Zašto se Zemlja zagrijava? Zamislimo Zemlju samo na trenutak kao staklenik. Svake sekunde ogromna količina energije upada u naš staklenik. Naša atmosfera, stakleni krov i zidovi, odražava dio te energije, ali većina prođe pravo i sve zagrije. Veći dio te toplote koristi se za bijeg natrag u svemir, održavajući nas na stabilnoj, toploj temperaturi.
Why is the world warming up? Let's think of Earth for just a moment as a greenhouse. Every second, a huge amount of energy smashes into our greenhouse. Our atmosphere, the glass roof and walls, reflects some of that energy, but most of it passes right through and heats everything up. Much of that heat used to escape back into space, keeping us at a stable, warm temperature.
Ali onda se nešto promijenilo. Ljudi su počeli izbacivati dovoljno ugljičnog dioksida da svakodnevno pune milijarde staklenika. Šta radi sav taj staklenički plin? Čini staklo našeg staklenika debljim. Deblje staklo znači da toplota izlazi u svemir mnogo sporije. I ne zaboravite, energija sunca još uvijek se emitira jednako brzo kao i prije. Rezultat je planeta s temperaturama prevrućim za naše želje i, na kraju... život.
But then something changed. Humans began to spew enough carbon dioxide to fill billions of greenhouses each day. What does all that greenhouse gas do? It makes the glass of our greenhouse thicker. Thicker glass means heat escapes into space much more slowly. And don't forget, energy from the sun is still streaming in just as quickly as before. The result is a planet with temperatures too hot for our liking and, eventually... living.
[Odbrojavanje Preduzmite akciju u vezi s klimatskim promjenama na Countdown.ted.com]
[Countdown Take action on climate change at Countdown.ted.com]