May 29, 2013

A wildfire in Los Padres National Forest in California’s Santa Barbara County had by the afternoon of May 28 burned across some 1,800 acres (730 hectares) in less than 24 hours. More than 550 firefighters–from the county, area cities, and U.S. Forest Service–continued to battle the so-called White Fire, which was 65 percent contained as of late last night, reported officials at the Santa Barbara County Office of Emergency Management.

A smoke jumper parachutes into a burning wildland area (place with land in its natural state) to fight a fire. Such firefighters are able to reach fires in remote areas that would be difficult to access by other means. (© Mike McMillan, Spotfire Images)

Southern California is in the middle of a drought, and the vegetation that is fueling the fire is extremely dry. In addition, the fire is being driven by winds of between 20 and 30 miles (32 and 48 kilometers) per hour. The National Weather Service was predicting continuing gusts of from 45 to 65 miles (72 and 105 kilometers) per hour. Officials estimate that from 2,000 to 3,000 people have evacuated the area since the fire broke out on the afternoon of May 27.

Additional World Book articles:

• When the Rain Stops (a special report)
• Why Forests Need to Burn (a special report)

November 14, 2012

A catastrophic drought lasting nearly 100 years caused the downfall of the Maya in Central America more than 1,000 years ago, according to a new report by climate researchers led by Douglas Kennett of Pennsylvania State University. Archaeologists have long thought that climate change in the form of long drought was a factor in the collapse of the Maya, but detailed climate information was difficult to find in the archaeological record.

Ruins of an ancient Maya temple stand at Palenque in the state of Chiapas. The temple was built about A.D. 650, during a period when great indigenous (native) civilizations thrived in Mexico. (© Ales Liska, Shutterstock)

The Maya developed a magnificent civilization in Central America and south Mexico that reached its peak from about A.D. 250 to 900. During that time, known as the Classic Period, the Maya civilization was centered in the tropical rain forest of the lowlands of what is now northern Guatemala. Then, beginning in the 800′s, the Maya abandoned their major cities in the lowlands one by one and finally abandoned most of this region. Archaeologists have no clear explanation for why the Classical Maya civilization, known for its remarkable architecture, painting, sculpture, advancements in astronomy, and an accurate yearly calendar, collapsed so dramatically.

Kennett and his team were able to obtain detailed evidence about rainfall by measuring oxygen isotope levels in a stalagmite, a stone formation that rises up from the floors of caves, from a site in southern Belize. (Different isotopes [forms] of a chemical element, such as oxygen, contain different amounts of matter in the nucleus [core] of their atoms.) Stalagmites form when water, dripping on the floor from the walls and roofs of the cave, carries with it deposits of calcium carbonate, or calcite. Rainfall in a region can be calculated and linked to specific dates by measuring the ratio of radioactive oxygen isotopes in the layers of a stalagmite. The analysis by Kennett’s team indicated a long-lasting, severe drought from 660 to 1000 A.D., which corresponds to the collapse of Classical Maya civilization. The period of drought apparently intensified other factors, including overpopulation, disease, exhaustion of natural resources, and warfare, to bring an end to the Classical Maya civilization.

A Mayan mural depicts a scene at the royal court at Bonampak, where the king (center) is presented with prisoners captured in battle. Defeated rulers and other important prisoners of war were sacrificed to the gods in religious ceremonies. This restored mural was painted toward the end of the Classic Period, around 790 A.D., as rival cities in the Mayan civilization began to fight each other. (© Della Zuana Pascal, Sygma/Corbis)

However, the culture of the Maya never really disappeared. Today, descendants of the Maya still live in Mexico and Central America. They speak Maya languages and carry on many customs of their ancestors.

Additional World Book articles:

• Architecture (Pre-Columbian architecture)
• Stephens, John Lloyd
• The Ancient Maya: Deciphering New Clues (a Special Report)

August 9, 2012

Global food prices are rising due to wild swings in weather conditions, the United Nations Food and Agriculture Organization (FAO) announced today. The drought in the United States, combined with untimely rains in Brazil and production problems in Russia, sent food prices up by 6 percent in July 2012. The severe deterioration of the U.S. corn crop due to extensive drought damage pushed corn prices up by more than 30 percent in July. Cereal prices climbed by 17 percent and sugar by 12 percent. (Corn is an especially important source of sugar-rich syrups in the United States. The consumption of corn sweeteners in the United States is about equal to the consumption of sucrose.)

