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We, and all other complex life, require stability to evolve. Planetary conditions needed to be benign and long-lived for creatures like us and our multicellular brethren to appear and to persist. On Earth, chemical cycling provides much of the needed stability.

Chemical cycling between the land, atmosphere, lifeforms, and oceans is enormously complex and difficult to study. Typically, researchers try to isolate one cycle and study it. However, new research is examining Earth’s chemical cycling more holistically to try to understand how the planet has stayed in the ‘sweet spot’ for so long.

Earth has supported complex life for hundreds of millions of years, possibly for more than a billion years. This is extremely rare, as far as we can tell. The vast majority of the exoplanets we’ve discovered are not in their stars’ habitable zones. They have very little chance of hosting any life, let alone complex life.

It’s possible that some planets experience a period of stability for much shorter periods of time than Earth. This may describe Mars. It was warm and wet and could’ve hosted simple life, but the planet lost most of its atmosphere and became uninhabitable. Now it’s cold, dry, and dead.

Earth robustly cycles the chemical elements through different systems and has done so for billions of years. Now, about 4.5 billion years after its formation, life is abundant on our precious planet. Biogeochemical cycles like the carbon cycle, the nitrogen cycle, and the methane cycle have allowed the planet to sustain its habitability.

New research published in the Proceedings of the National Academy of Sciences examines these cycles holistically, hoping to better understand the relationships between them. The research is “Balance and imbalance in biogeochemical cycles reflect the operation of closed, exchange, and open sets.” The lead author is Preston Cosslett Kemeny, a University of Chicago TC Chamberlain postdoctoral fellow.

“Overall, this work provides a systematic conceptual framework
for understanding balance and imbalance in global biogeochemical cycles.”

From “Balance and imbalance in biogeochemical cycles reflect the operation of closed, exchange, and open sets.”

Earth’s carbon cycle plays a dominant role in the climate. As carbon accumulates in the atmosphere, the planet warms. As carbon is sequestered into the mantle, the planet cools. Even though it’s been stable for a long time, research shows that small imbalances can upset the system.

What Kemeny and his co-researchers wanted to do was get back to the basics. They wanted to identify a framework for all the reactions, both large and small, that comprise Earth’s chemical cycles. What’s different in their work is that they didn’t specify how they all worked together, if they worked together, or how much they affected one another.

“Our approach provides a new way to identify the fundamental building blocks of stability in the chemical components of Earth’s climate—the underlying ways in which the climate can be stabilized over geological time due to the movement of elements across the ocean, atmosphere, and rock reservoirs,” said Kemeny.

Earth’s long-lasting habitability created the conditions for complex life like us to appear. That habitability is dependent on the complex interplay of chemistry between the ocean, atmosphere and land. This image, captured from the International Space Station 400km above Earth’s surface, shows our planet’s thin atmosphere. Image Credit: NASA

The researchers describe their effort as ‘agnostic’ and explain that it creates “… a systematic and simplified conceptual framework for understanding the function and evolution of global biogeochemical cycles.” They call it agnostic because it doesn’t specify the relationship between environmental conditions and the strength of biogeochemical processes. “By remaining agnostic to the relationships between environmental conditions and the intensity of biogeochemical processes, we sought to recognize and systematize patterns that underly the stability of major element cycles,” Kemeny explains on his website.

“This is an elegant, simplified way to think about an enormous problem, which organizes a lot of previous research on elemental cycles into packages of chemical reactions that can be balanced and understood,” said University of Chicago Assistant Professor Clara Blättler, senior author of the paper.

The complexity of Earth’s cycles makes them difficult to study. They work on long geological timescales, which puts us at a disadvantage. The planet’s carbon cycle illustrates this.

The movement of carbon plays an important role in regulating the planet’s climate. When carbon dioxide accumulates in the atmosphere, the atmosphere traps more heat, which warms up the oceans. However, carbon also creates a weak acid called carbonic acid that breaks rocks down faster. The carbon eventually finds its way to the ocean floor and becomes sequestered in rock. Carbon can also spend some time as part of living things before being sequestered into rock or fossil fuels. This sequestration of carbon eventually cools the planet but takes millions of years. Carbon is eventually returned to the atmosphere by volcanoes and by the burning of fossil fuels.

