Understanding Climate Change Risks to Basic Human Needs: Food, Water and Shelter

Climate change isn’t an abstract future threat-it’s actively reshaping the foundation of human survival. The interconnected systems that provide our food, water, and shelter are under increasing pressure from rising temperatures, shifting precipitation patterns, and extreme weather events. Understanding how climate systems influence human security is essential for grasping the full scope of this global challenge.

What is climate and why does it matter for human security? 🔗

Climate refers to the average weather conditions of a particular region measured over at least 30 years, according to the Intergovernmental Panel on Climate Change (IPCC) and World Meteorological Organization. Unlike daily weather fluctuations, climate represents long-term patterns that ecosystems and human societies have adapted to over millennia.

The relationship between climate systems and human wellbeing is deeply interconnected. Temperature, precipitation, and sea level directly influence natural resources like water availability, ecosystem health, and biodiversity. These resources, in turn, determine human security across multiple dimensions: livelihoods, food production, energy access, and health outcomes. When climate stability erodes, social stability often follows-manifesting as migration, resource conflicts, and political instability.

Human security encompasses safety from chronic threats such as hunger, disease, and displacement, as well as protection from sudden disruptions to daily life. Climate change is increasingly recognized as a threat multiplier-it intensifies existing vulnerabilities and creates new ones, particularly in regions already facing political and economic fragility.

The timeline of climate change: from industrial revolution to present 🔗

Earth’s atmosphere began changing significantly during the 19th century with the onset of the Industrial Revolution. The large-scale burning of fossil fuels released unprecedented quantities of greenhouse gases, primarily carbon dioxide, into the atmosphere. This marked the beginning of human-induced climate change.

The IPCC’s Fifth Assessment Report, published in 2013, projected that global mean temperatures could increase by 1.5°C to 4°C by the end of this century, depending on emission trajectories. The 2018 Special Report delivered a more urgent warning: without dramatic reductions in greenhouse gas emissions, the world could see a 2°C increase by mid-century.

The Paris Agreement, adopted in 2015, established the global commitment to limit warming to well below 2°C above pre-industrial levels, with efforts to keep it to 1.5°C. This threshold matters enormously: according to the World Food Programme, a 2°C increase could push an additional 189 million people into hunger, while a 4°C rise could affect 1.8 billion people.

Climate change impacts on food security 🔗

Food production depends fundamentally on stable climate conditions. Crops require predictable rainfall, appropriate temperatures, and consistent growing seasons. Climate change disrupts all of these factors simultaneously.

Droughts, floods, and crop yields 🔗

Extreme weather events are becoming more frequent and severe. Prolonged droughts lead to soil erosion, dried-up grazing lands, and reduced crop yields. Floods and landslides destroy agricultural infrastructure and contaminate water supplies. The U.S. Environmental Protection Agency notes that climate change affects crops, livestock, soil, and water resources-all essential components of food systems.

Research indicates that without robust adaptation measures, climate impacts could reduce major crop yields by approximately 11 percent in coming decades. The situation is particularly acute in regions already facing water stress. The Center for Strategic and International Studies reports that the FAO estimates meeting future agricultural demand under climate change will require 40 to 100 percent more water than would have been necessary without warming.

The global hunger crisis 🔗

Food insecurity has already worsened dramatically in recent years. According to World Bank data, the number of people experiencing acute food insecurity rose from 135 million in 2019 to 345 million by mid-2022, driven by overlapping crises including climate phenomena, conflict, and economic disruptions. Currently, 783 million people face chronic hunger worldwide.

In regions like the Horn of Africa, climate-driven locust swarms have decimated crops, while Pacific Island nations face threats to coral reefs and coastal fisheries from rising temperatures and ocean acidification. These impacts create cascading effects: higher food prices, malnutrition, economic losses, and social unrest.

Water scarcity: the defining crisis 🔗

Water security sits at the heart of the climate-human security nexus. Agriculture accounts for 72 percent of global freshwater withdrawals-the highest of any sector. As climate patterns shift, water availability becomes increasingly unpredictable.

Declining freshwater resources 🔗

Freshwater resources per person have dropped by 20 percent over the past two decades due to a combination of population growth, overuse, pollution, and climate change. Groundwater aquifers, which supply one-third of all water use globally and half of irrigation needs, are being depleted faster than they can naturally recharge.

The World Bank estimates that approximately 1.6 billion people already live in countries experiencing water scarcity-a number that could double within two decades. Climate change amplifies this crisis by altering precipitation patterns, reducing snowpack that feeds rivers during dry seasons, and increasing evaporation from reservoirs and soil.

Competition and conflict over water 🔗

As water becomes scarcer, competition intensifies. This is particularly evident around transboundary water supplies-aquifers, lakes, and river basins shared by multiple countries. In regions like central Mali, diminishing arable land and unpredictable water sources have exacerbated tensions between farming and herding communities. Iraq faces similar pressures, where water scarcity, rising temperatures, and dust storms strain intercommunal relations.

The IPCC has identified water scarcity under climate change as a major challenge for adaptation in many regions. Changes in precipitation, runoff, and groundwater recharge will affect both water quantity and quality, with implications for agriculture, drinking water supplies, and ecosystem health.

