’s a lot less methane than CO2 in the air, granted, but methane is 84 times more potent than CO2 as a climate-warming gas over the first 20 years after its release. Finally, some 60% of atmospheric methane today is directly generated by human activity.

Most climate strategies today focus on CO2, which is understandable. It’s the largest (by quantity) greenhouse gas we emit, and it’s easy to relate to — we breathe out CO2, cars belch out CO2, factories do too, and plants like to munch on it. But scrubbing other greenhouse gases, particularly methane due to its enormous greenhouse effect, could be useful as a complementary approach, the team explains. Furthermore, there’s just so much CO2 already floating around — and we keep pumping it out with such gusto — that CO2-removal scenarios often call for billions of tons to be removed, over decades, which would still not get us to pre-industrial levels

“An alternative is to offset these emissions via methane removal, so there is no net effect on warming the atmosphere,” said study coauthor Chris Field, the Perry L. McCarty Director of the Stanford Woods Institute for the Environment.

Methane levels could be brought back down to pre-industrial levels by removing about 3.2 billion tons of the gas from the atmosphere, the team notes. Converting all of it into CO2 would be equivalent to a few months of global industrial emissions, which is relatively little, but would have an outsized effect: it would eliminate approximately one-sixth of all causes of global warming to date.

So why then didn’t anybody think of this before? Well, the thing is that methane is hard to scrub from the air because its overall concentrations are so low. However zeolite, the team explains, is really really good at capturing the gas due to its “porous molecular structure, relatively large surface area and ability to host copper and iron,” explains coauthor Ed Solomon, the Monroe E. Spaght Professor of Chemistry in the School of Humanities and Sciences. The whole process could be as simple as using powerful fans to push air through reactors full of zeolite and catalysts. This material can then be heat-treated to form and release carbon dioxide gas.

Now let’s talk money. If market prices for carbon offsets rise to $500 or more per ton this century as predicted by most relevant assessment models, the team writes, each ton of methane removed from the atmosphere could be worth more than $12,000. A zeolite reactor the size of a football field could thus produce millions of dollars a year in income while removing harmful methane from the air. This is very fortunate as, in my experience, nothing motivates people to care about the environment quite like making money from saving it.

In principle, the researchers add, the approach of converting a more harmful greenhouse gas to one that’s less potent could also apply to other greenhouse gases.

The paper “Methane removal and atmospheric restoration” has been published in the journal Nature Sustainability.

Ocean.

Climate change may make the oceans belch out CO2, study warns

As oceans warm up due to climate change, they’ll likely start generating a lot of CO2.

Ocean.

Image via Pixabay.

Despite being the largest carbon sink active today, oceans might become net emitters under warmer climates, a new study reports. The paper reports that warmer oceans lose some of their ability to store carbon, which will accelerate the rate of CO2 regeneration in many areas of the world. This will further reduce the ocean’s ability to store carbon, the authors explain.

Positive carbon loop

“The results are telling us that warming will cause faster recycling of carbon in many areas, and that means less carbon will reach the deep ocean and get stored there,” said study coauthor Robert Anderson, an oceanographer at Columbia University’s Lamont-Doherty Earth Observatory.

Ocean water soaks up roughly 25% of our carbon dioxide emissions year after year. While this process also involves abiotic chemical and physical processes, the lion’s share of that CO2 is gobbled up by plankton through photosynthesis. But, all plankton must die eventually, and when they do, these tiny marine plants sink to the bottom of the ocean — and the carbon they ‘ate’ goes down with them. It’s estimated that plankton produces around 40 to 50 billion tons of dry, solid organic carbon each year.

Some of this organic matter (and the carbon therein) gets locked into the depths for centuries at a time, but part of it gets consumed by aerobic bacteria before sinking into oxygen-free waters, the team writes. Those bacteria then expel it as carbon dioxide, pushing it back into the atmosphere. Only about 15% of plankton-derived carbon sinks to the bottom of the sea, the authors estimate. They further report that the environmental conditions that allow bacteria to recycle carbon are spreading as water temperatures rise.

