As a result of April 2022 flooding, a river burst its banks and destroyed a bridge in Durban, South Africa.
Credit: © Rogan War, Reuters/Alamy Images

Several days of heavy rain have caused severe flooding and mudslides on the east coast of South Africa. A new storm came off the Indian Ocean on Tuesday, April 12th, destroying bridges, roads, houses, and other structures. The storm hit the city of Durban, South Africa’s chief seaport and one of its largest cities, killing at least 443 people. Officials report that 63 people remain missing amidst the damage in the province of KwaZulu-Natal.

The influx of rain is a result of a weather phenomenon called a cut-off low, which occurs when a low-pressure system is disrupted and moves slowly across an area. The storm produced the heaviest rains in South Africa in 60 years and is the deadliest storm on record in the country. Meteorologists estimate that over a month’s worth of rain, nearly 12 inches (30.5 centimeters), fell in one day in Durban.

The downpour of rain caused mudslides that washed away entire hillsides, destroying nearly 600 schools and  60 health facilities. More than 12,000 homes have been damaged from the flooding and mudslides. Some schools were in session during the storm, trapping students and teachers inside. Many people sought higher ground and climbed on top of roofs to stay out of reach of the rushing water and mud.

The flooding also washed out complete roads and bridges. One bridge outside Durban collapsed, leaving people stranded on both sides. The rushing water knocked out all power in the area. The mudslides and damage cut off the supply of clean water. Stacks of shipping containers have collapsed into the water.

Rescue efforts continue to find missing people believed to be underneath houses affected by the mudslides. South African President Cyril Ramaphosa visited with people affected by the disaster and pledged to help rebuild the community.

December 28, 2015

During the Christmas weekend, weather patterns around the world produced a variety of extremes, from torrential rains and flooding in North America, South America, Europe, and Australia to fierce snowstorms in North America and raging wildfires in Australia.

Fire-damaged buildings are seen alongside a house that survived the Christmas Day bushfires at Separation Creek in the Otway Ranges south of Melbourne, Australia, on Dec. 27, 2015. Credit: © Julian Smith, EPA/Landov

Heavy storms pounded the Midwestern and Southern United States with rain and snow. Tornadoes with winds of up to 200 miles (320 kilometers) per hour tore through Texas, killing at least 11 people. Meanwhile, some areas of New Mexico received more than 1 foot (0.3 meter) of snow. At least 43 people died throughout the United States as a result of these storms and the flooding that followed. Meteorologists noted that higher-than-average temperatures contributed to the severity of the storms.

In Australia, a lightning strike in the southeastern state of Victoria on December 19 caused a series of wildfires known as bushfires. The fires grew in size and intensity and destroyed more than 100 homes on Christmas Day. Meanwhile, monsoon rains caused major flooding in the Northern Territory, forcing hundreds of people to evacuate their homes. At the same time, in South America, more than 100,000 people fled their homes in areas of Argentina, Brazil, Paraguay, and Uruguay to escape flooding caused by heavy rainfall. In northern England in the United Kingdom, downpours led to extensive flooding as dozens of rivers overflowed.

Authorities noted that El Niño conditions were to blame for much of the extreme weather. An El Niño is a part of the interaction between Earth’s atmosphere and the tropical waters of the Pacific Ocean. El Niños occur about every two to seven years, and can affect climate throughout the world. The term El Niño originally referred to a current of warm water that flows southward along the coast of Ecuador and Peru, in western South America, every winter. About every two to seven years, the warm current is abnormally strong, lasts for an unusually long time, and is accompanied by changes in the winds and precipitation across the entire tropical Pacific region. For this reason, El Niño came to refer to the entire interaction of the ocean and atmosphere during the period of the stronger-than-normal current. According to the World Meteorological Organization, a United Nations affiliate, this year’s El Niño is the strongest in more than 15 years.

Other World Book articles: 

• Christmas Eve Storms Hit United States (Dec. 25, 2015) – A Behind the Headlines article
• Meteorology
• Weather

December 10, 2015

December saw flooding in several parts of the world, with separate weather events inundating portions of the United Kingdom and Ireland, southeast India, and the United States Pacific Northwest.

A woman collects drinking water at a residential area flooded with rainwater in Chennai, India, on Dec. 6, 2015. Credit: © Arun Sankar K, AP Photo

Early in the month, Storm Desmond set a record for 24-hour rainfall in the United Kingdom, dropping 13.4 inches (341 millimeters) in the northwestern county of Cumbria on December 5. Desmond was a type of large, swirling windstorm called an extratropical cyclone. The storm pushed an atmospheric river—a channel of intense moisture in the air—over the region, causing heavy flooding in parts of northern England, northern Wales, and southern Scotland, as well as central Ireland. The floods damaged thousands of homes and killed two people.

The city of Chennai, in southeast India, received 15.6 inches (397 millimeters) of rain over a two-day period in early December. The drenching followed a record-setting November that produced 47.1 inches (1196 millimeters) of total rainfall. The rains caused flooding throughout the state of Tamil Nadu, causing the deaths of more than 200 people and forcing thousands of others from their homes.

In the United States, both Portland, Oregon, and Seattle, Washington, received a month’s worth of rain over just a few days in early December. Heavy rains led to mudslides, sinkholes, and flooding in the Pacific Northwest, leaving thousands of homes without electric power and killing two people.

