Whatever happened to the hole in the ozone layer? - Stephanie Honchell Smith

Prevodilac: Ivana Šimšić Lektor: Milenka Okuka

In the 1980s, the world faced a huge problem:

Osamdesetih godina prošlog veka, svet se suočavao sa ogromnim problemom:

there was a rapidly expanding hole in the ozone layer.

u ozonskom omotaču pojavila se rupa, koja se veoma brzo uvećavala.

So, what happened? And is it still there?

Pa, šta se desilo? I da li je i dalje tu?

Let’s go back to the beginning.

Vratimo se na početak.

The Sun makes life on Earth possible,

Sunce nam omogućava život na Zemlji,

but too much exposure to its UV radiation damages plant and animal DNA.

ali prekomerna izloženost UV zračenju oštećuje DNK biljaka i životinja.

Thankfully, about 98% of that radiation is absorbed by ozone molecules

Srećom, oko 98% tog zračenja upijaju molekuli ozona,

dispersed in the stratosphere,

raspršeni u stratosferi,

which are continuously broken apart and reformed in this process,

koji se stalno razlažu i ponovo spajaju u ovom procesu,

maintaining a delicate equilibrium.

održavajući osetljivu ravnotežu.

But in the early 1970s, two chemists— Mario Molina and Sherwood Rowland—

Ali ranih sedamdesetih, dvojica hemičara, Mario Molina i Šervud Rouland,

demonstrated that widely used chemicals called chlorofluorocarbons, or CFCs,

pokazali su da rasprostranjene hemikalije zvane hlorofluorougljenici ili CFC

could upset this balance.

mogu da poremete ovu ravnotežu.

CFCs were developed in the 1920s by three US-based corporations

CFC su 1920-ih razvile tri američke korporacije,

as coolants for refrigerators.

kako bi se koristili za rashlađivanje frižidera.

Unlike existing alternatives— such as ammonia or methyl chloride—

Za razliku od postojećih alternativa, amonijaka i metil hlorida—

CFCs were non-flammable and non-toxic—

CFC nisu bili zapaljivi, niti toksični—

meaning they wouldn't burst into flames or cause deadly gas leaks.

što znači da nisu mogli da gore, niti da izazovu smrtonosno curenje gasa.

They also made great propellants, foaming agents, and fire-retardants.

Takođe su bili sjajni kao gorivo, sredstvo za penušanje i usporivač plamena.

CFCs soon found their way into a variety of everyday items

CFC su se takođe našli u svakodnevnoj upotrebi

and became a multi-billion dollar per year industry.

i postali industrija vredna nekoliko milijardi na godišnjem nivou.

In the lower atmosphere, CFCs don’t break down or react with other molecules.

U nižem delu atmosfere, CFC se ne razlažu i ne reaguju sa drugim molekulima.

But Molina and Rowland showed that in the stratosphere,

Međutim, Molina i Rouland su pokazali da ih u stratosferi

they're broken apart by UV light, releasing chlorine atoms.

razlaže UV svetlost, ispuštajući atome hlora.

These then react with ozone,

Oni onda reaguju u dodiru sa ozonom,

destroying it faster than it can be replenished.

uništavajući ga brže nego što može da se oporavi.

A single chlorine atom can destroy thousands of ozone molecules

Jedan atom hlora može da uništi na hiljade molekula ozona,

before finally reacting with something else and forming a stable molecule.

pre nego što reaguje sa nečim drugim i formira stabilan molekul.

Seeing the threat to their bottom line,

Uvidevši da su im finansije u opasnosti,

CFC producers pushed back to discredit the scientists,

proizvođači CFC su se suprotstavili kako bi osporili rad naučnika,

even accusing them of working for the KGB.

optuživši ih čak za saradnju sa KGB-om.

Initial estimates showed that within 60 years,

Početna procena je pokazala da će za 60 godina

CFCs could reduce ozone concentrations by 7%.

CFC smanjiti koncentraciju ozona za sedam odsto.

But by 1985, it became clear that ozone depletion, especially over Antarctica,

Ali do 1985. godine, bilo je jasno da se oštećenje ozonskog omotača,

posebno iznad Antarktika, dešava mnogo brže.

was happening much faster.

Here, the extremely cold temperatures and unique structure of Antarctic clouds

Tamo su izuzetno hladne temperature i jedinstvena struktura oblaka

accelerated ozone loss.

ubrzale gubitak ozonskog omotača.

Scientists stationed in Antarctica noticed a massive drop

Naučnici stacionirani na Antarktiku, primetili su značajan pad

in overhead ozone occurring every spring.

u površinskom ozonu, koji se dešava svakog proleća.

Satellite data revealed the vast extent of these losses

Satelitski podaci su otkrili značajnu veličinu ovog gubitka,

and chemical tests confirmed that the cause was unquestionably CFCs.

a hemijski testovi su potvrdili da su CFC nesumljivo razlog za to.