The team used data from a 2013 research cruise from Peru to Tahiti. They focused on two distinct regions: nutrient-rich, highly productive waters off South America, and the largely infertile bodies of water that form the South Pacific Gyre. Instead of using traditional sampling methods — simple devices that trap particles as they sink — the team pumped large amounts of water from different depths and isolated particles and thorium isotopes. This approach allowed them to calculate the quantity of carbon sinking at different depth intervals, they explain, and much more reliably so — the technique yielded far more data than the traditional traps.

Deeply worrying

In the oxygenated upper waters layers off South America, the team reports, oxygen gets used up very quickly. It is consumed completely at about 150 meters of depth, halting aerobic activity. Organic matter that reaches this layer (called the oxygen minimum zone, OMZ) will sink to the bottom of the ocean. In the depths, oxygen levels do increase again, and aerobic bacteria start breaking down organic matter. However, any CO2 produced down that far will take centuries to get back into the air via upwelling currents.

The OMZ thus forms a sort of protective cap over any organic matter that sinks past it, according to the team. The common wisdom of today, held that organic matter produced near the surface makes it through the OMZ, and that most CO2 regeneration takes place in the deep ocean. However, only about 15% of this matter sinks past the OMZ, the team shows.

“People did not think that much regeneration was taking place in the shallower zone,” said the study’s lead author, Frank Pavia, a graduate student at Lamont-Doherty. “The fact that it’s happening at all shows that the model totally doesn’t work in the way we thought it did.”

As mean water temperatures in the ocean increase, OMZs will spread both horizontally and vertically, covering larger areas of ocean at shallower depths, the team estimates. At the same time, higher temperatures will drive bacterial activity above the OMZs. On one hand, this would allow more organic matter to sink undegraded into the deep. However, the increased rate of CO2 regeneration near the surface will counteract this increased trapping, the team says. Whether near surface regeneration or the cap provided by the OMZ might have a stronger effect is still something we need to look into, they explain. However, this shift in OMZs is definitely not good news, as they are not at all suitable for most marine life — and this shift will affect a lot of today’s key fishing areas.

In the South Pacific Gyre, the results were less ambiguous. There is far more regeneration near the warmer surface than previously estimated in this area. The South Pacific Gyre and similar current systems in other parts of the oceans are projected to grow as the oceans warm. The gyres will divide waters into warmer layers (on the surface) and colder ones (deeper down). Because much of the CO2 regeneration will take place in the warm, shallower waters, CO2 regeneration will pick up over wide spans of ocean, the team explains. And, unlike below the nearer-shore OMZs, “there is no counterbalancing effect in the gyres,” said Anderson.

“The story with the gyres is that over wide areas of the ocean, carbon storage is going to get less efficient.” (There are four other major gyres: the north Pacific, the south and north Atlantic, and the Indian Ocean.)

These are only parts of the ocean carbon cycle, the team notes. Abiotic reactions are responsible for significant exchanges of carbon between atmosphere and oceans, and these processes could interact with the biology in complex and unpredictable ways.

“This [the study] gives us information that we didn’t have before, that we can plug into future models to make better estimates,” said the study’s lead author, Frank Pavia, a graduate student at Lamont-Doherty.

The paper “Shallow particulate organic carbon regeneration in the South Pacific Ocean,” has been published in the journal PNAS.

City Traffic.

New research says traffic exhaust is giving millions of kids asthma all around the world

Traffic-associated pollution leads to roughly 4 million cases of asthma in children worldwide each year, a new study reports.

City Traffic.

Image via Pixabay.

The team looked at 125 cities around the world, keeping track of the nitrogen oxide (NO2) levels in their air, and how it related to new pediatric cases of asthma. The study, based on data from 2010 to 2015, estimates that 4 million children worldwide develop asthma each year due to NO2, with 64% of these new cases occurring in urban areas.

The gas accounted for anywhere between 6% (Orlu, Nigeria) to 48% (Shanghai, China) of these cases, the authors report. Overall, NO2’s contribution to new cases of pediatric asthma exceeded 20% in 92 cities, they add, in both developed and emerging economies.

