Ekologija

Истраживање групе међународних научника под називом „Нема доказа о глобално кохерентним топлим и хладним периодима у прединдустријској заједничкој ери“ показује да је тренутна стопа загревања виша од било које друге посматране у последњих 2000 година.

Тим предвођен др Рафаелом Нојкомом са швајцарског универзитета у Берну каже да њихово истраживање показује да су аргументи тзв. климатских скептика, односно оних који не верују у постојање климатских промена, „на стакленим ногама“. Тако актуелне климатске промене нису део обрасца, већ својеврсни преседан у климатској историји Земље.

Наиме, проучавајући климатску историју планете Земље, установљено је неколико кључних ера. Једна од њих је римски топли период, који је трајао од 250. до 400. године нове ере и који карактерише неуобичајено висока температура. Сушта супротност је мало ледено доба, са веома ниском температуром од 1300. године надаље.

Неки, попут климатских скептика, стога тврде да се Земља током векова хладила и загревала неколико пута и да је загревање, које је започело након Индустријске револуције, само део истог обрасца, те да нема разлога за бригу.

Нојкомов тим сада каже да овај аргумент више дефинитивно не стоји. Они су реконструисали климатске услове који су постојали током 2000 година користећи 700 записа о променама температуре. Тако су установили да се ниједан од већих климатских догађаја, попут малог леденог доба или средњовековног топлог периода, није десио на глобалном нивоу. Тако је, рецимо, први био најјачи на Пацифику у 15. веку, а у Европи тек два века касније. Током другог, средњевековног топлог периода, који је трајао од 950. до 1250. године, значајно висока температура задесила је тек 40 % Земљине површине.

Данашње загревање, међутим, озбиљно погађа велику већину Земљине лопте.

„Установили смо да се најтоплији период у протекла два миленијума десио у 20. веку, и да је захватио више од 98 % Земље“, стоји у студији, коју чине три повезана истраживања.

„Ово пружа чврсте доказе да је антропогено (људски изазвано) глобално загревање не само неупоредиво ни са једним периодом у смислу апсолутних температура, већ и без преседана у просторној конзистентности у протеклих 2000 година.“

Истраживачи су такође приметили да су пре модерног индустријског доба највећи утицај на климу имали вулкани. Нису утврдили никакве индикације да су варијације Сунчевог зрачења утицале на средњу глобалну температуру. Актуелни период, тврди тим, знатно премашује природну варијабилност.

„Из инструменталних података и из наше реконструкције видимо да у недавној прошлости стопа загревања очигледно премашује стопе природног загревања које смо израчунали – то је још један поглед на ванредну природу садашњег загревања“, каже др Нојком.

Иако се његов тим није бавио доказивањем да је човек највише утицао, и да највише утиче, на садашње климатско стање, резултати студије показују да је то, ипак, случај.

„Ми се нисмо фокусирали да сазнамо шта изазива најскорије загревање јер таквих студија има много и оне увек показују  да је узрок антропоген“, додаје др Нојком.

„Ми то нисмо експлицитно тестирали… подаци које имамо показују да природни узроци нису довољни да изазову просторни образац и стопу загревања којој сада сведочимо“, закључује др Нојком.

Према подацима Дечјег фонда Уједињених нација, УНИЦЕФ-а, данас скоро 800 милиона људи широм света нема приступ пијаћој води. Њих 800 милиона – што је сваки десети човек на планети Земљи – заједно проведу чак 200 милиона сати дневно одлазећи по воду до удаљених извора. Иако постоје начини да се контаминирана вода очисти, а из морске одстрани со, ове технологије су често скупе, неприступачне и захтевају превише енергије и времена, због чега су ван домашаја многих заједница.


Стога и не чуди да у последње време истраживачи широм света покушавају да створе другачију алтернативу милионима који немају воду за пиће. Један од успешнијих покушаја представљају и велики уређаји који личе на резервоаре (solar stills) и који користе енергију сунца да прљава или слана вода испари, а потом кондензују пару у безбедну, пијаћу воду. Међутим, овакви резервоари могу да произведу довољно воде тек за једну малу породицу. Зато су истраживачи са Универзитета у Тексасу, који се годинама баве овим проблемом, пронашли бољи начин – резервоару су додали нови материјал који убрзава процес евапоризације, и тиме ствара сву неопходну воду за једно просечно домаћинство. Тим из Остина се сада нада да ће се њихово решење показати као ефикасно и јефтино, чиме ће, како тврде, успети да помогну милионима сиромашних широм света.


