Should the U.S. swap Iranians held in U.S. prisons for the three U.S. hikers held in Iran?

Continue reading this entry ...

7

60

Should Punxsutawney Phil be replaced by a robot?

Continue reading this entry ...

21

122

Should tigers or other endangered wildlife be rented out in order to raise funds to protect species?

Continue reading this entry ...

4

44

Do the health benefits from tougher smog rules outweigh the financial costs?

Continue reading this entry ...

3

38

Should clean energy outweigh cultural and aesthetic concerns when it comes to the proposed Cape Cod wind farm?

Continue reading this entry ...

6

25

Does spreading public details of pending crime sweeps cross a legal line?

Continue reading this entry ...

1

14

How would you describe 2009 for you and your family?

Continue reading this entry ...

16

141

Magma

Molten rock could be melting parts of the ice sheets that cover Antarctica and Greenland. In northeast Greenland, scientists have discovered a thin spot in the Earth's crust where heat from magma could be responsible for a stream flowing aboveground.

Continue reading this entry ...

0

0

Fossil fuels

In the U.S., coal-fired power plants are the largest source of carbon dioxide from the burning of fossil fuels. Transportation is the second-lrgest overall source.

Continue reading this entry ...

0

0

Logging

In Brazil, deforestation is a major source of CO2 emissions. The Trans-Amazonian highway brought with it logging as it opened up the Amazon to cattle ranches and farming.

Continue reading this entry ...

0

0

Should climbers be required to take locator beacons with them?

Continue reading this entry ...

7

58

Population growth

Climate experts have been slow to make a connection, in part because population has been more of a health issue. But The Lancet, an influential British medical journal, in September 2009 urged the health and climate fields to take this connection seriously.

Continue reading this entry ...

0

0

Urban heat islands

Asphalt, concrete, and other building materials in urban areas absorb more solar radiation by day than do rural areas with green vegetation. At night, much of that urban heat is released, creating a warm bubble that can be as much as 2 to 5 F higher than surrounding rural areas.

Continue reading this entry ...

0

0

Temperatures

This decade is on track to become the warmest since records began in 1850, and 2009 could rank among the top-five warmest years, the U.N. weather agency says.

Continue reading this entry ...

0

0

Carbon dioxide

Greenhouse gases like carbon dioxide have made Earth livable by trapping heat from the sun. But emissions of these gases have accelerated due to the burning of fossil fuels and forests, trapping even more heat. The world today emits 29 percent more carbon dioxide than in 2000.

Continue reading this entry ...

0

0

Methane

The second-most abundant, man-released greenhouse gas after carbon dioxide, albeit a distant second, methane is 20 times more effective in trapping heat than CO2. Manmade sources include landfills, natural gas and petroleum systems, livestock and coal mining.

Continue reading this entry ...

0

0

Nitrous oxide

The third-most common greenhouse gas, it makes up about 6 percent of all emissions. Manmade sources include farming and livestock, burning of fossil fuel and sewage treatment. Research has found that thawing permafrost and drying bogs also release nitrous oxide and methane.

Continue reading this entry ...

0

0

Water vapor

NASA satellite data show that Earth's most abundant heat-trapping greenhouse gas is concentrated in the tropics and that water vapor is increasing as temperatures rise. But its role doesn't end there.

Continue reading this entry ...

0

0

Arctic sea ice

The amount of summer sea ice in 2009 was the third-lowest level since the start of satellite records in 1979. Only 2007 and 2008 amounts were smaller.

Continue reading this entry ...

0

0

Ice sheets

Melt streams are becoming more common on Greenland's ice sheet during summer. The ice sheet along the coast, as well as coastal areas of western Antarctica, have seen significant melt. Antarctica's eastern ice sheet had been more stable but also shows signs of a decline.

Continue reading this entry ...

0

0

Glaciers

Overall, mountains are losing more glacial mass than they are adding. Glaciers are shrinking three times faster than in the 1970s and the average glacier has lost 25 feet of ice since 1997, according to the World Glacier Monitoring Service at the University of Zurich.

Continue reading this entry ...

0

0

Sea level

In the last century, seas have risen about 8 inches. Some of that is thermal expansion from warming waters, and some is from ice sheet and glacial melt.

Continue reading this entry ...

0

0

Coral reefs

Bleaching, diseases and acidification are the biggest threats to these crucial marine ecosystems. Bleaching can occur when sea temperatures rise just a few degrees above the average of the warmest summer months where coral reefs live.

Continue reading this entry ...

0

0

Species extinction

Some animals and plants are better than others at adapting to climate change. Audubon says data from the past 40 years shows half of the 305 widespread bird species that winter in North America have shifted significantly north since 1968, some by hundreds of miles.

Continue reading this entry ...

0

0

Thermohaline circulation

Often called the ocean's "conveyor belt," this system impacts all seas. In the Atlantic Ocean, it circulates water into the North Atlantic, where the water cools and then sinks at high latitudes.

Continue reading this entry ...

0

0