Bad air

“Our findings suggest that millions of new cases of pediatric asthma could be prevented in cities around the world by reducing air pollution,” said Susan C. Anenberg, PhD, an associate professor of environmental and occupational health at Milken Institute SPH, and the study’s senior author.

“Improving access to cleaner forms of transportation, like electrified public transport and active commuting by cycling and walking, would not only bring down NO2 levels, but would also reduce asthma, enhance physical fitness, and cut greenhouse gas emissions.”

Asthma is a chronic disease that involves inflammation of the lung’s airways, making it hard (sometimes impossible) to breathe. It is estimated that 235 million people worldwide currently have asthma, varying in intensity from wheezing to life-threatening attacks. This study is the first to take a look at how traffic-related nitrogen dioxide fits into the asthma picture. The work relied on a method that takes into account high exposures to NO2  that occur near busy roads, Anenberg explains.

For the study, the team linked together global datasets of NO2 concentrations,  population distributions, and asthma incidence rates with epidemiological evidence relating traffic-derived NO2 pollution with asthma development in kids. This wealth of data allowed the team to estimate how many new cases of pediatric asthma are attributable to NO2 pollution in the 194 countries and 125 major cities they studied.

Here are some key takeaways:

  • Roughly 4 million children developed asthma, each year, from 2010 to 2015 due to NO2 pollution (primarily from motor vehicle exhaust).
  • NO2 accounted for between 6% to 48% of pediatric asthma incidence. Its contribution exceeded 20% in 92 cities located in developed and emerging economies.
  • The ten highest NO2 contributions were estimated for eight cities in China (37 to 48% of pediatric asthma incidence) followed by Moscow, Russia and Seoul, South Korea, both at 40%.
  • In the US, the top-five most affected cities (as judged by percentage of pediatric asthma cases linked to polluted air) are Los Angeles, New York, Chicago, Las Vegas, and Milwaukee
  • China had the largest national health burden associated with air pollution at 760,000 cases of asthma per year, followed by India at 350,000, and the United States at 240,000.
  • In general, cities with high NO2 concentrations also had high levels of greenhouse gas emissions.

The World Health Organization (WHO) has set Air Quality Guidelines for NO2 and other air pollutants. For NO2, that guideline pins about 21 parts per billion for annual average levels as being safe. The researchers estimate that most children live in areas that conform to this guideline, but say that 92% of new pediatric asthma cases attributable to NO2 sprung up in areas that met the WHO guidelines.

“That finding suggests that the WHO guideline for NO2 may need to be re-evaluated to make sure it is sufficiently protective of children’s health,” said Pattanun Achakulwisut, PhD, lead author of the paper and a postdoctoral scientist at Milken Institute SPH.

The team, however, is confident that we can do better. Many of the solutions aimed at scrubbing cities of the greenhouse gases in their air would also reduce NO2 levels, thus helping prevent new cases of asthma.

The paper “Global, national, and urban burdens of paediatric asthma incidence attributable to ambient NO2 pollution: estimates from global datasets” has been published in The Lancet Planetary Health journal.

Glacier ice.

Ice ages may be caused by tectonic activity in the tropics, new study proposes

New research says that the Earth’s past ice ages may have been caused by tectonic pile-ups in the tropics.

Glacier ice.

A crevasse in a glacier.
Image via Pixabay.

Our planet has braved three major ice ages in the past 540 million years, seeing global temperatures plummet and ice sheets stretching far beyond the poles. Needless to say, these were quite dramatic events for the planet, so researchers are keen to understand what set them off. A new study reports that plate tectonics might be the culprit.

Cold hard plates

“We think that arc-continent collisions at low latitudes are the trigger for global cooling,” says Oliver Jagoutz, an associate professor in MIT’s Department of Earth, Atmospheric, and Planetary Sciences and a co-author of the new study.

“This could occur over 1-5 million square kilometers, which sounds like a lot. But in reality, it’s a very thin strip of Earth, sitting in the right location, that can change the global climate.”