Drought conditions in the United States have caused severe damage to corn crops, pushing up food prices worldwide. (AP/Wide World photo)

Rising food prices have already caused a food crisis in the Sahel sub-region of west and central Africa, affecting more than 18 million people. The situation has renewed fears of the kind of food crisis that resulted in violent street protests in Egypt and Haiti in 2007 and 2008. “This is not some gentle wake-up call–it’s the same global alarm that’s been screaming at us since 2008,” notes Hannah Stoddart, Oxfam’s head of economic justice policy. (Oxfam is an international confederation of 17 organizations that work directly with communities to ensure that poor people can improve their lives and livelihoods.)

July 2012 was the hottest single month on record for the continental United States since record keeping began in 1895, the National Oceanic and Atmospheric Administration reported yesterday. The average temperature across the lower 48 states was 77.6 °F (25.3 °C), 3.3 Fahrenheit degrees above the 20th-century average. The first seven months of the year were the warmest of any year on record and were drier than average. The excessive heat and drought have led Agriculture Secretary Tom Vilsack to declare more than half of all counties in the United States disaster zones.

Additional World Book articles:

• Federal Emergency Management Agency (FEMA)
• When the Rain Stops (a special report)

July 20, 2012

In the face of the worst drought in the United States in more than 50 years, soybean futures prices hit record highs yesterday. Soybean futures for November delivery climbed 1.8 percent, to an all-time high of $16.49 a bushel, at the Chicago Board of Trade. The weekly U.S. Drought Monitor showed more than 70 percent of the Midwest in some stage of drought, with more than half of the region in “severe” to “exceptional” drought. The U.S. Department of Agriculture has so far during the 2012 crop year designated 1,297 counties across 29 states drought-related disaster areas, making qualified farm operators in the areas eligible for low-interest emergency loans. The last drought in the United States of this magnitude was in 1956.

A farmer examines a field of corn stunted by a drought. (AP/Wide World)

Additional World Book articles:

• Federal Emergency Management Agency (FEMA)
• When the Rain Stops (a special report)
• Weather 1956 (a Back in Time article)

July 11, 2012

The average temperature across the continental United States for the first six months of 2012 was the warmest on record, announced the National Oceanic and Atmospheric Administration on July 9. The 12-month period ending on June 30 was also the warmest on record in the 48 contiguous states. Record keeping was begun by the National Weather Service in 1895. The average temperature through June–57.4 °F (14.1 °C)–is 4.5 degrees higher than the long-term average for the same period. In Colorado, the average temperature in June was 6.4 degrees higher than the historical average.

High temperatures in the second half of June broke or tied records in 173 locations across the nation. The temperature hit 115 °F (46.1 °C) on June 26 in Red Willow, Nebraska, breaking the 114 °F (45.5 °C) record set in 1932. The temperature reached an all-time high of 118 °F (47.7 °C) on June 28 in Norton, Kansas.

High temperatures in June contributed to a record-warm first half of the year and the warmest 12-month period the United States has experienced since record keeping began in 1895. (National Oceanic and Atmospheric Administration)

The first six months of the year were also drier than usual, with total precipitation 1.62 inches (4.11 centimeters) below average. According to the Weather Service’s weekly Drought Monitor, 56 percent of the nation experienced drought conditions in June.

The unusually high temperatures and drought conditions created ideal conditions for wildfires. Wildfires burned across 1.3 million acres (526,000 hectares) in the western United States in June alone.

Additional World Book article:

• Weather
• The Forecast: Better Weather Prediction Ahead  (a special report)
• When the Rain Stops (a special report)
• Weather 1932 (a Back in Time article)

July 6, 2012

Drought conditions are present in 56 percent of the continental United States, the National Weather Service announced on July 5. The prolonged heat wave across the Midwest is not only setting record high temperatures, it is expanding and intensifying drought conditions. “This year the high temperatures have certainly played into this drought,” noted Brad Rippey, a meteorologist with the U.S. Department of Agriculture. “There’s a lot more evaporation . . . and crop demands for water.”

Corn stunted by lack of rain (courtesy of AP/Wide World)

According to the Weather Service’s weekly Drought Monitor, the drought is starting to “take a significant toll” on food supplies. . . . “In the primary growing states for corn and soybeans, 22 percent of the crop is in poor or very poor condition, as are 43 percent of the nation’s pastures and rangelands and 24 percent of the sorghum crop.” The extreme heat has taken an especially high toll on corn crops, driving up prices. The ongoing drought is also forcing ranchers in the West to ship cattle to market, driving down beef prices.