The Carbon cycle plays a dominant role in moderating Earth’s climate, but other chemical cycles influence it. Image Credit: U.S. DOE, Biological and Environmental Research Information System.

Trying to understand the carbon cycle is made more difficult by its interaction with other cycles. The Earth’s cycles also aren’t static. They change over time, adding to the complexity. There are also missing pieces from the large puzzle of Earth’s cycles. Researchers are forced to make assumptions to fill in the blanks.

Kemeny devotes much of his time to understanding Earth’s cycles, and he and his colleagues hope that their approach can yield better results. “Models of global element cycles seek to understand how biogeochemical processes and environmental conditions interact to sustain planetary habitability,” Kemeny writes on his website. “However, outcomes from such models often reflect specific interpretations of geochemical archives.”

The researchers think their approach may help overcome the obstacles to understanding Earth’s cycles. They employed a mathematical analysis to develop a framework identifying all of the major and minor cycles that contribute to Earth’s long-term habitability by balancing the carbon cycle.

The result was a new, more holistic way to look at Earth. The climate can be represented by a large set of interconnected chemical equations. These equations must balance over certain time periods to keep the carbon cycle stable and the Earth habitable.

The Sulphur Cycle is just one of Earth’s important cycles. It moves sulphur between rocks, water, and living things. Kemeny and his colleagues are trying to understand all of Earth’s cycles holistically rather than in isolation. Image Credit: By Bantle – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=20411832

Kemeny highlights one episode in Earth’s climate history to illustrate the point. The Cenozoic era began about 65.5 million years ago and is the era we live in now. The Cenozoic is a long-term cooling trend in Earth’s history, and the period that preceded it was a greenhouse climate. Kemeny and his colleagues say that their holistic approach can open a window into how the climate changed.

“For example, say that you are considering a hypothesis for why the climate changed in the past – such as the major cooling of the last 65 million years,” Kemeny said. “You can take this framework and use it to say: well, if X process increased or decreased, then it should have also caused Y to happen, or would have needed to be balanced by Z, and that you have to account for those outcomes—so with that prediction we can look for evidence for the joint operation of the whole geochemical system.”

Astrobiology and planetary habitability are key topics in space science. With the help of the JWST and other upcoming observatories and telescopes, scientists are getting a look at the atmospheres of distant exoplanets. But it’s a difficult process, made more difficult by our less-than-complete understanding of our own planet’s habitability. Understanding our own planet can help us better understand exoplanets.

But there’s a certain type of joy in understanding Earth for its own sake, and this new holistic approach should grow our understanding.

“We hope it’s a beautiful way to help understand all the chemistries that are involved in making Earth a safe place for life to evolve,” Blättler said.

“Overall, this work provides a systematic conceptual framework for understanding balance and imbalance in global biogeochemical cycles,” the authors conclude.

The post Earth’s Long-Term Habitability Relies on Chemical Cycles. How Can We Better Understand Them? appeared first on Universe Today.

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Once thrown away, disposable diapers and sanitary pads can take hundreds of years to decompose, because they contain plastics and other synthetic polymers. But now, researchers are replacing these materials with components made from protein biomass that is often discarded. They are sustainable and biodegradable, and they could potentially allow future diapers and pads to be flushed down a toilet or used as fertilizer.

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As you know, I go back and forth on the question of affirmative action for college and professional-school admissions, and even after I thought I’d settled on a view (i.e., give some preference to minorities among those equally qualified for admission), it still keeps changing. After I read the long New York Times piece below by the notorious Nikole Hannah-Jones, it’s changed a bit more, making me wonder if the Supreme Court, in banning race-based admissions, didn’t go a bit too far.

Although I’m not a huge fan of Ms. Hannah-Jones (I, along with many historians, thought the 1619 Project was based on a dubious thesis and was historically distorted, almost propagandistic), I have to say that I found the piece readable, engaging, and making some thoughtful points.  It’s also a good run-through of the history of black civil rights and attempts to secure equality since the Civil War: Plessy v. Ferguson, Brown v. Board of Education, Bakke v. California, all the way through the recent Harvard case.

