Transcript for Global warming 101

For 2.5 million years

the Earth's climate has fluctuated

cycling from ice ages to warmer periods.

But in the last century the planet's temperature has risen unusually fast

about 1.2 to 1.4 degrees Fahrenheit

Scientists believe it's human activity

that's driving the temperatures up

a process known as 'global warming'.

Ever since the industrial revolution began

factories, power plants and eventually cars have burned

fossile fuels such as oil and coal

releasing huge amounts of carbon dioxide

and other gases into the atmosphere.

These greenhouse gases trap heat near the Earth

through a naturally ocurring process

called 'The greenhouse effect'

The Greenhouse effect begins with the sun

and the energy it radiates to the Earth

The Earth and the atmosphere absorb some of this energy

while the rest is radiated back into space

Naturally occurring gases in the atmosphere

trap some of this energy

and reflect it back

warming the Earth

Scientists now believe

that the greenhouse effect is being intensified

by the extra greenhouse gases that humans have released

Evidence for global warming includes

a recent strain of very warm years

Scientists record that 1998

was the warmest year in measured history

with 2005 coming in second

Meanwhile, readings taken from ice core show

that the greenhouse gases, carbon dioxide and methane

have hit their highest levels in the past 420,000 years.

Arctic sea ice is also shrinking

According to NASA studies,

the extent of Artic sea ice has declined

about 10 %

in the last thirty years

As long as industrialized nations

consume energy

and developing countries increase

their fossile fuel consumption

the concentration of greenhouse gases in the atmosphere

will continue to rise

Researchers predict

that temperatures will increase about 2 to 10 degrees Fahrenheit

by the end of the century

what’s lesser in

what rising temperatures mean for the planet

Some climate models predict

subtle changes

Others forecast rising sea levels

which could flood coastal areas around the world.

Weather patterns could change

making hurricanes more frequent

Severe droughts could become more common in warm areas

and species unable to adapt to the changing conditions

would face extinction

Although much remains to be learned about global warming

many organizations advocate cutting greenhouse gas emissions

to reduce the impact of global warming

Consumers can help

by saving energy around the house

switching to compact fluorescent light bulbs

and driving fewer miles in the car each week

These simple changes may help

keep the Earth cooler in the future