What is Causing Heavy Rains and Droughts?

People walking in intense rain and person walking in drought stricken area

What is Causing Heavy Rains and Droughts?

Image Credits:

Atilla Bingol and Vicky Sim | Unsplash

The effects of climate change are being experienced globally. Severe storms, heavy winds, and rains are causing floods, while extreme droughts are fueling wildfires. In recent years, a larger percentage of precipitation has come in the form of intense single-day events.

Why are some locations becoming wetter, as others are becoming substantially drier? The short answer - Hotter greenhouse gases from human activity are causing earth's water to be redistributed globally.

Extreme climate changes can affect various aspects of society in negative ways. People, businesses, and cities are being effected as the death toll and financial costs rise from the catastrophic damage.

Heavy Rains and Droughts

The weather and climate are changing. The world is experiencing extremes in weather related events. Temperatures are rising. Some areas of the planet are experiencing severe storms, strong winds, heavy rains - and floods, while others are experiencing extreme heat, droughts and wildfires.

Why are some locations becoming wetter, as others are becoming substantially drier? Hotter greenhouse gases from human activity are causing earth's water to be redistributed globally.

Widespread changes in weather patterns are linked to rising global average temperatures. Extreme weather events such as heat waves and large storms are likely to become more frequent or more intense with human-induced climate change.

Already this year, people and cities have experienced severe storms, strong winds and heavy rains, floods, and fires have caused widespread damage and deaths worldwide.

The U.S., is experiencing an increasing a number of disaster type events related to extreme weather. As of October 18, 2021, there have been at least 104 Declared Disasters.

Since June 2021, China’s heavy rainfalls have impacted a number of cities. In mid-July 2021, a slow-moving rainstorm made rivers and reservoirs spill over their banks, leading to deadly flooding in central China. According to some reports, the rainstorm dropped a year’s worth of rain on Zhengzhou, the province’s capital city, over the span of three days.

Since July 2021, a number of European countries have been affected by heavy rains and floods. From the U.K. to Germany, heavy floods have caused widespread damage and resulted in a number of deaths.

Between July 12 and 15, 2021, at least 220 people in Germany and Belgium were killed by floods caused by heavy rains.

One scientific study, conducted by 39 scientists and researchers from 8 countries, estimated Germany’s floods were up to 9 times more likely due to human caused climate change.

For September, the average contiguous U.S. temperature was 67.8°F, 3.0°F above the 20th-century average, the fifth-warmest September in the 127-year period of record.

The September precipitation total for the contiguous U.S. was 2.33 inches, 0.16 inch below average, ranking in the middle one-third of the 127-year period of record. Precipitation was above average across portions of the Northwest, Southwest, northern and central Plains and from the central Gulf Coast to New England.

Weather and Climate

Weather is the state of the atmosphere at any given time and place. Most of the weather that affects people, agriculture, and ecosystems takes place in the lower layer of the earth’s atmosphere.

Earth's atmosphere The Earth’s atmosphere, often known as air, is the layer of gases retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The Karman line, which is about 62 miles in altitude, is a commonly accepted boundary between the Earth’s atmosphere and space.

Weather includes temperature, precipitation, clouds, and wind. Severe weather conditions include hurricanes, tornadoes, blizzards, and droughts.

Climate is the average weather in a given area. Weather can change over brief periods throughout the day or weeks, while changes in climate develop over longer periods of years.

Average temperature and precipitation are often used to define climate. However, climate can also be defined by the type, duration, frequency, and intensity of weather events such as heat waves, storms, heavy rains, cold spells, floods, and droughts.

Rising temperatures and shifting precipitation patterns

Droughts can be triggered by rising temperatures and shifting precipitation patterns.

Extreme high and low temperatures are becoming more frequent.

In the U.S., heat waves are occurring more frequently. Today, heat waves occur three times more often than in the 1960s.

Since 1998, eight of the top 10 warmest years on record have occurred.

The last 50 years have been wetter on average, yet specific U.S. regions have experienced more droughts. Droughts vary, as widespread droughts were seen in the 1930s and 1950s.

What causes heavy rains?

Heavy, more intense rains, are the result of Climate Change. The frequency and intensity of precipitation is being affected. Precipitation is water like rain, snow, sleet or hail.

The amount of water that evaporates into the air increases with warmer oceans. Heavier rain and snow storms result from more intense precipitation caused by more moisture-laden air as it moves across land or converges into a storm system.

Rain and snow do not fall in a uniform pattern across the globe. Some areas are consistently damp, while others are consistently dry. Amounts in a location can vary annually and from season to season.

Heavy precipitation events can be measured by tracking their frequency.

In the U.S., the average precipitation can vary widely. While the Southwest has an average perception of less than 3 inches a year, Atlanta has about 50 inches. Seattle has about 39.34 inches of precipitation over about 155 days a year.

Precipitation is occurring in more intense events. The total amount of precipitation at a location isn’t necessarily increasing.

What causes a drought?

Droughts are caused by drier-than-normal circumstances, which can lead to water shortages. Tree rings
Super hot temperatures can worsen drought effects by evaporating moisture from the soil.

Less than average, abnormal amounts of precipitation in a region are known as droughts. When a region is hot and dry as usual, it is not actually considered a drought.

Precipitation doesn’t fall evenly across the planet.

According to NASA research, droughts have been influenced by humans for nearly a century.

Tree rings are the smoking gun. Drying and wetting patterns provide a data “fingerprint” for scientific analysis. These fingerprints have predicted areas of Asia would become wetter due to greenhouse gases.

As Earth’s atmosphere is warming due to greenhouse gases. These gases that trap heat reside in the earth’s atmosphere.

What are Greenhouse Gases?

Greenhouse gases are heat trapped in the earth’s atmosphere. These gases are increased with human activity such as burning of:

Carbon dioxide - Results from fossil fuels (coal, natural gas, and oil) and other biological materials.

Methane - Comes from the production and transportation of coal, natural gas, and oil. Also occurs from livestock and other agricultural practices, land use and by the decay of organic waste in municipal solid waste landfills.

Nitrous oxide - Emitted during agricultural, land use, industrial activities, combustion of fossil fuels and solid waste, and wastewater treatment.

Fluorinated gases - Greenhouse gases produced from a variety of industrial processes.

Three greenhouse gases determining factors:

How much is in the atmosphere?
How long do they stay in the atmosphere? and
How strongly do they impact the atmosphere?

Human activity is resulting in hotter greenhouse gases. Climate Change is redistributing the earth's water and producing extreme weather events in the form of heavy rains and droughts.