“Arc-continent collisions” is a term that describes the slow, grinding head-butting that takes place when a piece of oceanic crust hits a continent (i.e. continental crust). Generally speaking, oceanic crust (OC) will slip beneath the continental crust (CC) during such collisions, as the former is denser than the latter. Arc-continent collisions are a mainstay of orogen (mountain range) formation, as they cause the edges of CC plates ‘wrinkle up’. But in geology, as is often the case in life, things don’t always go according to plan.

The study reports that the last three major ice ages were preceded by arc-continent collisions in the tropics which exposed tens of thousands of kilometers of oceanic, rather than continental, crust to the atmosphere. The heat and humidity of the tropics then likely triggered a chemical reaction between calcium and magnesium minerals in these rocks and carbon dioxide in the air. This would have scrubbed huge quantities of atmospheric CO2 to form carbonate rocks (such as limestone).

Over time, this led to a global cooling of the climate, setting off the ice ages, they add.

The team tracked the movements of two suture zones (the areas where plates collide) in today’s Himalayan mountains. Both sutures were formed during the same tectonic migrations, they report: one collision 80 million years ago, when the supercontinent Gondwana moved north creating part of Eurasia, and another 50 million years ago. Both collisions occurred near the equator and proceeded global atmospheric cooling events by several million years.

In geological terms, ‘several million years’ is basically the blink of an eye. So, curious to see whether one event caused the other, the team analyzed the rate at which oceanic rocks known as ophiolites can react to CO2 in the tropics. They conclude that, given the location and magnitude of the events that created them, both of the sutures they investigated could have absorbed enough CO2 to cool the atmosphere enough to trigger the subsequent ice ages.

Another interesting find is that the same processes likely led to the end of these ice ages. The fresh oceanic crust progressively lost its ability to scrub CO2 from the air (as the calcium and magnesium minerals transformed into carbonate rocks), allowing the atmosphere to stabilize.

“We showed that this process can start and end glaciation,” Jagoutz says. “Then we wondered, how often does that work? If our hypothesis is correct, we should find that for every time there’s a cooling event, there are a lot of sutures in the tropics.”

The team then expanded their analysis to older ice ages to see whether they were also associated with tropical arc-continent collisions. After compiling the location of major suture zones on Earth from pre-existing literature, they reconstruct their movement and that of the plates which generated them over time using computer simulations.

All in all, the team found three periods over the last 540 million years in which major suture zones (those about 10,000 kilometers in length) were formed in the tropics. Their formation coincided with three major ice ages, they add: one the Late Ordovician (455 to 440 million years ago), one in the Permo-Carboniferous (335 to 280 million years ago), and one in the Cenozoic (35 million years ago to present day). This wasn’t a happy coincidence, either. The team explains that no ice ages or glaciation events occurred during periods when major suture zones formed outside of the tropics.

“We found that every time there was a peak in the suture zone in the tropics, there was a glaciation event,” Jagoutz says. “So every time you get, say, 10,000 kilometers of sutures in the tropics, you get an ice age.”

Jagoutz notes that there is a major suture zone active today in Indonesia. It includes some of the largest bodies of ophiolite rocks in the world today, and Jagoutz says it may prove to be an important resource for absorbing carbon dioxide. The team says that the findings lend some weight to current proposals to grind up these ophiolites in massive quantities and spread them along the equatorial belt in an effort to counteract our CO2 emissions. However, they also point to how such efforts may, in fact, produce additional carbon emissions — and also suggest that such measures may simply take too long to produce results within our lifetimes.

“It’s a challenge to make this process work on human timescales,” Jagoutz says. “The Earth does this in a slow, geological process that has nothing to do with what we do to the Earth today. And it will neither harm us, nor save us.”

The paper “Arc-continent collisions in the tropics set Earth’s climate state” has been published in the journal Science.

Liquid cerium catalyst.

New process could capture CO2 and make it coal again

Instead of burning coal and releasing CO2, new research plans to absorb CO2 and produce coal.

Charcoal.

Image via Pixabay.

