Flood|| Climate change|| Extreme Weather|| UPSC Current Affairs

Description

CLIMATE CHANGE AND FLOODING

Disclaimer: Copyright infringement not intended.

Context:

Severe flooding has forced tens of thousands to evacuate their homes as wide regions of Austria, the Czech Republic, Poland and Romania have been hit by days of heavy rainfall.

How does climate change affect precipitation?

Water cycle:

The ability of the air to hold water depends on its temperature, hot air holds more moisture, while cooling saturated air forces water out in the form of precipitation, which is the most important phenomena for global water cycle.

Impact of climate change on this cycle

Greenhouse gases released into the atmosphere trapping heat and causing temperatures to rise.
Air’s capacity to hold moisture rises by 7% with every rise of 1 degree Celsius.
Current climate models indicate that rising temperatures will intensify the Earth’s water cycle, by increasing rapid evaporation of water on land and at sea.
This leads to more water to release when it rains and when a huge amount of rain is dumped onto earth in a short space of time, this can lead to flooding.
Temperature rises also make more precipitation fall as rain instead of snow which can make high altitude regions vulnerable to flooding and landslides.

Instances of above normal rainfall and flooding directly linked with Climate Change.

A 2022 study found that in snowy, high-elevation parts of the Northern Hemisphere, rainfall extremes increased by an average of 15% per 1 degree Celsius of warming.
In 2023, Europe was around 7% rainier than normal.
Heavy or record-breaking precipitation triggered floods in Italy, Norway, Sweden and Slovenia.
1 in 4 record rainfall extremes in the last decade can be attributed to climate change.
The floods that devastated western parts of Germany, as well as Belgium and the Netherlands, in 2021 have been directly linked to climate change.
Climate change made rainfall between 3% and 19% stronger and 1.2 to nine times more likely.
More recently, Brazil’s floods in April and May are believed to have been made twice as likely to occur and up to 9% heavier due to the burning of fossil fuels.

Peoples who are likely to face the challenge

Since 2000 the proportion of people exposed to floods is estimated to have increased by 24%.
Today, 1.8 billion people are directly exposed to one-in-100-year floods.
A term used to describe a flood that is so severe it will likely only be equaled or exceeded on average once a century.
In Europe, Germany has the highest number of people at risk of flooding, followed by France and the Netherlands.
An estimated 89% of people exposed to high flood risk live in low- and middle-income countries. Most live in South and East Asia, with 395 million exposed people in China and 390 million in India.
According to one study, the number of people living in areas with a very high flood risk has risen 122% since 1985 due to rapid urbanization, particularly in middle- and low-income countries.

Consequences predicted by UN’s International Panel on Climate Change (IPCC).

Globally, at a 5C temperature rise, which the world is increasingly close to hitting, heavy precipitation that would have been a once in a 10-year rainfall event will occur 1.5 times every decade and be over 10% wetter.
According to the IPCC, at 2 degrees Celcius of warming above pre-industrial levels, what would have been a once-every-10-year rainfall event will occur 7 times per decade and be 14% wetter.
If the world warms to 4 degrees Celcius, heavy rains that used to hit once a decade could hit almost three times more often and release 30% more rain.
In Europe alone, if no adaptation measures are taken and temperatures rise to 3 degrees Celsius, by 2100, floods could rack up €48 billion of damages per year and triple the number of Europeans exposed to flooding.

Way forward

Prepare for extreme weather events: Everyone – governments entities at all levels, business, civil society, individuals - need to be prepared to face more extreme weather events as the climate continues to change at an increasing pace.
Climate change resilient infrastructure : Climate science must be taken into serious account in how to build, adapt and protect homes, communities, businesses and infrastructure through climate change resilient infrastructure.
Decarbonization: Most urgently, greenhouse gas emissions must be reduced, so that rising global temperatures can be controlled while this is still possible and must set targets and timelines for decarbonization.
Nature-based climate solutions : Nature-based climate solutions, such as reforestation and land restoration should be considered, as they can both reduce the impacts of extreme weather events and absorb CO2.