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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 CO2
into the atmosphere. Excess CO2 prevents heat from escaping,
instead trapping it in and raising the temperature of Earth.
Ideally humans exhale CO2 which plants need. Plants give off
oxygen as a waste product of photosynthesis, and humans inhale
that oxygen. This cycle helps keep the CO2 concentration in the
atmosphere fairly steady.
However, humans engage in activities that let off much more CO2
than plants could ever use up. This excess CO2 is added to the
atmosphere.
The three most abundant sources of this excess of CO2 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
•Sun’s 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 doesn’t 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 hadn’t received snow in almost a century
gathered snowflakes on their streets.
*Glaciers are shrinking!... But some are getting bigger. GW
attackers say we don’t know enough about icebergs to explain
this, so we shouldn’t link it to global warming.
*The Earth’s temperature is getting warmer!...wrong again, it’s
getting colder.
*Politics have skewed information.
*Earth’s climate was even hotter than it is now centuries ago –
we aren’t looking at the “big picture.”