Additional World Book articles:

• Heavy Rains Trigger Massive Flooding in Australia – A Behind the Headlines article
• Storm Triggers Massive Flooding Along Australia’s East Coast – A Behind the Headlines article
• Worst Flood Ever in Alberta, Canada – A Behind the Headlines article
• Unprecedented Weather Extremes Reported – A Behind the Headlines article
• Study Links Global Warming to Some Extreme Weather Events – A Behind the Headlines article
• “Biblical” Rains Across Colorado’s Front Range – A Behind the Headlines article
• Florida Sinkhole Swallows Resort Villa – A Behind the Headlines article
• Florida Sinkhole Eats Boat and Swimming Pool – A Behind the Headlines article
• Death Toll Rises from Massive Landslide in Washington State – A Behind the Headlines article
• Storms Kill 31 in Southern states of U.S. and Mexico – A Behind the Headlines article
• Historic Flooding in South Carolina – A Behind the Headlines article

October 6, 2015

On October 5, people stand on the safety of a bridge as homes sit in floodwater in Charleston, South Carolina. Credit: © Mic Smith, AP Photo

Since Thursday, October 1, a low pressure system combined with storms related to Hurricane Joaquin have drenched South Carolina in record heavy rains. Between Friday and Sunday, 20 inches (50 centimeters) of rain fell in Columbia, the state capital and hardest-hit city. Fourteen people have died in the flooding, mostly by drowning, many by being trapped in cars in flash floods. Hundreds of people have had to be rescued from their homes. Authorities, however, are advising people not immediately threatened by rising waters to stay home and avoid flooded roads.

South Carolina Governor Nikki Haley called the record rainfall a 1,000-year storm. (Meteorologists use this term to mean a weather event that has a 1-in-1,000 statistical chance of happening in any given year.) Governor Haley and U.S. President Barack Obama (respectively) declared the region to be a state and federal disaster area.

The rains stopped this morning, but the risk of flooding is not yet reduced, as the waters continue to rise. Since Saturday, nearly 20 dams in the flooded region have been breached (water has flowed over the top of the dam) or have failed. These failures sent huge amounts of floodwater crashing down on areas surrounding lakes and rivers. Also, because the flooding has occurred in the central part of the state, the water must move to the coast to truly relieve the flooding in the midlands.

Other World Book articles

• Flash flood
• Flood

September 9, 2013

Human activities influenced at least some of the extreme weather events that occurred across the world in 2012, according to new research on the causes of 12 events that occurred on 5 continents and in the Arctic. The research, Explaining Extreme Events of 2012 from a Climate Perspective, included 19 studies conducted by 78 scientists working in 11 countries. All of the events would have occurred even without rising global temperatures, with “natural weather and climate fluctuations” playing “a key role in the intensity and evolution” of the events, the scientists concluded. However, they also reported compelling evidence that human activity—particularly the release of large amounts of carbon dioxide and other heat-trapping greenhouse gases from the burning of fossil fuels—contributed to about half of the events.

Earth’s average surface temperature rose by about 1.4 Fahrenheit degrees (0.76 Celsius degree) from the mid-1800′s to the early 2000′s. Researchers have also found that most of the temperature increase occurred from the mid-1900′s to the 2000′s. Natural processes have caused Earth’s climate to change in the distant past. But scientists have found strong, clear evidence that human activities have caused most of the warming since the mid-1900′s.

A new reports suggests that coastal flooding from ocean storms will increase because of global warming. (AP/Wide World)

The difficulty in determining whether and to what degree human activities are influencing storms, heat waves, and other extreme weather events has made scientists cautious about linking global warming to any particular event. Recent advances in computer modeling and a greater understanding of climate data, however, have greatly improved scientists’ ability to distinguish natural weather factors from human-related factors. The new report has added to scientists’ understanding of the impact that climate change “adds, or doesn’t add, to any extreme event,” said Thomas R. Karl, director of the National Climatic Data Center in Asheville, North Carolina.

The scientists concluded that natural weather patterns were responsible for heavy rains that caused devastating floods in India, China, and Japan and for high summer rainfall in the United Kingdom in summer 2012. In addition, climate change only slightly influenced extreme rains in New Zealand in December 2011 and in Australia from October 2011 to March 2012.

In the United States, climate change had little effect on the drought that struck the midwestern United States in the summer, the scientists reported. However, human activities played a role in the accompanying heat waves that struck that region as well as the eastern United States. Temperatures during these hot spells are higher now than in the past and occur four times as often. The authors of the study also suggested that global warming will increasingly lead to more coastal flooding like that which occurred during Hurricane Sandy.

Some of the strongest evidence involved the record loss of sea ice in the Arctic. The scientists concluded that this loss resulted “primarily from the melting of younger, thin ice from a warmed atmosphere and ocean. This cannot be explained by natural variability alone.”

Additional World Book articles:

• The Great Meltdown (a special report)
• Methane (a special report)
• Meltdown: Climate Change in the Arctic (a special report)
• Probing the History of Climate Change (a special report)
• Twisted–More Terrible Storms (a special report)
• What We Know About Global Warming (a special report)