I have not gone all the way over to Hannah-Jones’s views, set out below, but it’s clear that the question of affirmative action bears more thinking, at least for me. I’ve always thought that some form of reparations are due those who still suffer historically from oppression. My only question is what those reparations should be. It can’t be money, and in the end true reparations mean giving everyone, especially members of once-oppressed groups, equal opportunities from birth. That will of course take forever, so what do we do in the interim? Affirmative action has been the answer, and is still the answer for Hannah-Jones, but the Supreme Court has pretty much killed it.

At any rate, I’d read Hannah-Jones’s piece if you have time (click headline to read; I haven’t found it archived):

The topic is whether we should have a “colorblind” society, as was supposedly limned by Martin Luther King in his “I have a dream” speech. Hannah-Jones’s answer is no.  To achieve full equality in America, we must explicitly be aware of race, taking it into account when making employment or admissions decisions.  Clearly, she thinks that all the civil rights laws enacted since 1964 have done little to fix the problem of inequality.

Here are the main points I think she makes, as well as a few of my own comments.  Her quotes are in quotation marks.

1.) Descendants of American slaves have suffered a continual disadvantage since slavery was abolished, being segregated, denied equal rights, and in general subject to pervasive discrimination. The historical residuum of this discrimination is still with us, and I don’t think people can deny that.

2.) This problem needs to be made right by some form of reparations.  A color-blind society cannot make things right; we must have some form of affirmative action: preferential treatment of the descendants of slaves.

3.) A problem here: she wants only the descendants of slaves to get these advantages. Other blacks, like recent “immigrants and children of immigrants” from Africa and other places, are not entitled to these reparations.

4.) Other minority groups who have been subject to affirmative action, like Hispanics, aren’t dealt with in her article; in fact, the word “Hispanic” isn’t even given.  It is slavery, and slavery alone, that must be considered in affirmative action, which must apply only to those who can show they are descended from slaves. Yet other blacks and minorities also suffer, perhaps not for historical reasons but from race-based oppression itself. One has to consider the moral weight of this argument.

5.) Reparations cannot be based on socioeconomic status or “condition”; it must be based on ancestry tracing back to those who were enslaved, i.e.,  the “condition” of being a descendant of slaves.

6.) Increasing “diversity” is of little consequence. What Hannah-Jones wants is to increase the representation of descendants of slaves in American life through affirmative action. That must involve some kinds of quotas, not just a subjective method for increasing the proportion of black and brown faces in schools. Her stand thus explicitly opposes the Supreme Court’s Bakke decision, which ruled that there can be affirmative action so long as it increases diversity—seen as an innate good—but not if it involves quotas. Hannah-Smith doesn’t explicitly mention a need for quotas, but I think it’s inherent in her argument.

7.) Despite the “colorblindness” touted in King’s famous speech, he also made statements that could be interpreted as favoriting affirmative action (see below).

I’ll give some of her quotes that, to be sure, make points worth considering. Please comment below on the issue, the quotes, or the points above. I do recommend your reading her article. Even though it’s long, it’s well written.

The ramifications of the recent affirmative-action decision are clear — and they are not something so inconsequential as the complexion of elite colleges and the number of students of color who attend them: We are in the midst of a radical abandonment of a compact that the civil rights movement forged, a shared understanding that racial inequality is harmful to democracy.

. . . Race, we now believe, should not be used to harm or to advantage people, whether they are Black or white. But the belief in colorblindness in a society constructed on the codification of racial difference has always been aspirational. And so achieving it requires what can seem like a paradoxical approach: a demand that our nation pay attention to race in order, at some future point, to attain a just society. As Justice Thurgood Marshall said in a 1987 speech, “The ultimate goal is the creation of a colorblind society,” but “given the position from which America began, we still have a very long way to go.”

After Brown v. Board of Education (1954):

Civil rights activists were finally seeing their decades-long struggle paying off. But the architects and maintenance crew of racial caste understood a fundamental truth about the society they had built: Systems constructed and enforced over centuries to subjugate enslaved people and their descendants based on race no longer needed race-based laws to sustain them. Racial caste was so entrenched, so intertwined with American institutions, that without race-based counteraction, it would inevitably self-replicate.

