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We may have to abandon concrete to fight climate change, architectural experts say
The building material seems so ubiquitous — what can we use in its place?

- Concrete is a surprisingly dangerous contributor of greenhouse gas emissions.
- For years, architects haven't been concerned with these emissions since concrete buildings last for so long; their carbon footprint is spread out over their entire lifespan.
- However, as we approach climate "tipping points," the front-loaded cost of concrete construction may be too high.
A group of experts at the Architecture of Emergency climate summit in London have identified an unlikely source of greenhouse gas emissions: concrete.
"If we invented concrete today, nobody would think it was a good idea," said architectural engineer and panel member Michael Ramage. "We've got this liquid and you need special trucks, and it takes two weeks to get hard. And it doesn't even work if you don't put steel in it."
The four billion tons of concrete produced for construction each year accounts for 8 percent of the world's carbon dioxide emissions, mainly through the production of clinker. Clinker serves as a crucial binding element in cement, the primary ingredient of concrete, and is produced by heating limestone and clay to around 1,400°C (about 2,500°F). Heating limestone (CaCO3) to these temperatures, however, causes a chemical reaction called calcination that results in lime (CaO) and carbon dioxide (CO2) as a waste product. Roughly half of concrete's carbon dioxide emissions is due to calcination, while another 40 percent comes from burning fossil fuels to heat up limestone to the point where this chemical reaction can occur. The last 10 percent comes from the fuel used in the mining and transportation process.
Eight percent might seem like a large slice of the world's carbon dioxide pie, but architectural experts haven't been particularly concerned about this figure until recently. The reason why has to do with concrete's longevity. Normally when calculating a building's total carbon emissions, said Phineas Harper of Dezeen magazine, architects take the amount of carbon needed to construct a building and divide it over the building's total lifespan. "That gives you your per-year carbon emissions," said Harper. However, in our current climate situation, this kind of thinking is "dead wrong."
Had we taken climate change more seriously a hundred years ago, this would probably be fine. But as it stands today, we have only a few short years before we reach climate "tipping points," events that create negative feedback loops in the climate that are very difficult to reverse. The melting of polar ice, which reflects sunlight and contains locked-away greenhouse gases, is a well-known example of such a tipping point. So too is deforestation in rainforests, which increases the likelihood of local droughts, killing even more trees.
As a result, the front-heavy carbon load of concrete buildings inadvertently contribute more to climate change than any straightforward calculation may suggest.
Looking for alternatives
So, if we can't build sustainably with concrete, what other materials can we build with? Ken de Cooman, founder of BC Architects & Studies, discussed how his firm is using materials primarily formed from the earth, like compressed-earth bricks. There are also biocomposite materials, which are formed out of natural fibers embedded in a matrix. Hempcrete, for instance, is a biocomposite of hemp and lime that is actually carbon negative since hemp absorbs CO2 as it grows.
Interestingly, one of the best candidates for replacing concrete in construction projects is something of an old-fashioned solution — timber. One might wonder if using timber is all that wise given the importance of forests in maintaining the health of our environment, this might seem counterintuitive. Ramage acknowledged that building out of timber would require sustainable practices. In order to make construction using timber sustainable, a number of trees would have to be planted for every tree that is cut down. And, added Ramage,"It's important to remember that every kilogram of timber we build with holds the equivalent of 1.8 kilograms of carbon dioxide." Unlike concrete, timber stores carbon dioxide, lowering a building's overall carbon footprint.
A photo of Andrew Waugh's all-timber building constructed in North London.
Image source: Architecture of Emergency, 2019
As an example of this, architect Andrew Waugh described a building his firm built in North London.
"We built the entire building from solid timber from the first floor up. So all the internal walls, external walls, lift shafts, staircases, all in timber. … It's about 2.8 trees per person that live in that building and for every one of those trees that was cut down to build that building five more were planted in its place."
Timber is growing in popularity as a construction material, both because of its greater sustainability and because of advances that have enabled it to be used in taller buildings, like cross-laminated timber. These developments have not left the concrete industry too happy, which has taken out advertisements emphasizing the flammability of timber buildings and the environmental impacts of cutting down trees.
"We must be doing something right," said Waugh, "because, much like the tobacco industry in the 1980s and 1990s, Big Concrete is beginning to fight back."
Many of the methods we can employ to address climate change can seem radical. After all, many climate change activists ask that we stop engaging in many activities that have been a part of our lives for decades. But the climate crisis didn't suddenly arise out of nowhere — it's these activities that have, bit by bit, added momentum to this phenomenon.
Reversing that momentum will mean cutting back on fossil fuels, eating meat, building in concrete, and many more activities that we have taken for granted.
Update Tuesday, October 15, 2019: This story was updated to specify when and how carbon emissions are released during the cement production process.
