Living Earth Extra Reading 10/19/2012
*The basics: a brief introduction to climate change
global air temperatures are already 1.4 degrees higher than they were at the start of the 20th century, and
have risen about 1.1 degree F over just the last 30 years
Intergovernmental Panel on Climate Change (IPCC), average global temperatures are likely to rise by
another 2 to 11.5 degrees F by 2100
What is the difference between weather and climate?
“Climate is what you expect; weather is what you get.”
What is global warming?
Humans are creating climate change by burning large amounts of fossil fuels — coal, oil, natural gas.
Another factor is deforestation; when forests are cut down or burned, they can no longer store carbon, and
the carbon is released to the atmosphere. The gases, especially CO2, act like a blanket and restrict the rate
at which Earth’s surface can radiate heat to space. The result is global warming
Where will the impact be greatest?
greatest impact toward the North Pole and the least increase toward the South Pole and in the tropics. As
an example of what may be in store, New England’s temperature is projected to increase by 6 to 10 degrees
F by 2100, in which case Boston’s climate would resemble that of Charlotte, North Carolina (a 6 degree
increase) or Atlanta, Georgia (a 10 degree increase).
How does water heat and cool our climate?
Water molecules also heat the atmosphere directly by absorbing sunlight. Even though the amount of water
in the atmosphere at any one time is relatively small, air contains enough water molecules to absorb about
70% of incoming sunlight, thereby warming the atmosphere.
What is the greenhouse effect?
molecules of trace gases, especially water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous
oxide (N2O) and ozone (03) that strongly absorb infrared radiation contained in sunlight, or emitted by land
and water as they cool.
water vapor and trace gases keep Earth about 54º F warmer than it would be without them. This retention
of heat is called the greenhouse effect and the gases that cause it are known as greenhouse gases.
What are Fossil Fuels?
the carbonrich remains of terrestrial plants (coal), marine phytoplankton and zooplankton (oil), or natural
gas (methane) that has been buried and compressed under sediments for millions of years. Burning fossil
fuels that have been mined from deep in the earth or seabed returns ancient fossil carbon as new CO2 to
the atmosphere from the earth where they had been out of circulation
large amounts of methane have been generated by anaerobic digestion of wastes at sewage treatment
plants, dumps and stockyards as well as by cattle.
How fast has greenhouse gas emissions grown in recent years? Human emissions of greenhouse gases have increased 70% between 1970 and 2004, accord