Additional World Book article:

• When the Rain Stops (a special report)

March 19, 2012

A drought that began in Mexico in 2010 has turned into the worst that the country has experienced since official weather record keeping began in 1941, according to Mexican officials. At least two-thirds of Mexico’s 31 states are experiencing extremely dry conditions with below-normal rainfall. The north-central states of Coahuila, Durango, San Luis Potosi, and Zacatecas have been hardest hit. However, government officials are also concerned about drought in Guanajuato, one of the top food-producing states in the country. Mexican farmers produce large quantities of beans, corn, onions, and tomatoes, both for export and as food for their own people. Mexico is also the chief supplier of cattle to the United States. According to some estimates, food production across Mexico has fallen by 40 percent, raising food prices.

(World Book map; map data © MapQuest.com, Inc.)

Farmers who rely on rainfall to water their crops and livestock were the first to experience hardship. Rain has fallen in some states at only half the usual levels. As the dry conditions have continued, lakes and reservoirs have fallen to critically low levels. Many farmers are no longer able to irrigate their crops, and ranchers cannot supply their cattle with water. Several towns have run out of drinking water. The government has begun delivering emergency food and water supplies to thousands of people, and about 2 million others lack adequate food.

Some meteorologists expect the drought to continue for at least several more months. They believe the dry spell is the result of a La Nina. A La Nina is a weather phenomenon in which the waters of the eastern Pacific Ocean become colder and the climate becomes drier. A La Nina follows the better-known weather condition known as an El Nino. During an El Nino, waters of the eastern Pacific Ocean become warmer and the climate becomes wetter. One of the strongest La Nina’s in more than 10 years occurred from 2010 to 2011. Texas has also been experiencing a severe drought.

Additional World Book article:

• Food supply

Feb. 3, 2012

China’s largest freshwater lake, Poyang, has gone dry, the state news service, Xinhua, announced this week. The normally 1,350-square-mile (3,500-square-kilometer) lake is now a dried-out plain that stretches as far as the eye can see. According to the news agency, the situation is the result of drought–the worst in 60 years–in the area around Poyang and the rivers that feed into the lake. While poor weather conditions are partly responsible, conservationists point out the role played by the Three Gorges Dam. The colossal dam and reservoir are 310 miles (500 kilometers) upstream from the lake.

“Every year, when the Three Gorges reservoir stores water–to power the dam’s [electric power-generating] turbines during the winter–the flow rate in the Yangtze [River] drops. This in turn increases the rate at which the level of Poyang lake falls, and the period of low water comes sooner,” states Ye Xuchun, a researcher at China’s Southwest University. Although the Chinese government has yet to acknowledge this cause and effect, the government did admit in May 2011 that the Three Gorges, which is the largest dam on the planet, has produced “problems that need to be solved very urgently.”

Three Gorges Dam, on the Yangtze River in Hubei Province, is the world's largest dam. It is designed to control flooding and generate hydroelectric power. © Reuters/Landov

Dai Nianhua, deputy head of the Lake Poyang Research Center in Nanchang, the provincial capital, has pointed out that the dried up lake seriously affects the region’s balance of nature. When the level in the lake is too low, the fish die. This leaves no food for migrating birds that normally feed at Poyang.

The economic consequences are also serious. Fishers are unable to make a living, and all shipping across the normally busy lake has come to a standstill.

Additional World Book articles

• Back in Time 1996 (Environmental pollution)
• Back in Time 2003 (China)
• Back in Time 2003 (Environmental pollution)

Two people have died in the massive Bastrop wildfire burning out of control about 30 miles (48 kilometers) southeast of Austin, the Texas capital. More than 700 homes have been destroyed in what is currently the largest of dozens of wildfires burning throughout the drought-stricken state. On September 4, a fire in east Texas killed a 20-year-old woman and her 18-month-old daughter trapped in their burning home.

At least 57 separate wildfires in Texas have burned across more than 100,000 acres (40,470 hectares) over the past week, Texas Governor Rick Perry announced at a September 6 news conference. According to the Texas Forest Service, one of the fires, the Bastrop fire, has burned across an estimated 30,000 acres (12, 140 hectares) in Bastrop County, forcing thousands of people to evacuate. A separate, smaller wildfire south of Austin has moved unchecked for at least 16 miles (25 kilometers) and has twice jumped the Colorado River.

Additional World Book article:

• When the Rain Stops (special report)