01
Explore
What is changing in our atmosphere, ecosystems and communities?
GLOBAL HEALTH • CLIMATE & ENVIRONMENT
Climate & Environment
How does a changing planet become a health issue?
Climate change is not only about temperature. It changes the environments in which people live, learn, work and grow — influencing air, water, food, livelihoods, infectious diseases, mental health and access to health services.
GHE Principle
Understand the change. Explore who is affected.
Think about solutions. Act responsibly.
Self
→
Family & Peers
→
Community
→
Country
→
World
YOUR EXPLORATION
Explore → Learn → Think → Connect → Reflect → Act
Climate and health become easier to understand when we connect scientific evidence with the places, people and systems around us.
02
Learn
Understand greenhouse gases, hazards, exposure, vulnerability and resilience.
03
Think
Ask why some people and places face greater risks than others.
04
Connect
Link climate with health, development, economics, nature and society.
05
Reflect
Consider evidence, uncertainty, responsibility and fairness.
06
Act
Identify practical solutions at the personal, community and systems levels.
01 • UNDERSTAND
Climate Change: What Is Actually Changing?
Climate describes long-term patterns of temperature, precipitation, winds and other atmospheric conditions. Climate change refers to persistent changes in those patterns. Human activities — particularly the burning of fossil fuels — are the dominant driver of current warming.
A warming climate
Rising average temperatures change the frequency, intensity and duration of heat extremes.
Changing water patterns
Rainfall, drought, floods and water availability can change across regions.
Extreme events
Heatwaves, wildfires, storms, floods and droughts can create direct and indirect health risks.
Changing ecosystems
Climate pressures interact with biodiversity loss, land-use change and other environmental pressures.
1.44°C
A changing global climate
The United Nations reported in 2026 that the planet is already about 1.44°C warmer than in the late 1800s.
02 • CONNECT
Climate Change Becomes a Health Issue Through Pathways
Climate hazards do not affect health in only one way. They interact with environmental conditions, social circumstances, behaviours and health-system capacity.
1
Climate hazard
Heat, flood, drought, wildfire, storm
→
2
Exposure
Who or what is exposed?
→
3
Vulnerability
Who has fewer protections?
→
4
Health outcome
Illness, injury, stress or disruption
Extreme heat
Heat can worsen cardiovascular, respiratory and other health conditions and can increase the risk of heat-related illness.
Air quality
Climate-related heat, wildfire smoke and other conditions can contribute to harmful air pollution.
Water & food
Floods, droughts and changing environmental conditions can affect water security, food systems and foodborne disease risks.
Infectious diseases
Climate conditions can alter the distribution and transmission patterns of some vector-, food- and water-borne diseases.
Mental health
Disasters, displacement, loss of livelihoods and prolonged environmental stress can affect mental health and well-being.
Health systems
Climate hazards can damage facilities and infrastructure while increasing demand for care.
HEALTH EVIDENCE
Why Public Health Cares About Climate
people already live in areas highly susceptible to climate change, according to WHO.
additional deaths per year were estimated by WHO for 2030–2050 from selected climate-sensitive causes including malnutrition, malaria, diarrhoea and heat stress.
estimated direct annual health damage costs from climate change by 2030, excluding health-determining sectors such as agriculture and water and sanitation.
These are modelled estimates and should be interpreted in their stated context. Climate-health impacts are influenced by exposure, vulnerability, adaptation and future emissions.
03 • SOCIAL DETERMINANTS OF HEALTH
Climate Change Is Also an SDH Issue
Climate hazards do not affect everyone equally. Social and economic conditions shape exposure, vulnerability, access to protection and the ability to recover.
Climate hazard
+
Exposure
+
Vulnerability
+
Limited resources
→
Higher health risk
Income & poverty
Income affects housing quality, transportation, access to cooling, insurance, food security and the ability to recover after climate-related events.
Housing & neighbourhoods
Location, housing conditions, green space, heat exposure and infrastructure can shape environmental health risks.
Education & information
Access to reliable information and education can influence preparedness, risk perception and the ability to act on warnings.
Work & livelihoods
Outdoor workers, agricultural workers and others whose livelihoods depend on environmental conditions may face increased exposure.
Access to health services
Climate hazards can increase health needs while simultaneously disrupting transportation, facilities, electricity and supply chains.
Social support
Strong social networks and community organizations can help people prepare, respond and recover.
LOCAL
What happens here?
Which neighbourhoods, schools, workers or households may face greater exposure?
NATIONAL
What systems matter?
How do housing, health services, infrastructure, emergency preparedness and policy shape resilience?
GLOBAL
Who bears the burden?
How do historical emissions, resources, geography and adaptive capacity shape global differences?