Weird science shows unseemly way beetles escape after being eaten
Certain water beetles can escape from frogs after being consumed.
R. attenuata escaping from a black-spotted pond frog.
- A Japanese scientist shows that some beetles can wiggle out of frog's butts after being eaten whole.
- The research suggests the beetle can get out in as little as 7 minutes.
- Most of the beetles swallowed in the experiment survived with no complications after being excreted.
In what is perhaps one of the weirdest experiments ever that comes from the category of "why did anyone need to know this?" scientists have proven that the Regimbartia attenuata beetle can climb out of a frog's butt after being eaten.
The research was carried out by Kobe University ecologist Shinji Sugiura. His team found that the majority of beetles swallowed by black-spotted pond frogs (Pelophylax nigromaculatus) used in their experiment managed to escape about 6 hours after and were perfectly fine.
"Here, I report active escape of the aquatic beetle R. attenuata from the vents of five frog species via the digestive tract," writes Sugiura in a new paper, adding "although adult beetles were easily eaten by frogs, 90 percent of swallowed beetles were excreted within six hours after being eaten and, surprisingly, were still alive."
One bug even got out in as little as 7 minutes.
Sugiura also tried putting wax on the legs of some of the beetles, preventing them from moving. These ones were not able to make it out alive, taking from 38 to 150 hours to be digested.
Naturally, as anyone would upon encountering such a story, you're wondering where's the video. Thankfully, the scientists recorded the proceedings:
The Regimbartia attenuata beetle can be found in the tropics, especially as pests in fish hatcheries. It's not the only kind of creature that can survive being swallowed. A recent study showed that snake eels are able to burrow out of the stomachs of fish using their sharp tails, only to become stuck, die, and be mummified in the gut cavity. Scientists are calling the beetle's ability the first documented "active prey escape." Usually, such travelers through the digestive tract have particular adaptations that make it possible for them to withstand extreme pH and lack of oxygen. The researchers think the beetle's trick is in inducing the frog to open a so-called "vent" controlled by the sphincter muscle.
"Individuals were always excreted head first from the frog vent, suggesting that R. attenuata stimulates the hind gut, urging the frog to defecate," explains Sugiura.
For more information, check out the study published in Current Biology.
Stressed-out mothers are twice as likely to give birth to a girl
New research from the University of Granada found that stress could help determine sex.
Stress in the modern world is generally viewed as a hindrance to a healthy life.
Indeed, excess stress is associated with numerous problems, including cardiovascular disease, high blood pressure, insomnia, depression, obesity, and other conditions. While the physiological mechanisms associated with stress can be beneficial, as Kelly McGonigal points out in The Upside of Stress, the modern wellness industry is built on the foundation of stress relief.
The effects of stress on pregnant mothers is another longstanding area of research. For example, what potential negative effects do elevated levels of cortisol, epinephrine, and norepinephrine have on fetal development?
A new study, published in the Journal of Developmental Origins of Health and Disease, investigated a very specific aspect of stress on fetuses: does it affect sex? Their findings reveal that women with elevated stress are twice as likely to give birth to a girl.
For this research, the University of Granada scientists recorded the stress levels of 108 women before, during, and after conception. By testing cortisol concentration in their hair and subjecting the women to a variety of psychological tests, the researchers discovered that stress indeed influences sex. Specifically, stress made women twice as likely to deliver a baby girl.
The team points out that their research is consistent with other research that used saliva to show that stress resulted in a decreased likelihood of delivering a boy.
Maria Isabel Peralta RamírezPhoto courtesy of University of Granada
Lead author María Isabel Peralta Ramírez, a researcher at the UGR's Department of Personality, Evaluation and Psychological Treatment, says that prior research focused on stress levels leading up to and after birth. She was interested in stress's impact leading up to conception. She says:
"Specifically, our research group has shown in numerous publications how psychological stress in the mother generates a greater number of psychopathological symptoms during pregnancy: postpartum depression, a greater likelihood of assisted delivery, an increase in the time taken for lactation to commence (lactogenesis), or inferior neurodevelopment of the baby six months after birth."
While no conclusive evidence has been rendered, the research team believes that activation of the mother's endogenous stress system during conception sets the concentration of sex hormones that will be carried throughout development. As the team writes, "there is evidence that testosterone functions as a mechanism when determining the baby's sex, since the greater the prenatal stress levels, the higher the levels of female testosterone." Levels of paternal stress were not factored into this research.
Previous studies show that sperm carrying an X chromosome are better equipped to reach the egg under adverse conditions than sperm carrying the Y chromosome. Y fetuses also mature slowly and are more likely to produce complications than X fetuses. Peralta also noted that there might be more aborted male fetuses during times of early maternal stress, which would favor more girls being born under such circumstances.
