August 19, 2015

On Tuesday, August 18, U. S. President Barack Obama outlined a plan to cut methane gas emissions from oil and natural gas drilling. The plan calls on petroleum companies to  capture much of the methane produced when they drill new wells. Currently, some of this methane gets released into the atmosphere. There, it contributes to the greenhouse effect, which drives global warming.

Oil pumps and other types of petroleum-industry equipment may soon be regulated to reduce methane emissions. Credit: © PhotoStock10/Shutterstock

The greenhouse effect is caused by certain gases in the atmosphere that let sunlight pass into the atmosphere but trap heat close to the planet’s surface. Although the greenhouse effective existed long before people evolved, human activity, especially since the Industrial Revolution, has likely added to it. One such activity is the burning of fossil fuels, such as coal, oil, and natural gas. This burning releases large amounts of the greenhouse gas carbon dioxide. But human activities, including drilling for fuel, have also produced emissions of another greenhouse gas—methane.

Methane is a powerful greenhouse gas. A molecule of methane lasts for an average of 12 years in the atmosphere before being broken down by sunlight. This is much shorter than carbon dioxide, which can linger in the atmosphere for thousands of years. The molecular structure of methane, however, makes it much more efficient at trapping heat than carbon dioxide. In fact, methane is 25 times more powerful than is carbon dioxide when it comes to contributing to the greenhouse effect, even with its relatively short lifespan.

The Obama administration and its allies want to cut methane emissions as part of a broader strategy to reduce the amount of greenhouse gases the United States produces. Oil and gas companies and some members of the U. S. Congress oppose the plan, saying it will increase the cost of energy. Some environmental groups also criticized the proposal. They argue that it does not go far enough because it will not hold existing wells to the same high standards.

Other World Book articles:

• Carbon Offsets: Reducing Your Footprint (Special report)
• Methane: Another Greenhouse Troublemaker (Special report)

July 3, 2013

Weather extremes unprecedented in records kept since 1850 pummeled Earth during the decade of 2001-2010, the World Meteorological Organization (WMO) reported today. The decade was the warmest for both hemispheres and for both land and ocean surface temperatures. The year 2010 was the warmest ever recorded, with an average temperature estimated at 1 Fahrenheit degree (0.54 Celsius degree) above the long-term average during the 1961-1990 base period. More national temperature records were reported broken than in any previous decade.

Extreme heat waves, particularly in Europe in 2003 and in Russia in 2010, caused a record number of deaths. The record high temperatures were accompanied by the rapid melting of Arctic sea ice, Antarctic ice sheets, and Greenland glacier ice. As a result, global mean sea levels rose during the 2001-2010 decade by 1/8 inch (3 millimeters) per year–about double the average rise of 1/16 inch (1.6 millimeters) during the 20th century.

Scientists believe that higher ocean temperatures are generating hurricanes of greater severity. (AP/Wide World)

The authors of the report analyzed trends, both global and regional, and such extreme events as Hurricane Katrina, floods in Pakistan, and droughts in the Amazon, Australia and East Africa. They noted that the decade of 2001-2010 was also the second wettest since 1901 and that 2010 was the wettest year ever recorded. They attribute the unprecedented weather extremes mainly to greenhouse gases generated by human action.

Additional World Book articles:

• Global warming
• Australia 2008 (a Back in Time article)
• Australia 2009 (a Back in Time article)
• Australia 2010 (a Back in Time article)
• Europe 2003 (a Back in Time article)
• Russia 2010 (a Back in Time article)
• Twisted–More Terrible Storms (a special report)

March 15, 2013

For the first time, scientists have extracted natural gas from methane-hydrate deposits, Japanese researchers announced this week. Methane hydrate is methane gas trapped in frozen water–the substance forms an icelike solid. When burning, methane hydrate looks like ice on fire. Deposits of methane hydrates are found in the Arctic, the Antarctic,and along offshore areas of continents.

A map of the known and inferred methane-hydrate deposits created by the United States Geological Survey. (USGS)

Scientists have been searching for a practical and economical method of extracting methane hydrate. Earth’s deposits of this compound form a larger resource of hydrocarbons than oil, natural gas, and coal combined.  Japan imports a huge amount of fuel for energy, so the ability to extract the methane off of Japan’s coast for energy would be an economic boon to the nation. This is particularly true now that Japan has shut down most of its nuclear power plants after the meltdown and leak of radioactive materials at Fukushima in 2011. Japan has invested hundreds of millions of dollars into research on methane hydrates. In the current successful experiment, scientists used depressurization to release the methane from its hydrate bond.

Environmentalists are concerned about the process of extracting methane in this fashion. Methane is about 20 times as powerful as carbon dioxide as a greenhouse gas.  If a sizable amount of methane gas was freed into the atmosphere during the extraction process, it could have a large and unpredictable effect on Earth’s climate. Geologists are also studying whether mining for methane hydrates could destabilize the seabed, potentially causing tsunamis.

Additional World Book Articles:

• Environment
• Exploring the Ocean Abyss (A Special Report)
• Methane: Another Greenhouse Troublemaker (A Special Report)