Наиме, „традиционални“ соларни резервоар је попут посуде са црним дном која је напуњена водом и обложена чистим стаклом или пластиком. Црно дно посуде апсорбује сунчеву светлост и загрева воду тако да она испарава, остављајући за собом загађиваче, односно прљавштину. Водена пара се затим кондензује и улази у колектор. Међутим, главни недостатак ове методе јесте мала количина прерађене воде: комерцијалне верзије овог резервоара производе 0,3 литара воде на сат по једном квадратном метру површине прекривене водом. Једној особи је у просеку потребно три литра пијаће воде на дан. Како би једна мања породица имала довољно пијаће воде, потребан је резервоар величине отприлике пет квадратних метара.


Да би побољшао крајњи производ, тим са Универзитета у Тексасу је направио посебан хидрогел користећи смеше полимера које формирају 3Д порозну мрежу која упија воду. Потом су направили сунђер који подсећа на гел, користећи два полимера (PVA и PPy) и ставили их на површину воде у соларном резервоару. На овај начин добили 3,2 литара воде, а у намери да добију више, следећи пут су направили још бољи хидрогел: претходној смеши додали су још један полимер, хитосан, који јако привлачи воду. Соларни резервоар је сада, користећи нови хидрогел, дестиловао 3,6 литара воде на сат по метру квадратном, што је највећа стопа пречишћавања воде досад постигнута и око 12 пута већа количина од данашњих комерцијално доступних верзија.

https://bostonreview.net/science-nature/geoff-mann-it-was-not-supposed-end-way

...

There are at least two closely related ways in which the idea of the Anthropocene signals the anxious unsettledness of liberalism. The first brings us back to the “we” named by its implied “humanity.” This is a “we” without a “they.” This is the regulative ideal of modern liberal discourse, which remains dominant in the global North. It refuses outright the “realist,” zero-sum conception of politics associated with someone like Henry Kissinger, or the jurist Carl Schmitt, for whom the defining moment in politics is the distinction between friend and enemy. The very idea of the Anthropocene—like, say, multilateralism, multiculturalism, or cosmopolitanism—posits a collective subject without an enemy: a “we” whose self-declared openness and inclusivity makes it an impossible object of enmity, or even of critique.

There are of course very powerful criticisms of these universalizing liberal categories: the “public interest,” for example, is usually the interest of a specific fraction of the public; the “international community” obscures geopolitical hegemony and conflict, and “human rights” are very unevenly distributed across a hierarchy of humanity. The “solidarity” performed by these categories is a false solidarity, and that of the Anthropocene’s “humanity,” implicated in a so-called “global collective action problem,” is an equally false solidarity.

But the inaccurate and, indeed, basically history-less and geography-less “we” interpellated by the Anthropocene is only part of the point. The second way the idea of the Anthropocene signals liberalism’s fading confidence arises from the fact that it represents a desperate attempt to rescue a rule of temporality with a narrative device that cannot help but undermine that rule as soon as it is introduced. A recent paper in Ecology and Society, for instance, calls the Anthropocene a “game changer”:

    Debates and analytical frameworks for considering how to secure a ‘good life’ for people today and in the future have proliferated in recent literature, as are discussions about altering the unsustainable trajectory of human activity that earned the label Anthropocene in the first place. The concept has highlighted a growing sense of urgency; we need to better understand the processes of transformation and innovation and marry that knowledge with our growing understanding of complex social-ecological interactions to build the capacity to both respond to new disturbances and risks and to move toward sustainable pathways.

I want to emphasize how difficult it is to imagine the Anthropocene as a moment in any humanist metanarrative saturated in the “good life.” The political-economic organization of the global capitalist North is the most devastating for life on Earth. This is where the whole problem originates and where the most radical changes must take place. And yet, the specifically liberal narrative that names freedom and justice as essential ingredients to the “good life”—the story that many of these privileged residents tell themselves—is one of the most fundamental obstacles to change.

