Presentation on theme: "Definition: An increase in Earth's mean global temperature. Problem: Hotter… and hotter… and even hotter. How will life on Earth survive extreme temperatures?"— Presentation transcript:
Definition: An increase in Earth's mean global temperature. Problem: Hotter… and hotter… and even hotter. How will life on Earth survive extreme temperatures?
Basically the problem is that humans are releasing TONS of CO 2 into the atmosphere. Excess CO 2 prevents heat from escaping, instead trapping it in and raising the temperature of Earth. Ideally humans exhale CO 2 which plants need. Plants give off oxygen as a waste product of photosynthesis, and humans inhale that oxygen. This cycle helps keep the CO 2 concentration in the atmosphere fairly steady. However, humans engage in activities that let off much more CO 2 than plants could ever use up. This excess CO 2 is added to the atmosphere. The three most abundant sources of this excess of CO 2 are the burning of fossil fuels, cement making, and deforestation.
Yellow lines – heat from sun Blue lines – heat leaves to outer space Orange lines – heat returned to Earth b/c of atmosphere Suns rays blocked = freezing Atmosphere keeps in too much heat = heated
*Ray 1 – absorbed by air *Ray 2 – absorbed by ground to some to space *Ray 3 – reflects from ground to space *Ray 4 – reflects to space by atmosphere
Is the globe really warming? Many scientists believe global warming doesnt exist and that people are worrying for no reason. GW supporters said that 2007 would be one of the hottest years on Earth. It was actually one of the coldest years. Many places that hadnt received snow in almost a century gathered snowflakes on their streets.
*Glaciers are shrinking!... But some are getting bigger. GW attackers say we dont know enough about icebergs to explain this, so we shouldnt link it to global warming. *The Earths temperature is getting warmer!...wrong again, its getting colder. *Politics have skewed information. *Earths climate was even hotter than it is now centuries ago – we arent looking at the big picture.