A new breakthrough could allow us to burn our coal and have it, too. Researchers from Australia, Germany, China, and the US have worked together to develop a carbon storage method that can turn CO2 gas into solid carbon particles with high efficiency. Their approach could help us scrub the atmosphere of (some of) the greenhouse emissions we produce — with a certain dash of style.

Coal idea

“While we can’t literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock,” says Torben Daeneke, an Australian Research Council DECRA Fellow and paper co-author.

The idea of permanently removing CO2 from the atmosphere isn’t new — in fact, it’s heavily considered as a solution to our self-induced climate woes. We’ve developed several ways to go about it, but they simply aren’t viable yet. Current carbon capture technologies turn the gas into a liquid form, which is then carted away to be injected underground. However, the process requires high temperatures (which means high costs) and there are environmental concerns regarding possible leaks from storage sites.

The team’s approach, however, relies on an electrochemical technique to capture atmospheric CO2 and turn it into solid, easy to store carbon.

“To date, CO2 has only been converted into a solid at extremely high temperatures, making it industrially unviable,” Daeneke explains. “By using liquid metals as a catalyst, we’ve shown it’s possible to turn the gas back into carbon at room temperature, in a process that’s efficient and scalable.”

“While more research needs to be done, it’s a crucial first step to delivering solid storage of carbon.”

The liquid metal cerium (Ce) catalyst has certain surface properties that make it a very good electrical conductor — the current also chemically activates the catalyst’s surface.

Liquid cerium catalyst.

Schematic of the catalytic process.
Image credits Dorna Esrafilzadeh, (2019), Nature.

The whole process starts with the team dissolving carbon dioxide gas in a liquid-filled beaker and a small quantity of the liquid metal. When charged with electrical current, this catalyst slowly starts converting the CO2 into solid flakes of carbon on its surface and promptly falls off, so the process can be maintained indefinitely.

“A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles,” says Dr Dorna Esrafilzadeh, a Vice-Chancellor’s Research Fellow in RMIT’s School of Engineering and the paper’s lead author.

“The process also produces synthetic fuel as a by-product, which could also have industrial applications.”

The paper “Room temperature CO2 reduction to solid carbon species on liquid metals featuring atomically thin ceria interfaces” has been published in the journal Nature.

Mars.

Natural batteries formed Mars’ organic carbon

Mars’ organic carbon was formed in batteries. Huge, naturally-occurring batteries — sort-of.

Mars.

Image credits Aynur Zakirov.

The organic carbon found on Mars has both excited and perplexed researchers. When it was first discovered, this element reignited our hopes of finding life on the red planet. Later, it became apparent that things aren’t so straightforward. However, that still left us with a question: if not life, then what, exactly, created all this organic carbon?

New research from the Carnegie Institution for Science shows that the answer is even more surprising than you’d have assumed. Mars’ organic carbon may originate from a series of electrochemical reactions between briny liquids and volcanic minerals — in essence, natural batteries.

An electrifying find

“Revealing the processes by which organic carbon compounds form on Mars has been a matter of tremendous interest for understanding its potential for habitability,” says lead researcher Andrew Steele.

The research has roots in Steele’s previous work. Back in 2012, he led a team that found organic carbon in 10 Martian meteorites. The team also established that the carbon content wasn’t due to contamination from Earth and that it didn’t have a biological origin. All organic molecules contain carbon and hydrogen, and some include oxygen, nitrogen, sulfur, or other elements. Organic compounds are commonly associated with life, although they can be created by non-biological processes as well, which are referred to as abiotic organic chemistry.

To find out how this organic carbon was generated, the team worked with a trio of Martian meteorites that made their way to Earth — Tissint, Nakhla, and NWA 1950. Chemical analysis revealed that the hunks of rock contain organic carbon. Furthermore, its very similar chemically to the organic carbon found during the Mars Science Laboratory’s rover missions.

After establishing that the rocks did indeed contain organic carbon, and that its very likely originated on Mars, the team looked at their mineral makeup. Using advanced microscopy and spectroscopy, they determined that the organic compounds were likely created through electrochemical corrosion of minerals in Martian rocks by a surrounding salty liquid, brine.