This is because rather than confronting past and contemporary unfreedom, injustice, and ecological devastation in their actual, often quite purposeful operation, the metaphysics of liberalism engages them as unfortunate historical mistakes. It thus attaches to catastrophe the status of anomaly. This is, for example, the mundane response to phenomena labelled “market failures,” which signal “temporary” mismatches between actually existing capitalism and the idealism of liberalism’s unfolding conceptual self-measure. As if markets usually did things just right, and these were exceptions.

...

If spiraling political economic inequality, the disintegration of democracy (however nominal), and the rise of macho racist nationalism did not seem challenging enough, climate change alone promises a red alert that is unlikely ever to turn off. “Progress” is not one of the things we expect the Anthropocene to inaugurate. One might even go so far as to say that if the Anthropocene has a plot, it is usually presumed to be tragic. Insofar as it has a place in the metanarrative it is, I think, widely understood as potentially the final act in the “human drama.” It sometimes seems as if our purpose, now, as actors in that staging, is simply to delay the curtain call as long as possible. We are in a transition during which “adaptation” supplants “progress” as the telos of the age.

This has potentially devastating implications not only for the liberal metanarrative, but for liberalism more broadly, at least partly because it seriously destabilizes its capacity to provide its proponents, or anyone else, with some sort of useful historical and geographical orientation. Growth, progress, consensus, reason, reasonableness, equilibrium: none of this can be depended upon at present. Even liberalism’s conception of what it means for something to go wrong, the promised finitude of the moment of crisis, does not work anymore. If we prod at these cracks proliferating in liberal ideology and institutions—cracks from which the Anthropocene emerged—we also find ourselves challenging concepts like “risk” and “uncertainty” which we use to help ready ourselves for the future.

All of which is to say that the reality management system by which history is assembled for Spaceship Earth’s most privileged passengers has failed, and those passengers do not know what to think or do because the categories that are supposed to make sense of experience are increasingly inadequate. The tragedy of liberalism is its inability to narrate the end of progress. Yet this is the impossible task asked of the Anthropocene.

...

The tragedy of politics at the heart of liberal thinking, then, is that the world requires violence. It is a world of progress, but also a world of scarcity, in which someone must bear the burden of life’s necessity, so that the historical work of freedom and justice can continue. Since no one would willingly bear this burden, the violence that grounds politics is inevitable. This is the liberal tragedy, as its most incisive advocates have understood.

In other words, if a tragic sensibility is tempting, even logical at this moment in time, it does not mark a break with liberalism. On the contrary, it is part of how liberalism has managed the tragedies it has wrought. As Canadian Prime Minister Pierre Trudeau put it many years ago when confronted again and again with the historical devastation of Indigenous peoples by liberal capitalist Canada: “We must forget many things if we want to live together. . . . What can we do to redeem the past?”

But the temporal posture of the Anthropocene, however we date its origin, is futural, and the future is not something we can redeem, nor is it something one can forget. Instead, we anxiously await what the Anthropocene will bring. We have crossed the threshold of a new age, and now, we wonder, what will happen next? Or, more precisely, since we have a pretty good sense of what will happen next, what we wonder is “when will it happen, and who will it happen to?” Who will bear the burden of necessity?

This is the way in which the Anthropocene realizes its failure. Constructed in an attempt to rationalize—in the Weberian sense—the present as the next stage in liberal modernity, it unintentionally announces its demise in crises no one can promise will end. Inaugurated at least partially to communicate the solidarity of humanity on “our” fragile Spaceship Earth, it unwittingly exposes the uneven violence of the distribution of life’s burdens across human communities, communities whose “unity” is a product of the ascriptive inclusion that is the only way the powerful can fool or convince ourselves that the burdens are collectively born.

...

We are not doomed. But just as there is not a universal “we,” there is not just one way forward either. Contrary to liberal conceptions of history, the end of liberalism is not the end of the world.

Instead, the arrival of the Anthropocene—and its role in revealing the shaky foundations of liberalism— might allow other histories and futures that have been yoked to liberalism by a set of practices and promises to provide their subjects (and perhaps “us”) with potentials that we cannot yet see. Those others are, for the most part, greatly impoverished by their contact with liberalism and its siblings, capitalism and colonialism. They will need time to ask their own questions of the future, to which the Anthropocene is very unlikely to be the answer, and to identify the true uncertainties that liberalism seems to have foreclosed.

