Context: According to the Global Water Monitor Report 2024, climate change has been wreaking havoc on Earth’s water cycle by disrupting how water circulates between the ground, oceans and atmosphere.
Relevance of the Topic: Prelims: Water Cycle; Global Water Monitor Report 2024.
Water Cycle
- It involves the continuous circulation of water in the Earth-atmosphere system.
- There are many processes involved in the water cycle, the most important are evaporation, transpiration, condensation, precipitation, and runoff.
- Although the total amount of water within the cycle remains essentially constant, its distribution among the various processes is continually changing.
- Most water cycles through the planet because of the energy from the Sun and changes in temperatures.
- The water cycle is crucial as it not only enables the availability of water for all living organisms but also regulates weather patterns on the Earth.
Components and Processes of the Water Cycle
| Components | Processes |
| Water storage in oceans | Evaporation, Evapotranspiration, Sublimation |
| Water in the atmosphere | Condensation, Precipitation |
| Water storage in ice and snow | Snowmelt runoff to streams |
| Surface runoff | Stream flow, freshwater storage, infiltration |
| Groundwater storage | Groundwater discharge springs |
What is Climate Change?
- Climate change refers to long-term shifts in weather patterns and average temperatures on Earth, primarily caused by human activities, such as the burning of fossil fuels, deforestation, and industrial processes.
- Characterised by: Increase in greenhouse gas emissions, particularly carbon dioxide, which traps heat in the Earth's atmosphere and leads to global warming.
- Impacts: Rising temperatures, changing precipitation patterns, melting glaciers and polar ice caps, sea-level rise, and altered ecosystems.
- Consequences: Far-reaching consequences for human societies, ecosystems, agriculture, water resources, and natural disasters, posing significant challenges to global sustainability and the well-being of future generations.
Global Water Monitor Report 2024
- Report: Global Water Monitor Report – 2024
- Published by: Consortium of researchers from universities and organisations in countries like Australia, Saudi Arabia, China, Germany, Austria, USA, Netherlands and Denmark etc.
Key Global Findings
- Climate change has intensified the water cycle by increasing the rate of evaporation, driven by rising air temperatures. This has resulted in increasing the strength, duration and rainfall intensity of monsoons, cyclones and other storm systems, causing severe flooding across the world.
- Water-related disasters caused major damage in 2024. They caused over 8,700 deaths, displaced 40 million people, and inflicted more than US$550 billion in damages. Flash floods, landslides, and tropical cyclones were the worst types of disasters in terms of casualties and economic damage.
- Both High rainfall and Drought are becoming more extreme. In 2024, months with record-low precipitation were 38% more common than during the baseline period of 1995-2005, while record-high 24h rainfall extremes were 52% more frequent.
- Rainfall records are being broken with increasing regularity. For instance, record highs for monthly rainfall were set 27% more often in 2024 than in the year 2000, and daily rainfall records were set 52% more frequently.
- Global temperatures continue to increase rapidly. Average air temperature over land area hit an all-time high, reaching 1.2°C above the 1995-2005 average. Over 111 countries experienced their warmest year yet, while 34 countries set new maximum temperature records.
- Last year, most of the world’s dry regions experienced ongoing low values of the terrestrial water storage (TWS). However, the values increased in western, Central and Eastern Africa.
- The outlook for 2025 shows increased risks. Seasonal climate forecasts and current catchment conditions signal potential worsening of droughts in northern South America, southern Africa, and parts of Asia. Wetter regions like the Sahel and Europe may face elevated flood risk.
Other Reports Cited
- Nature journal – Study titled ‘Observed poleward freshwater transport since 1970’ (published in 2022) found that climate change had intensified the global water cycle by up to 7.4%.
- The Intergovernmental Panel on Climate Change (IPCC) - In its sixth assessment report in 2021 said climate change will cause long-term changes to the water cycle. This would lead to more frequent and intense droughts and extreme rainfall events, the report added.
Read More: Impacts of Climate Change