“The discovery that natural systems can essentially form a small corrosion-powered battery that drives electrochemical reactions between minerals and surrounding liquid has major implications for the astrobiology field,” Steele explained.

Such processes aren’t new to science. We’ve seen evidence of them on Earth — particularly early in this planets’ history –, and now, we seem to have found some underway on Mars. That’s actually pretty good news — it means that they should, in theory, be able to take place anywhere igneous (volcanic) rocks are surrounded by brine. This means there’s a chance of seeing such processes unfolding in the subsurface oceans of Jupiter’s moon Europa or Saturn’s moon Enceladus. If this is the case, they could be used as a source of CO2 to jump-start potential colonies.

The paper “Organic synthesis on Mars by electrochemical reduction of CO2” has been published in the journal Science Advances.

Titanium dioxide nanoparticles.

White paint might be causing a lot of Type 2 diabetes, preliminary research finds

A pilot study from The University of Texas at Austin suggests white paint and Type 2 diabetes might be linked.

Titanium dioxide nanoparticles.

Titanium dioxide nanoparticles.
Image credits University of Turin.

In the mid-20th century, titanium dioxide (TiO2) overthrew lead-based compounds (which were really toxic) as the go-to white pigment. Today, it’s the most widely used white pigment, mixed into everything from food and medication to plastic and paper. We rely on this substance a lot, as we’re producing in excess of 9 million metric tons of the stuff per year.

However, the pigment may not be as harmless as we’ve believed. Preliminary research has found TiO2 crystals embedded in pancreas tissue afflicted with Type 2 diabetes (T2D).

The white tint of diabetes

The team worked with 11 pancreas specimens, 8 from donors with T2D and 3 from donors who didn’t have the condition. The specimens were provided by the Juvenile Diabetes Research Foundation nPOD at the University of Florida at Gainesville.

The last three samples didn’t contain any detectable levels of TiO2 crystals. The 8 specimens with T2D, however, all had TiO2 crystals embedded in their tissues. The researchers report finding over 200 million TiO2 crystallites per gram of TiO2 particles in the specimens of donors with diabetes.

It’s particularly suspicious to find TiO2 crystals in all of the T2D specimens since titanium dioxide doesn’t have any known role in human biology. Furthermore, while plenty of different salts and other metallic compounds have a role to play in our bodies, there is no known role for titanium salt or another type of titanium compound in our biochemistry.

“Our initial findings raise the possibility that Type 2 diabetes could be a chronic crystal-associated inflammatory disease of the pancreas, similar to chronic crystal-caused inflammatory diseases of the lung such as silicosis and asbestosis,” said Adam Heller, the study’s lead author.

Heller is a professor in the McKetta Department of Chemical Engineering in the Cockrell School of Engineering. He has had a life-long career of diabetes research, for which he received the National Medal of Technology and Innovation in 2007.

Statistics from the World Health Organization show that the number of diabetes patients has quadrupled over the past four decades, reaching some 425 million known cases today. T2D represents the majority of these cases.

Although rising obesity rates and higher average life expectancy (which means more people reach old age) are considered the main factors driving this increase in T2D, the team isn’t convinced. Heller suggests that the increased use of titanium dioxide during these past few decades may be a key, if overlooked, driver of the condition.

“The increased use of titanium dioxide over the last five decades could be a factor in the Type 2 diabetes epidemic,” he said.

“The dominant T2D-associated pancreatic particles consist of TiO2 crystals, which are used as a colorant in foods, medications and indoor wall paint, and they are transported to the pancreas in the bloodstream. The study raises the possibility that humanity’s increasing use of TiO2 pigment accounts for part of the global increase in the incidence of T2D.”

The findings, right now, are far from convincing — but they are, potentially, very far-reaching. This was only a pilot study, with a very limited sample; Heller will repeat the study using a larger sample.

The paper “Association of Type 2 Diabetes with Submicron Titanium Dioxide Crystals in the Pancreas” has been published in the journal Chemical Research in Toxicology.

