Since 1901, global precipitation levels have increased by an average rate of 0.04 inches per decade, whereas in the contiguous United States, annual precipitation levels have been increasing at a rate of 0.20 inches per decade, according to the EPA.
Climate change has become one of the most pressing issues of our time, with far-reaching consequences for our planet. One of the most significant effects of climate change on our planet is its impact on precipitation patterns. As temperatures continue to rise, the Earth’s climate system becomes disrupted, leading to changes in rainfall distribution and intensity.
Locally, extreme rain events in Leominster, Massachusetts have led to emergency evacuations and a state of emergency. On Monday, September 11, slow-moving thunderstorms caused flash flooding across parts of New England, dumping 9.5 inches over Leominster. The rain washed out roadways, formed sinkholes and sent floodwaters into buildings. Now, officials are concerned about two dams, several damaged structures and Massachusetts Bay Transportation Authority (MBTA) commuter rail tracks that were left dangling in mid-air.
According to WCVB, a news station in Boston, city infrastructure repairs will cost the town anywhere from $25 to $40 million, not including the cost of fixing businesses and homeowners. This is just one of many examples of catastrophes caused by extreme rainfall.
One of the main ways that climate change affects precipitation patterns is through altering the water cycle. According to the EPA, as temperatures on Earth’s surface continue to rise, more evaporation occurs, causing more water vapor to enter the atmosphere.
In fact, for each degree Celsius that the planet warms, the air’s capacity for water vapor increases by 7%. All of this excess moisture leads to heavier and more intense rainfall events when it eventually condenses and falls as precipitation. Regions that experience increased evaporation are likely to see an increase in heavy downpours. In fact, current climate models by NASA show that this increase in evaporation will result in more frequent and intense storms when atmospheric conditions are favorable, so storm-affected areas are more likely to experience increases in precipitation and risk of flooding.
Additionally, climate change has an influence on atmospheric circulation patterns, such as the jet stream. The jet stream has a crucial role in determining weather patterns by changing the direction of storms and influencing where they make landfall. As global temperatures rise, these circulation patterns can become disrupted or be shifted from their typical paths. This can result in altered storm paths, impacting precipitation distribution across different regions.
Furthermore, El Niño and La Niña are two climate phenomena that have a significant impact on global weather patterns. They are a result of changes in ocean temperatures in the Pacific Ocean, as these have an impact on atmospheric circulation patterns. During El Niño events, the warm ocean waters in the Eastern Pacific cause changes in atmospheric pressure, leading to altered wind patterns. This results in a shift of the jet stream and storm tracks, causing more frequent and intense rainfall over certain regions. On the other hand, La Niña events occur when cooler sea surface temperatures occur in the Equatorial Pacific. During these periods, there is strengthening of winds, leading to enhanced evaporation from the ocean surface and increased moisture transport to local landmasses. These periods typically occur in regions of Southeast Asia and Australia.
Lastly, human usage of fossil fuels is causing rapid changes to global climate. When fossil fuels are burned for electricity, heat, and transportation, carbon dioxide is being emitted into the air. This greenhouse gas traps solar radiation, causing the Earth’s global temperature to rise. This sudden increase in temperature is fueling climate disasters.
The consequences of these changing precipitation patterns can have huge impacts on our planet. Increases in heavy rainfall events can lead to more frequent flooding and landslides, posing risks to both humans and infrastructure. Risk of flooding is increased in urban areas, where non-permeable pavement forces water to quickly run off into sewer systems.
Other consequences include lower water quality, which can severely harm human health, aquatic ecosystems, and fishing operations. Storm water runoff, including pollutants such as heavy metals, pesticides, nitrogen, and phosphorus, can end up in lakes, streams, and bays. This is a major issue in cities that use a combined sewer system, where heavy rainfall can overwhelm systems and send excess storm water, wastewater, and untreated sewage right into bodies of water. In terms of agriculture, more precipitation can lead to soil erosion, reductions in number of crops, and disruption of ecosystems.
Heavy rainfall can also increase risk of landslides. When precipitation levels are above average, they raise the water table and saturate the ground, causing slopes to lose their stability and causing increased risk of landslides,
Extreme weather events have been encountered in various parts of the United States. In July, 2023, Connecticut, Vermont, and New York’s Hudson Valley had “1000-year rains” (Yahoo News), resulting in extreme flash floods that killed five people in Pennsylvania. New Hampshire’s Mount Washington received 16.91 inches of rain, and Boston got three times its average rainfall, making it the second wettest July the city has on record. Between 1951 and 2017, temperatures in the Great Lakes Region have increased by 2.3 degrees Fahrenheit, its annual rainfall went up by 17%, and its heavy rain events increased by 35%, according to Yahoo.
In order to lower precipitation levels, we must find solutions to the underlying problem: climate change. Small changes to lifestyles can have a huge impact on climate change. Driving less, either by walking, carpooling or taking public transport, can help save one pound of carbon dioxide per miles that wasn’t driven. Recycling can help save 2400 pounds of carbon dioxide per year, just by recycling half of your household waste. Adjusting your thermostat can also have a huge impact.
Turning the thermostat down 2 degrees in the winter and up 2 degrees in the summer can help save 2000 pounds of carbon dioxide. These, along with many other solutions, are the key to reducing the impact of climate change on our planet.