And the Bakke vs. Board of Regents of the University of California case (1978), which rejected UC Davis’s use of racial quotas in its medical school, but allowed race to be used as one factor in admissions. Note how Hannah-Jones is concerned here exclusively with the descendants of slaves:

Thus, the first time the court took up the issue of affirmative action, it took away the policy’s power. The court determined that affirmative action could not be used to redress the legacy of racial discrimination that Black Americans experienced, or the current systemic inequality that they were still experiencing. Instead, it allowed that some consideration of a student’s racial background could stand for one reason only: to achieve desired “diversity” of the student body. Powell referred to Harvard’s affirmative-action program, which he said had expanded to include students from other disadvantaged backgrounds, such as those from low-income families. He quoted an example from the plan, which said: “The race of an applicant may tip the balance in his favor, just as geographic origin or a life spent on a farm may tip the balance in other candidates’ cases. A farm boy from Idaho can bring something to Harvard College that a Bostonian cannot offer. Similarly, a Black student can usually bring something that a white person cannot offer.”

But, of course, a (white) farm boy from Idaho did not descend from people who were enslaved, because they were farmers from Idaho. There were not two centuries of case law arguing over the inherent humanity and rights of farm boys from Idaho. There was no sector of the law, no constitutional provision, that enshrined farm boys from Idaho as property who could be bought and sold. Farm boys from Idaho had no need to engage in a decades-long movement to gain basic rights of citizenship, including the fundamental right to vote. Farm boys from Idaho had not, until just a decade earlier, been denied housing, jobs, the ability to sit on juries and access to the ballot. Farm boys from Idaho had not been forced to sue for the right to attend public schools and universities.

In Bakke, the court was legally — and ideologically — severing the link between race and condition. Race became nothing more than ancestry and a collection of superficial physical traits. The 14th Amendment was no longer about alleviating the extraordinary repercussions of slavery but about treating everyone the same regardless of their “skin color,” history or present condition. With a few strokes of his pen, Powell wiped this context away, and just like that, the experience of 350 years of slavery and Jim Crow was relegated to one thing: another box to check.

According to Hannah-Jones, Martin Luther King Jr. floated ideas similar to affirmative action (Reagan campaigned on a covertly racist platform):

Reagan, who had secretly called Black people monkeys and opposed the Civil Rights Act of 1964, opposed the establishment of the Martin Luther King Jr. federal holiday. Yet in the first commemoration of that holiday in 1986, he trotted out King’s words to condemn racial-justice policy. “We’re committed to a society in which all men and women have equal opportunities to succeed, and so we oppose the use of quotas,” he said. “We want a colorblind society, a society that, in the words of Dr. King, judges people not by the color of their skin but by the content of their character.”

This passage from King’s famous 1963 “I Have a Dream” speech has become a go-to for conservatives seeking to discredit efforts to address the pervasive disadvantages that Black Americans face. And it works so effectively because few Americans have read the entire speech, and even fewer have read any of the other speeches or writings in which King explicitly makes clear that colorblindness was a goal that could be reached only through race-conscious policy. Four years after giving his “Dream” speech, King wrote, “A society that has done something special against the Negro for hundreds of years must now do something special for him.” And during a 1968 sermon given less than a week before his assassination, King said that those who opposed programs to specifically help Black Americans overcome their disadvantage “never stop to realize that no other ethnic group has been a slave on American soil. The people who say this never stop to realize that the nation made the Black man’s color a stigma; but beyond this they never stop to realize that they owe a people who were kept in slavery 244 years.”

And, to finish, Hannah-Jones’s indication that we’re not where we want to be:

Today we have a society where constitutional colorblindness dictates that school segregation is unconstitutional, yet most Black students have never attended a majority-white school or had access to the same educational resources as white children. A society with a law prohibiting discrimination in housing and lending, and yet descendants of slavery remain the most residentially, educationally and economically segregated people in the country. A society where employment discrimination is illegal, and yet Black Americans are twice as likely to be unemployed as white Americans, even when they hold college degrees.

Now one could argue that equity should not be the goal if different groups have different abilities and preferences; instead he true goal should be equality of opportunity.  And I agree that we should aim for equality of opportunity rather than equality of representation. But the former will be nearly impossible to achieve given the resources needed. Perhaps one might hope that instead of trying to create equality of opportunity to  ensure equity, we should do the opposite: creating a bit more equity as a way of paving the way for equality of opportunity.

Weigh in below!

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