Bali eruption.

Ancient volcanism shows our emissions can trigger a mass marine extinction

Ancient volcanism offers a glimpse into the future effects of climate change.

Bali eruption.

Volcanic eruption in Bali, Indonesia.
Image credits Alit Suarnegara.

Right now, global climate patterns are swinging wildly (in geological terms), powered by all the greenhouse gases we’re pumping in the atmosphere. We have some broad idea of what these changes will entail, but we don’t know the details — and not knowing what to expect in such circumstances is quite scary. One thing we do know for sure right now is that the high concentrations of carbon dioxide in the atmosphere are draining oceans of oxygen. It’s happening faster than anything similar we’ve ever seen and has researchers worried and scrambling to find solutions.

For that, however, we’ll need to know what to expect. One team of researchers from Florida State University (FSU) dredged the geological record for similar events to use as a guideline. The magnitude and sheer destructiveness of what they found suggests that we were right to worry.

Volca-no

The team used ancient volcanism as a proxy for today’s anthropic emissions. Millions of years ago, during the Toarcian Oceanic Anoxic Event (T-OAE, during the Early Jurassic), powerful eruptions belched large quantities of carbon dioxide into the atmosphere. Oxygen levels in ocean waters soon plummeted. Most marine life followed suit, leading to a devastating mass extinction.

“We want to understand how volcanism, which can be related to modern anthropogenic carbon dioxide release, manifests itself in ocean chemistry and extinction events,” said study co-author Jeremy Owens.

“Could this be a precursor to what we’re seeing today with oxygen loss in our oceans? Will we experience something as catastrophic as this mass extinction event?”

The team set out to reconstruct ocean oxygen levels during the Early Jurassic in order to better understand the mass extinction event during the T-OAE. Their research reinforces previous findings regarding the (bad) effects of increased ocean temperature and acidification on marine life. However, it also revealed the importance of a third factor, oxygen level change, in leading to such an event.

Toarcian paleogeo.

Image credits Scotese CR (2001), Atlas of Earth History via R. Them et al., 2018, PNAS.

For the study, the team retrieved samples of ancient rock formations from North America and Europe. Thallium isotope analysis performed at the FSU-based National High Magnetic Field Laboratory revealed that oxygen levels in the oceans started to drop several hundred thousands of years before the interval we ascribe to the T-OAE. This initial drop was caused by massive bouts of volcanic activity, they explain, adding that it’s not that different a process from modern anthropic emissions of CO2.

“Over the past 50 years, we’ve seen that a significant amount of oxygen has been lost from our modern oceans,” says Theodore Them, a postdoctoral researcher at FSU who led the study. “While the timescales are different, past volcanism and carbon dioxide increases could very well be an analog for present events.”

“As a community, we’ve suggested that sediments deposited during the T-OAE were indicative of widespread oxygen loss in the oceans, but we’ve never had the data until now.”

High atmospheric levels of carbon dioxide increase average temperatures on the planet. This sets into motion multiple chains of events (chemical, biological, as well as hydrological) that compound to remove oxygen from ocean water. Ultimately, this process resulted in severe oceanic deoxygenation and mass extinction of marine life, which we see in the geological record as the T-OAE.

Extinction event

Sequence of events culminating in the Early Jurassic T-OAE. The massive die-off worked to sequester large amounts of carbon (δ13C line) from the atmosphere, allowing conditions to eventually stabilize. Top bars represent biodiversity.
Image credits R. Them et al., 2018, PNAS.

The findings help flesh out our understanding of how Earth’s systems function. But they also point to a worrying precedent. We’re already seeing signs of ocean acidification, increased average temperatures, and of falling levels of oxygen in ocean water. It’s safe to assume that the interplay between these events will have the same results as in the Early Jurassic. Should we continue pumping greenhouse gases such as CO2 in the atmosphere, we might just usher in an ocean mass extinction upon ourselves — one that will likely take society as we know it down, too.

