The latest series of extreme weather events took place against the backdrop of rising global temperatures.
Therefore, it can be tempting to see the flood in different regions as a direct consequence of climate change and studies have shown that global warming is most likely affecting flooding.
Relationship between climate change and floods
Although it isn’t clear if climate change is inducing floods directly, scientists maintain that it’s certainly exacerbating many of the factors that do.
With higher temperatures, there is more evaporation from land, oceans and water bodies, which means a warmer atmosphere can hold more moisture experts suggest for every 1-degree Celsius rise in average temperature, the atmosphere can hold about 7% more moisture.
This makes storms more dangerous as it leads to an increase in precipitation intensity, duration and/or frequency, which ultimately can cause severe flooding.
A recent study, published by the journal Nature, showed that since 2002, precipitation extremes have been closely correlated with rising temperature as a result planet has become both drier and wetter at the same time.
“Droughts can be made worse by warmer air, which can draw moisture out of the ground. On the other hand, warm air can hold more moisture than cooler air, which means that it can bring additional water into an area that is already saturated with water.
Also, higher global temperatures have resulted in the melting of glaciers and ice sheets, leading to an increase in sea levels, which puts coastal regions at higher risk of flooding.
According to a 2022 report by NOAA Climate, the global mean sea level has risen about 21-24 centimetres since 1880
Is climate change a reason for flooding?
However there are limited historical records, particularly for the most catastrophic floods, which occur less frequently.
Moreover, as mentioned before, there are too many factors (like local weather patterns, soil character, and topography of the affected area) at play to pick and blame for flooding in a region.
Similarly, scientists are yet to figure out the relationship between tornadoes and climate change.
This isn’t true for every extreme weather event, though. There is enough evidence to show that global warming has increased the number of hot days.
Potential causes of flooding
Local conditions like topography and how wet the soil is contribute to the flood development.
Eg, drier soils are more capable of absorbing most of the rainfall in comparison to wetter soils – however, both really dry and really wet soils can’t absorb much water.
Weather patterns also have a significant role.
A case in point is the 2022 Australian floods. Much of the eastern coast of the country was inundated due to persistent heavy rainfall.
Deforestation: It is another ingredient in the occurrence of floods.
Trees firmly hold soil, and their roots are known to absorb excess surface water, channelling it to underground reservoirs.
Without many trees in an area, the natural blockage that prevents the unchecked flow of water goes away, leading to floods.
Inadequate maintenance of infrastructure may cause floods too.
In Libya’s port city of Derna, the severity of floods was so huge because heavy rainfall caused two of the city’s dams to burst – they collapsed under the pressure of water gathered behind them during the storm.
Several reports have suggested that the dams may have been in a dilapidated state due to the negligence of authorities.
Human encroachment into floodplains is one more reason for flooding, according to experts.
A committee was recently set up to look into the causes for flood Yamuna region of Delhi,
The committee found that the main reason behind the deluge was due to excessive encroachment.
Conclusion
Recent flood disaster in Libya is an eye-opening message for the global community. Therefore, collective actions need to be taken to combat the climate change while developing the disaster resilient infrastructure as per Sendai framework.
