Questions people ask about water, climate change and disasters

This is the third edition of ‘Questions people ask’, where we answer some of the most common queries we receive.

In September, we looked at water scarcity, and then wastewater in October.

This time, we focus on the topics of water, climate change and disasters.

These interconnected issues have become more prominent, mainly due to increased media coverage of extreme weather around the world – from intense heat and cold, to floods, droughts, storms and fires.

Your questions reflect a growing concern about the water-related impacts of climate change on people’s lives, particularly in poor communities.

At the same time, we are seeing that people are motivated to take action – asking how to protect water and what can be done to build resilience against the effects of a more extreme and erratic climate.

So, here are the most common questions people ask us:

How is climate change affecting water?

Water and climate change are inextricably linked. The impacts of climate change are most acutely felt through impacts on the water cycle and water-related extreme events. Climate change is altering our water cycle, accelerating it, and making it more erratic.

As global temperatures rise, an increased amount of water is evaporating, leading to intensified heavy rainfall in certain regions, while leaving other areas dry. Climate change is therefore resulting in an uneven distribution of water, making it less accessible and more difficult to predict and manage.

To cope with an uncertain future, decision makers will need to adopt resilient water management techniques and technologies.

The top four water-related impacts of climate change:

1. Rising sea levels cause saline water to intrude from the ocean into the freshwater systems in estuaries, and into the surrounding soils, disrupting agricultural activities and harming ecosystems.
2. Flooding can have devastating effects on essential infrastructure and services vital to daily life, particularly water-related facilities. Inundation can damage waterpoints, wells, toilets and wastewater treatment facilities – leaving people without the basic services vital to daily life and survival.
3. Shrinking glaciers, ice caps and snow fields fundamentally alter meltwater flows, which feed river systems in many parts of the world, with half of the world's population relying on water from mountains. This melting will lead to an initial increase in water availability, but over time the reduced volume of glaciers and snow fields will diminish the water supply, affecting people, ecosystems, irrigation systems and hydropower generation.
4. Droughts lead to shortages in drinking water, food production and energy supply, causing health risks and financial losses. Prolonged droughts can force people to leave their homes, creating social and political challenges. Droughts also lead to wildfires, loss of biodiversity, and damage to ecosystems.

If there is more flooding and ice is melting, how can there be water scarcity?

The quick answer is that ‘natural’ water abundance does not automatically mean there is enough safe water for people to drink and use. The devastation of water and sanitation systems in Pakistan after the catastrophic floods of 2022 shows how water scarcity can actually be made worse by an excess of water in the environment.

Rainwater, floodwater and meltwater must be captured and processed to become available to people. In every part of the world, no matter the climate, what is needed are safely managed, effective and resilient water supply infrastructure and systems. Where those systems are absent or ineffective, people struggle to access safe water.

Why are water-related disasters getting worse?

With each additional degree of global temperature rise, the water cycle accelerates and makes water-related disasters worse. ‘Flash droughts’, as well as ‘flash floods’, are becoming more extreme and are happening faster.

Additionally, degradation of natural environments, loss of natural ‘buffers’ such as trees, river bank-side vegetation, wetlands and coastal mangroves reduce protection from flooding.

Rapid urbanization can concrete over large areas of land, channelling run-off too rapidly into storm drains, quickly overwhelming the system and leading to catastrophic flooding of streets and subways.

What is being done to protect water from climate change?

“Making development sustainable, responding to climate change, and reducing the risk of disasters – all are about managing water more effectively.” Gilbert F. Houngbo, Chair of UN-Water

At the UN 2023 Water Conference in March, the first of its kind in nearly 50 years, the United Nations laid out a double-edged approach to water and climate change: by adapting to the water effects of climate change, we will reduce risks, protect health and save lives. And, by using water more efficiently, we will reduce greenhouse gases from water supply and treatment systems.

Here is a small selection of stories from the UN system and our partners around the world:

• The ‘Water at the Heart of Climate Action’ initiative – using local knowledge and global technology to help communities manage water-related risks before they become disasters. (WMO)
• Increasing resilience to flood and drought through ecosystem-based adaptation in Thailand’s rivers. (UNEP)
• Water-smart greenhouses in Uzbekistan saving natural resources while boosting incomes. (FAO)
• Cities in Colombia, Mozambique and Sri Lanka using nature-based solutions such as wetlands and mangroves to become more resilient to climate change. (World Bank)
• Conserving water and making irrigation more efficient in the Yellow River basin in China. (Global Water Partnership)
• The Freshwater Challenge is a country-led initiative to restore 300,000 km of degraded rivers and 350 million hectares of degraded wetlands by 2030. (Freshwater Challenge)

What can I do to conserve and protect water?

Using less water in our daily lives has two impacts. One, it relieves pressure on water resources, which are being put under increasing stress by climate change. And two, it reduces the amount of energy used by water treatment and supply systems and therefore lowers greenhouse gas emissions.

So, through our water usage, we can all play a part in adapting to and mitigating climate change.

Here are five simple water actions:

1. Use water responsibly: Two-thirds of the global population experience severe water scarcity during at least one month of the year (Mekonnen and Hoekstra). Efficient use of water in households – particularly in washing, cleaning and watering gardens – is an easy and effective way to save this precious resource.
2. Eat more plant-based meals: Dietary changes, featuring plant-based foods and sustainable animal-sourced food, could reduce greenhouse gas emissions by up to 8.0 gigatonnes a year of carbon dioxide equivalent (IPCC).
3. Don’t throw away edible food: It takes between 2,000 and 5,000 litres of water to produce a person’s daily food (FAO). Reducing your food wastage reduces demand on agriculture, which is one of the biggest water consumers.
4. Turn off tech: Currently 90 per cent of power generation is water-intensive (UN). By powering down our devices when we’re not using them, less energy needs to be produced.
5. Shop sustainably: It takes around 7,500 litres of water to make a single pair of jeans (UN). Buying less and sourcing our goods from responsible sources can have a big impact on water resources.

Key facts on water, climate change and disasters:

• Water is the medium through which societies experience the most severe impacts of climate change. Water resources management and water supply and sanitation services have remained notoriously underfunded. Yet, a number of water management interventions include aspects of both mitigation and adaptation. Connecting water to climate change funds would allow countries to leverage additional financing resources (UNESCO).
• From 2000 to 2020, floods and droughts killed more than 166,000 people worldwide and inflicted damages in the magnitude of hundreds of millions of dollars (UNESCO).
• Water-related disasters have dominated the list of disasters over the past 50 years and account for 70 per cent of all deaths related to disasters caused by natural hazards (World Bank). Infrastructure has been particularly affected by water-related disasters.  
• Since 2000, flood-related disasters have risen by 134 per cent compared with the two previous decades. Most of the flood-related deaths and economic losses were recorded in Asia. The number and duration of droughts also increased by 29 per cent over this same period. Most drought-related deaths occurred in Africa (WMO).
• Glaciers are retreating in every Andean country, in South America. The most rapid retreat is in the Tropical Andes, in lower-altitude glaciers (UNESCO).

This article was updated on 24 November, 2023.