Could One Man Single-Handedly Ruin the Planet?

By David Wallace-Wells  
   
An aerial view of Amazon rainforest deforestation, with trees being burned for farm management. Photo: Ricardo Funari/Brazil Photos/LightRocket via Getty Images

...
But Brazil’s newly elected president just might test the proposition that no individual matters all that much to the climate. Often called the “Trump of the Tropics,” the cartoonish quasi-fascist Jair Bolsonaro is almost certain to be worse on global warming than Trump himself. So bad, in fact, that he is already a horrifying argument for a Great Man Theory of climate change.
...

For starters, the plan to open up the Amazon would mean Brazil has absolutely no chance of meeting its Paris commitments. A group of Brazilian scientists has estimated that between 2021 and 2030, Bolsonaro’s deforestation would release the equivalent of 13.12 gigatons of carbon. Last year, the United States emitted about five gigatons. This means that this one policy would have between two and three times the annual carbon impact of the entire American economy, with all of its airplanes and automobiles and coal plants. The world’s worst emitter, by far, is China; the country was responsible for 9.1 gigatons of emissions in 2017. This means Bolsonaro’s policy is the equivalent of adding, if just for a year, a whole second China to the planet’s fossil-fuel problem — and, on top of that, a whole second United States. This is not a climate that can tolerate another China; according to the U.N.’s recent IPCC report, we may not even be able to tolerate the one we have for 12 more years. Bolsanaro’s single policy would fully eat up 20 percent of a stable climate’s total remaining carbon budget. As Emily Atkin put it at The New Republic, “The livability of the entire planet is at stake.”

But the problem is bigger than that extra carbon, believe it or not. The Amazon, alone, produces 20 percent of the world’s oxygen. A smaller, degraded rainforest won’t threaten our breathing air — there is just way too much oxygen around for us to ever worry about that. But the figure does signal just how prolific the Amazon is as a photosynthesizing force, which is critical because it produces all that oxygen out of carbon, which it sucks out of the air. And not just a little: The trees of the Amazon take in a quarter of all the carbon absorbed by the planet’s land each year. This is what makes it what scientists call a “carbon sink,” taking in large stores of CO2 that would otherwise be warming the planet even more drastically.

This is the forever problem of deforestation. Every tree cut in Bolsonaro’s denuded Amazon would release its carbon in a one-time burst, but the rainforest left behind would be smaller, which means it would be less capable of absorbing carbon. But the effect doesn’t just zero out; ultimately, it reverses. For years, scientists have worried that the world’s forests would flip from carbon sinks to carbon sources — become net producers of carbon rather than net absorbers. In fact, this is one of the feedback loops they most worry about: the planet’s not just losing one of its largest natural resources in mitigating the extreme possibilities of global warming, but having that resource turn against it, almost like a climate traitor, suddenly working on behalf of the most dire scenarios.
...

A new study this week from the World Wildlife Federation found that, globally, wildlife populations have declined by 60 percent since just 1970, at rates 1,000 times faster than at any previous point in planetary history — a discovery the WWF director general Marco Lambertini called “mind-blowing.” The UK chief executive put the news in somewhat more eye-opening perspective: “We are the first generation to know we are destroying our planet and the last one that can do anything about it.”
...


https://nymag.com/intelligencer/2018/10/bolsanaros-amazon-deforestation-accelerates-climate-change.html

Meanwhile, US space agency Nasa said that overall fire activity in the Amazon basin was slightly below average this year.

The National Institute for Space Research (Inpe) said its satellite data showed an 84% increase on the same period in 2018.

...
The Amazon is a vast, ineffable, vital, living wonder. It does not, however, supply the planet with 20 percent of its oxygen.

As the biochemist Nick Lane wrote in his 2003 book Oxygen, “Even the most foolhardy destruction of world forests could hardly dint our oxygen supply, though in other respects such short-sighted idiocy is an unspeakable tragedy.”

The Amazon produces about 6 percent of the oxygen currently being made by photosynthetic organisms alive on the planet today. But surprisingly, this is not where most of our oxygen comes from. In fact, from a broader Earth-system perspective, in which the biosphere not only creates but also consumes free oxygen, the Amazon’s contribution to our planet’s unusual abundance of the stuff is more or less zero. This is not a pedantic detail. Geology provides a strange picture of how the world works that helps illuminate just how bizarre and unprecedented the ongoing human experiment on the planet really is. Contrary to almost every popular account, Earth maintains an unusual surfeit of free oxygen—an incredibly reactive gas that does not want to be in the atmosphere—largely due not to living, breathing trees, but to the existence, underground, of fossil fuels.
...