Sea level rise: threatening shelter and settlements 🔗

Perhaps no climate impact poses a more direct threat to human shelter than rising seas. Global mean sea level has risen 8 to 9 inches (21-24 centimeters) since 1880, with the rate accelerating significantly in recent decades.

Accelerating rates of rise 🔗

According to NOAA, the rate of sea level rise has more than doubled from approximately 1.4 millimeters per year throughout most of the 20th century to 3.6 millimeters per year between 2006 and 2015. In 2023, global mean sea level reached a record high-101.4 millimeters above 1993 levels. Scientists recorded an unexpectedly fast rise in 2024, with rates exceeding projections.

Two primary factors drive this rise: melting glaciers and ice sheets, and thermal expansion as ocean water warms. Ice loss from the Greenland Ice Sheet increased sevenfold between 1992-2001 and 2012-2016, while Antarctic ice loss nearly quadrupled over the same period.

Coastal populations at risk 🔗

The World Economic Forum reports that rising sea levels now impact approximately one billion people worldwide. Nearly 30 percent of the U.S. population lives in coastal areas vulnerable to flooding, erosion, and storm surge. Globally, eight of the world’s ten largest cities are located near coastlines.

The impacts extend beyond direct flooding. Saltwater intrusion contaminates freshwater aquifers and agricultural land. In Bangladesh, the loss of farmland to increasing salinity is forcing people off lands their families have farmed for generations. The country could see 0.9 to 2.1 million people displaced by sea level rise by 2050.

Asia faces the greatest population exposure due to dense coastal settlements. Bangladesh, China, India, Indonesia, and several other Asian nations account for 70 percent of people exposed to sea level rise during this century. Small island nations like Tuvalu, Kiribati, and Fiji face existential threats, with some projected to become largely uninhabitable by 2100 without intervention.

The displacement crisis 🔗

Climate impacts are already forcing millions to leave their homes. More than 20 million people are displaced annually by hazards resulting from extreme weather events, including heavy rainfall, droughts, desertification, and cyclones. Over the past decade, weather-related disasters caused approximately 250 million internal displacements-averaging over 67,000 per day.

By mid-2025, more than 86 million displaced people were living in countries with high-to-extreme exposure to climate hazards. Projections suggest that 2050 levels of sea level rise could result in roughly 150 million people below the high-tide water line, with about 300 million living in areas that flood annually.

These population movements create complex challenges. Host communities face increased pressure on resources and services, while displaced populations often settle in informal areas vulnerable to additional climate impacts. The cycle becomes self-reinforcing, with climate displacement contributing to urbanization in flood-prone zones.

Disproportionate impacts and vulnerable populations 🔗

Climate change does not affect everyone equally. The poorest and most marginalized communities face the greatest risks despite contributing least to the problem. In low-income countries, large portions of the population depend directly on climate-sensitive activities like farming, fishing, and forestry.

The World Bank has estimated that climate change could push an additional 68 to 135 million people into poverty by 2030. Women and girls face particular vulnerabilities at the intersection of climate impacts and existing inequalities. In Somalia, shifting rain patterns contribute to water scarcity and higher rates of conflict, early marriage, and violence against women. When climate disasters force families to travel farther for water, women and girls face increased risks of violence and reduced opportunities for education and income.

The path forward: adaptation and mitigation 🔗

Addressing climate risks to basic human needs requires action on two fronts. Mitigation efforts must dramatically reduce greenhouse gas emissions-the IPCC indicates that global emissions must fall by 48 percent compared to 2019 levels by 2030 and reach net-zero by 2050. Simultaneously, adaptation measures must help communities cope with changes already underway.

Effective adaptation strategies include improved water management and efficiency, drought-resistant crop varieties, early warning systems for extreme weather, coastal protection infrastructure, and support for climate-displaced populations. Countries like Jordan are investing in water supply infrastructure, while regions across Africa are pursuing initiatives like the Great Green Wall to combat desertification.

The interconnected nature of climate, resources, and human security means that solutions must be equally interconnected. Addressing food security requires attention to water management. Protecting coastal communities involves both infrastructure investment and managed retreat from the most vulnerable areas. Supporting displaced populations requires both emergency response and long-term planning for sustainable resettlement.

What do you think? How might your community be affected by climate-related changes to food, water, or housing systems? What role can local action play in building resilience to these interconnected challenges?

References

1. https://www.ipcc.ch/report/ar5/wg2/human-security/
2. https://www.un.org/en/climatechange/science/climate-issues/human-security
3. https://www.un.org/climatesecuritymechanism/en/united-nations-framework-convention-climate-change-unfccc-and-climate-peace-and-security
4. https://www.wfp.org/climate-action
5. https://www.epa.gov/climateimpacts/climate-change-impacts-agriculture-and-food-supply
6. https://www.csis.org/analysis/water-and-food-how-when-and-why-water-imperils-global-food-security
7. https://www.un.org/en/un-chronicle/water-scarcity-climate-crisis-and-global-food-security-call-collaborative-action
8. https://www.unwater.org/water-facts/transboundary-waters
9. https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level
10. https://www.weforum.org/stories/2025/03/rising-sea-levels-global-threat/
11. https://www.nrdc.org/stories/sea-level-rise-101
12. https://en.wikipedia.org/wiki/Sea_level_rise
13. https://www.unhcr.org/sites/default/files/2025-11/no-escape-ii-the-way-forward.pdf