“It’s extremely important to study these past events,” Them said. “It seems that no matter what event we observe in Earth’s history, when we see carbon dioxide concentrations increasing rapidly, the result tends to be very similar: a major or mass extinction event. This is another situation where we can unequivocally link widespread oceanic deoxygenation to a mass extinction.”

Not all is lost, however. All out tech and know-how put us in this position, that’s true, but it also offers the way out. There are steps we can take to stop or at least slow down the rate of oxygen loss in our oceans, the team notes. For example, maintaining environments that absorb and store carbon dioxide (such as wetlands or estuaries) could help reduce the effect of our emissions. The single biggest change we can make, however, is to de-couple our industries and economies from fossil fuels — efforts are already underway, but it never hurts to double down.

Personal efforts also help. Many of the things you can do to reduce your impact on the planet are also quite healthy and beneficial choices on an individual level: drive less, to reduce the level of emissions you put in the air and get some exercise, too. Eat more veggies, cut out as much meat and dairy as you’re comfortable too, or just be more selective about what type of animal protein you eat — good for your health, your wallet, and the planet! Finally, waste not — it helps to reduce emissions from industry, reduces trash, and will give you a mood boost.

The paper “Thallium isotopes reveal protracted anoxia during the Toarcian (Early Jurassic) associated with volcanism, carbon burial, and mass extinction” has been published in the journal Proceedings of the National Academy of Sciences.

Trees trade carbon through their roots, using symbiotic fungi networks

A forest’s trees capture carbon not only for themselves, but also engage in an active “trade” of sorts with their neighbors, a new study found. University of Basel botanists found that this process, conducted by symbiotic fungi in the forest’s soil, takes place even among trees of different species.

Image credits pexel user veeterzy

Plants rely on photosynthesis for energy and growth. Through this process, carbon is extracted from atmospheric CO2 and used to synthesize carbohydrates (sugars). These are then further processed into stuff that a growing plant needs, like cellulose, lignin (a polymer that gives wood its resilience,) protein and lipids. Some of the sugars get sent down to the roots and shared with the tree’s underground symbiotic fungi (known as mycorrhizal fungi) in exchange for nutrients that they extract from the soil.

It’s a very effective process, providing the plant with everything it needs without it having to move a single branch. But it all falls apart without enough carbon dioxide or light, and in a thick forest these can be hard to come by. So then, why don’t young trees just wither, choked under the canopy of much bigger, older trees? Well, the answer might lie in a type of tree socialism — and mycorrhizal fungi make it all happen.

Dr. Tamir Klein and Prof. Christian Körner of the University of Basel, working with Dr. Rolf Siegwolf of the Paul Scherrer Institute (PSI) have found that forest trees use the fungal network to trade sugars among themselves. The researchers used a construction crane and a system of fine tubes to saturate the crowns of 120 year old, 40 meter tall spruce trees in a forest near Basel with labeled CO2. The gas was processed to contain less of the heavier 13C isotope than normal air.

Image credits University of Basel

For the trees, this CO2 was just as good as the rest and they gulped it all up. But it allowed the team to track the carbon atoms through the tree using mass spectrometers. They traced the atoms on their way from crown to the roots of the spruce trees and as they entered the fungi. But then something unexpected happened: neighboring trees (even those of other species) also showed the same markers even though they had not received the labelled carbon dioxide.

If the gas would have been absorbed directly by these trees, then some of it would have been caught by the underbrush too — understory plants however remained entirely unmarked. And the differentiated carbon was only found in their roots. The only explanation for its presence is an exchange between the trees through the tiny filaments of the mycorrhizal fungi.

The team considers this natural exchange of large quantities of carbon “a big surprise,” especially as it also takes place among completely unrelated species. They estimate that in an 68 meter wide and 100 meter long area the fungal network can transport around 280 kilograms of carbon a year. That accounts for nearly half the carbon in the trees’ fine roots.

“Evidently the forest is more than the sum of its trees,” Prof. Christian Körner comments.

The full paper, titled “Belowground carbon trade among tall trees in a temperate forest” has been published online in the journal Science and can be read here.