Relationship between Flooding and Climate Change

 Relationship between Flooding and Climate Change:

For billions of years, the climate has been fluctuating in small amounts for long durations of time. With the change in temperature came a change in the carbon dioxide ppm in our atmosphere. As of March 17, 2022, we are at 418.14 ppm, which is way higher than any number before. (NOAA).

However, the destruction of species has resulted from almost every time a major climate change event occurred. In the ice age, for example, millions of animal species like the mastodon perished. Observing current trends with carbon dioxide, we can expect this wave to impact earth more than ever before.

Another major impact of climate change that has been observed today is on the way water moves around our world. Record-breaking floods are one prime example of how our lives have been transformed by the climate crisis. But there’s no doubt that the levee is breaking when it comes to climate action, too. 

Here are some stats and figures about floods:

• While hurricanes and earthquakes can grab attention and headlines, floods and droughts are actually some of the most dangerous natural disasters.

• In addition to the death tolls of floods, they can also cause more than $40 billion in damage on average around the globe every year (National Geographic) .

• As a result of climate change, “land currently home to 300 million people will fall below the elevation of an average annual coastal flood” by 2050 (Climate Central ).

FACTBOX: How does climate change relate to floods? As humans burn fossil fuels, and we add greenhouse gases to our atmosphere, we are warming our planet. This results in more water evaporating into our atmosphere. Plus, as the air gets warmer, it can actually hold more water vapor. More water in our atmosphere means more intense precipitation and more intense storms. 

A WETTER WORLD:

In other words, climate change impacts our weather largely by putting our water cycle into overdrive. As temperatures around the globe climb, water from land and sea is evaporating faster – leading to more intense precipitation events and intensifying storms.

There has been a clear correlation found between time and the relative number of extreme events. With the increase in Climate Change and CO2 ppm, there has also been an increase in heavy precipitation in the United States.

TYPES OF FLOODS

When we talk about the links between climate change and flooding, it’s useful to remember that there are at least four different types of flooding events. (And all of them are affected by climate change.) Here’s how the National Climate Assessment defines these different phenomena (NCA):

• Flash floods “occur in small and steep watersheds and waterways and can be caused by short-duration intense precipitation, dam or levee failure, or collapse of debris and ice jams. Most flood-related deaths in the US are associated with flash floods.”
   

• Urban flooding “can be caused by short-duration very heavy precipitation. Urbanization creates large areas of impervious surfaces (such as roads, pavement, parking lots, and buildings) that increased immediate runoff, and heavy downpours can exceed the capacity of storm drains and cause urban flooding. Flash floods and urban flooding are directly linked to heavy precipitation and are expected to increase as a result of increases in heavy precipitation events.”

• River flooding “occurs when surface water drained from a watershed into a stream or a river exceeds channel capacity, overflows the banks, and inundates adjacent low-lying areas. Riverine flooding depends on precipitation as well as many other factors, such as existing soil moisture conditions and snowmelt.”
   

• Coastal flooding “is predominantly caused by storm surges that accompany hurricanes and other storms that push large seawater domes toward the shore. Storm surge can cause deaths, widespread infrastructure damage, and severe beach erosion. Storm-related rainfall can also cause inland flooding and is responsible for more than half of the deaths associated with tropical storms. Climate change affects coastal flooding through sea level rise and storm surge, and increases in heavy rainfall during storms.”

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THE AMERICAN MIDWEST/ IOWA

Across the US, heavy downpours are increasing – especially in the Northeast, Midwest, and upper Great Plains regions. Since 1991, these areas have seen 30 percent more precipitation on the heaviest rain days, which the National Climate Assessment describes as “significantly above average(NCA ).

Another major example to take in is Davenport, Iowa, which captured national headlines in 2019 after it experienced very heavy flooding. The reason for the floods was in part because the region had both record-breaking precipitation and “more than a year's worth of runoff in the span of three months” (DesMoinesRegister). 

Climate scientist Kevin Trenberth told Inside Climate News in 2017 that  "of course there is a climate change connection, because the oceans and sea surface temperatures are higher now because of climate change, and in general that adds 5 to 10 percent to the precipitation. There have been many so-called 500-year floods along the Mississippi about every five to 10 years since 1993" (Inside Climate News ).     

Businesses in Davenport and other cities similar to it each lost thousands of dollars while the community fought to recover. One brewery owner, Tim Baldwin, complained that “the real big kicker for us at the restaurant has been lost revenue during our busiest season — about $200,000 in profit over seven months that basically represents a year's worth of profit. Insurance doesn't cover that” (QC Times ).

Additionally to businesses, the floods stripped people of their homes, food, pets, agriculture, and lives. This goes far beyond just one flood. Climate change is making the food supply we all depend on less secure. If we don’t act, climate-change worsened flooding will continue to have an enormous impact on our infrastructure and our health.