“What would happen if we combusted every living cell on Earth?” it asked. That is, Peters wanted to know what would happen to the atmosphere if you burned down not just the Amazon, but every forest on Earth, every blade of grass, every moss and lichen-spackled patch of rock, all the flowers and bees, all the orchids and hummingbirds, all the phytoplankton, zooplankton, whales, starfish, bacteria, giraffes, hyraxes, coatimundis, oarfish, albatrosses, mushrooms, placozoans—all of it, besides the humans.

Peters pulled up the next slide. After this unthinkable planetary immolation, the concentration of oxygen in the atmosphere dropped from 20.9 percent to 20.4 percent. CO2 rose from 400 parts per million to 900—less, even, than it does in the worst-case scenarios for fossil-fuel emissions by 2100. By burning every living thing on Earth.

“Virtually no change,” he said. “Generations of humans would live out their lives, breathing the air around them, probably struggling to find food, but not worried about their next breath.”

...

“The notion that we owe the breath we breathe to the rain forest, or the [phytoplankton] off the rain forests’ coasts, is just a little bit misinformed on the long timescale,” says Peters.

You don’t get to 20.9 percent, or an atmosphere that can host animal life, without geologic time, and without the fossil record. The tiny remainder of photosynthetic stuff that isn’t consumed and respired again by life—that 0.01 percent of plants and phytoplankton that manages to escape from this cycle of creation and destruction—is responsible for the existence of complex life on Earth. It’s the organic carbon that, once created, doesn’t get consumed again. Somehow this rounding error of plant stuff gets shuttled away after it dies, and is shielded from decomposition before it can be undone by the oxygen it produced in life. By not getting destroyed by oxygen, this conserved plant stuff gifts a tiny surplus of the unused gas to the atmosphere above. On the time scale of tens of millions of years, such meager gifts can accumulate—apparently to 20.9 percent.

...

In other words, we have been gifted such an absurd surplus of oxygen by deep geological time, and by strange ancient life we’ll never know, that it won’t soon run out by our own hand, whether by deforestation or industry. Thankfully, most of the organic carbon in the Earth can be found not in easily recoverable reservoirs of fossil fuels, available to feed our industrial appetites, but in rather more rarefied deposits—small whispers of this life diffused in mudstones throughout Earth’s crust. There’s plenty of oxygen. For now.
...

https://www.theatlantic.com/science/archive/2019/08/amazon-fire-earth-has-plenty-oxygen/596923/

--- wrote:A frequent visitor to South America, Sabaj explains that loggers looking to extract timber from the rainforest will clear secondary roads that run perpendicular to the Trans Amazonica Highway. After the large valuable trees are removed, fires are used to clear the remaining brush, creating open pasture for cattle.
“The scattered trees that escape logging are often killed by the fires but remain standing as lonely tombstones of the deceased rainforest,” said Sabaj. “In Pará state over 8,761 fires have been recorded for this August, which is well above last year’s August (2,782), but well below the record high of 23,635 set in August 2005.”
“In fact, deforestation from fires in the first weeks of August, the start of the dry season, is more than 80% higher than over the same period last year,” explains Richard McCourt, PhD, associate curator of botany at the Academy of Natural Sciences and professor in the College of Arts and Sciences. In an opinion piece for The Philadelphia Inquirer, McCourt said it is unknown and untold the numbers of species of trees, insects, frogs and birds losing their homes and perishing in the flames.

Džejson Uekstin wrote:“One huge problem with this is that although the entire Amazon Basin is not burning, the biodiversity in the basin is not uniform, meaning there are distinct areas of endemism that have unique assemblages of species and some of these unique areas are being heavily hit by agricultural practices and these fires,” said Jason Weckstein, PhD, associate curator of ornithology at the Academy of Natural Sciences and associate professor in the College of Arts and Sciences.

Gargantua wrote:You don’t get to 20.9 percent, or an atmosphere that can host animal life, without geologic time, and without the fossil record.