NASA soon released visualizations, which were broadcast around the world

NASA je ubrzo objavila snimke koji su se emitovali širom sveta

and captured public attention.

i privukli pažnju javnosti.

If ozone depletion continued, rates of skin cancer would skyrocket.

Kada bi se nastavilo oštećenje ozonskog omotača, stopa raka kože bi naglo skočila.

Photosynthesis would be impaired, making plants—

Fotosinteza bi bila narušena, a biljke,

including rice, wheat, and corn—

poput pirinča, pšenice i kukuruza,

less productive and more susceptible to disease.

davale bi manje ploda i bile bi podložnije bolestima.

Global agricultural production would plummet,

Globalna poljoprivredna proizvodnja bi opala,

and entire ecosystems would collapse.

i čitavi ekosistemi bi se urušili.

But many politicians— weighing immediate economic concerns over long-term ones—

Mnogi političari su trenutne ekonomske razloge stavili ispred onih dugoročnih,

disagreed about what to do.

te se nisu složili šta da rade povodom ovoga.

The fight to ban CFCs found two unlikely allies

Borbu za zabranu CFC su podražala dva neočekivana saveznika,

in US President Ronald Reagan and UK Prime Minister Margaret Thatcher.

Ronald Regan, predsednik SAD-a i Margaret Tačer, premijerka V. Britanije.

Despite their general opposition to government regulation,

Uprkos tome što su uopšteno bili protivnici vladinih regulativa,

Reagan, who had undergone treatment for skin cancer,

Regan, koji se lečio od raka kože,

and Thatcher, who was trained as a chemist,

i Tačer, koja je bila i hemičarka,

recognized the need for immediate action.

uvideli su da treba preduzeti hitne korake.

The US and UK, along with Canada, Norway, Sweden, and Finland,

SAD i Velika Britanija, zajedno sa Kanadom, Norveškom, Švedskom i Finskom,

led calls for an international ban on CFCs.

pozvale su na međunarodnu zabranu CFC.

In 1987, representatives signed the Montreal Protocol,

Godine 1987, predstavnici su potpisali Montrealski protokol,

requiring the rapid phasing out of CFCs

zahtevajući brzo ukidanje CFC

and creating a fund to assist Global South countries

i osnivanje fonda kako bi se pomoglo zemljama globalnog juga

in obtaining affordable, non-ozone depleting alternatives.

da dobiju povoljne alternative, koje ne uništavaju ozonski omotač.

It was later ratified by every country on Earth—

Protokol je kasnije ratifikovan u svakoj zemlji na svetu,

the only treaty in history to achieve this.

što je bio jedini ovakav slučaj u istoriji.

In 1995, Molina, Rowland, and their Dutch colleague Paul Crutzen,

Godine 1995, Molina, Rouland i njihov holandski kolega Paul Krucen,

were jointly awarded the Nobel Prize in Chemistry.

zajedno su dobili Nobelovu nagradu za hemiju.

As the use of CFCs declined,

Kako je opadala upotreba CFC,

the ozone hole began shrinking,

tako je ozonska rupa počela da se smanjuje

and is predicted to disappear entirely by 2070.

i predviđa se da će potpuno nestati do 2070. godine.

But we’re not out of the woods yet.

Međutim, još uvek nismo van opasnosti.

While the ban was a win for the climate, as CFCs are potent greenhouse gases,

Iako je ova zabrana bila pobeda za klimu, pošto su CFC snažni gasovi staklene bašte,

the alternatives that replaced them— hydrofluorocarbons, or HFCs— are too.

alternative koje su ih zamenile— hidrofluorougljenici ili HFC nisu bolji.

While generally less potent than CFCs,

Iako su načelno slabiji od CFC,

HFCs still trap more heat than carbon dioxide

HFC i dalje zadržavaju više toplote od ugljen-dioksida

and are contributing to climate change.

i tako doprinose klimatskim promenama.

To address this, in 2016, the Kigali Amendment

Kako bi se ovo rešilo, 2016. godine je Kigali amandman

was added to the Montreal Protocol,

dodat u Montrealski protokol,

calling for an 85% cut in global HFCs by 2047.

zahtevajući smanjenje HFC od 85% na globalnom nivou do 2047. godine.

This alone could avoid up to 0.5°C of global warming by the end of the century.

Ovim bi moglo da se izbegne globalno zagrevanje od 0,5°C do kraja 21. veka.

Today, as we face the existential threat of climate change,

Danas, dok klimatske promene prete našem opstanku,

the Montreal Protocol serves as a model for the decisive global cooperation

Montrealski protokol služi kao model odlučujuće globalne saradnje,

we need to combat it.

kojom treba da ih pobedimo.

The question is, what will it take for us to come together again?

Ostaje pitanje, šta je potrebno da bismo se ponovo udružili?