In the future, Peralta and her team say an investigation into aborted fetuses should be undertaken. Right now, the research was limited to a small sample size that did not factor in a number of elements. Still, the team concludes, "the research presented here is pioneering to the extent that it links prenatal stress to the sex of newborns."
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Stay in touch with Derek on Twitter and Facebook. His most recent book is "Hero's Dose: The Case For Psychedelics in Ritual and Therapy."
The cost of world peace? It's much less than the price of war
The world's 10 most affected countries are spending up to 59% of their GDP on the effects of violence.
- Conflict and violence cost the world more than $14 trillion a year.
- That's the equivalent of $5 a day for every person on the planet.
- Research shows that peace brings prosperity, lower inflation and more jobs.
- Just a 2% reduction in conflict would free up as much money as the global aid budget.
- Report urges governments to improve peacefulness, especially amid COVID-19.
What is the price of peace?
Or put another way, how much better off would we all be in a world where armed conflict was avoided?
Around $14.4 trillion in 2019, according to the Institute for Economics and Peace (IEP) which crunched the numbers. That's about $5 a day for every person on the planet.
To give some context, 689 million people - more than 9% of the world's population - live on less than $1.90 a day, according to World Bank figures, underscoring the potential impact peace-building activities could have.
Just over 10% of global GDP is being spent on containing, preventing and dealing with the consequences of violence. As well as the 1.4 million violent deaths each year, conflict holds back economic development, causes instability, widens inequality and erodes human capital.
Putting a price tag on peace and violence helps us see the disproportionately high amounts spent on creating and containing violent acts compared to what is spent on building resilient, productive, and peaceful societies.
—Steve Killelea, founder and executive chairman, Institute for Economics & Peace (IEP)
The cost of violence
In a report titled "The Economic Value of Peace 2021", the IEP says that for every death from violent conflict, 40 times as many people are injured. The world's 10 most affected countries are spending up to 59% of their GDP on the effects of violence.
Grounds for hope
But the picture is not all bleak. The economic impact of violence fell for the second year in a row in 2019, as parts of the world became more peaceful.
The global cost dropped by $64 billion between 2018 and 2019, even though it was still $1.2 trillion higher than in 2012.
In five regions of the world the costs increased in 2019. The biggest jump was in Central America and the Caribbean, where a rising homicide rate pushed the cost up 8.3%.
Syria, with its ongoing civil war, suffered the greatest economic impact with almost 60% of its GDP lost to conflict in 2019. That was followed by Afghanistan (50%) and South Sudan (46%).
The report makes a direct link between peace and prosperity. It says that, since 2000, countries that have become more peaceful have averaged higher GDP growth than those which have become more violent.
"This differential is significant and represents a GDP per capita that is 30% larger when compounded over a 20-year period," the report says adding that peaceful countries also have substantially lower inflation and unemployment.
"Small improvements in peace can have substantial economic benefits," it adds. "For example, a 2% reduction in the global impact of violence is roughly equivalent to all overseas development aid in 2019."
Equally, the total value of foreign direct investment globally only offsets 10% of the economic impact of violence. Authoritarian regimes lost on average 11% of GDP to the costs of violence while in democracies the cost was just 4% of GDP.
And the gap has widened over time, with democracies reducing the cost of violence by almost 16% since 2007 while in authoritarian countries it has risen by 27% over the same period.
The report uses 18 economic indicators to evaluate the cost of violence. The top three are military spending (which was $5.9 trillion globally in 2019), the cost of internal security which makes up over a third of the total at $4.9 trillion and homicide.
Peace brings prosperity
The formula also contains a multiplier effect because as peace increases, money spent containing violence can instead be used on more productive activities which drive growth and generate higher monetary and social returns.
"Substantial economic improvements are linked to improvements in peace," says the report. "Therefore, government policies should be directed to improving peacefulness, especially in a COVID-19 environment where economic activity has been subdued."
The IEP says what it terms "positive peace" is even more beneficial than "negative peace" which is simply the absence of violence or the fear of violence. Positive peace involves fostering the attitudes, institutions & structures that create and sustain peaceful societies.
The foundations of a positively peaceful society, it says, are: a well functioning government, sound business environment, acceptance of the rights of others, good relations with neighbours, free flow of information, high levels of human capital, low levels of corruption and equitable distribution of resources.
The World Economic Forum's report Mobilizing the Private Sector in Peace and Reconciliation urged companies large and small to recognise their potential to work for peace quoting the former Goldman Sachs chair, the late Peter Sutherland, who said: "Business thrives where society thrives."
Reprinted with permission of the World Economic Forum. Read the original article.
The evolution of modern rainforests began with the dinosaur-killing asteroid
The lush biodiversity of South America's rainforests is rooted in one of the most cataclysmic events that ever struck Earth.