THINK DEEPLY
The Same Hazard Does Not Mean the Same Risk
Two communities can experience the same heatwave, flood or wildfire smoke event but have very different health outcomes.
Community A
- Reliable cooling
- Accessible health services
- Strong early-warning systems
- Safe housing
- Financial resources
- Strong community networks
SAME
HAZARD
Community B
- Unsafe or overcrowded housing
- Limited health-care access
- Weak warning systems
- Outdoor employment
- Financial insecurity
- Limited social protection
GHE Data Question
If two places experience the same temperature increase, should we assume they experience the same health risk?
Think about exposure, vulnerability, resources, infrastructure and adaptive capacity.
04 • CREATE SOLUTIONS
Mitigation + Adaptation
Climate action has two closely connected dimensions: reducing the causes of climate change and preparing for impacts that are already occurring or expected.
Reduce the causes
Mitigation means reducing greenhouse-gas emissions or increasing their removal from the atmosphere.
- Renewable energy
- Energy efficiency
- Cleaner transportation
- Lower-carbon buildings
- Sustainable food systems
- Protection and restoration of ecosystems
Reduce vulnerability
Adaptation means changing decisions, systems and practices to reduce the health and social impacts of climate hazards.
- Heat-warning systems
- Climate-resilient health facilities
- Flood preparedness
- Water security
- Climate-informed disease surveillance
- Community resilience
HEALTH CO-BENEFITS
Climate action can also improve health today
Cleaner energy, active transportation, healthier urban environments and improved food systems can reduce emissions while producing health benefits, particularly through cleaner air and healthier living conditions.
CANADA • YOUR NATIONAL CONTEXT
Climate & Health in Canada
Climate risks vary across Canada's large and diverse geography. Health Canada identifies risks including extreme heat, floods, storms, air pollution, water quality and security, food security, infectious diseases and mental health impacts.
Extreme heat
Heat events can create significant risks, particularly for people who are more vulnerable.
Wildfire smoke
Smoke can affect air quality over large areas, sometimes far from the fire itself.
Infectious diseases
Changing environmental conditions can influence some climate-sensitive infectious diseases.
Water & food
Climate-related hazards can affect water quality, availability and food systems.
Health-system perspective
Adaptation is not simply an environmental task. Health authorities need climate information, preparedness plans, surveillance, resilient infrastructure and community partnerships.
ENVIRONMENT • HEALTH • LIFE
One Planet, Connected Health
Human health depends on functioning environmental systems. Climate change interacts with biodiversity, water, food, air, land and the health of other living systems.
HEALTH
People
AIR
WATER
FOOD
NATURE
CLIMATE
COMMUNITY
13
SUSTAINABLE DEVELOPMENT GOALS
SDG 13 — Climate Action
Take urgent action to combat climate change and its impacts.
Resilience
Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters.
Climate policy
Integrate climate-change measures into national policies, strategies and planning.
Knowledge & capacity
Improve education, awareness, human and institutional capacity on climate change mitigation, adaptation, impact reduction and early warning.
Climate Action Connects to Many Other SDGs
SDG 1 • No Poverty
SDG 2 • Zero Hunger
SDG 3 • Good Health
SDG 4 • Quality Education
SDG 6 • Clean Water
SDG 7 • Clean Energy
SDG 10 • Reduced Inequalities
SDG 11 • Sustainable Cities
SDG 12 • Responsible Consumption
SDG 14 • Life Below Water
SDG 15 • Life on Land
SDG 16 • Strong Institutions
GHE DATA DETECTIVE
Don't Just Look at the Climate Data — Ask Better Questions
A number becomes useful evidence only when we understand what it measures, who it represents, when it was collected and what comparison is appropriate.
01
What?
What variable is being measured?
02
Where?
What geographic area does the data represent?
03
When?
What time period does the measurement cover?
04
Who?
Which populations are represented — and who may be missing?
05
Compared with what?
Is the comparison using the same denominator, period and definition?
06
What does it mean?
What conclusion is supported — and what remains uncertain?
05 • CHECK YOUR THINKING
Climate & Environment — 12 Data & Reasoning Questions
These questions are designed to test interpretation, systems thinking and evidence — not just memorization.
Q1
Which statement best describes climate change as a public-health issue?
Q2
A city experiences the same heatwave as a neighbouring city, but has poorer housing and less access to cooling. What concept best explains why health impacts may differ?
Q3
Which example is primarily climate-change mitigation?
Q4
Which example is primarily climate adaptation?
Q5
WHO reports that about 3.6 billion people live in areas highly susceptible to climate change. What does this number tell us most directly?
Q6
Why is climate change considered a Social Determinant of Health issue?
Q7
A researcher compares heat-related illness between two cities but uses different population denominators. What is the main problem?
Q8
Which statement best illustrates a climate-health co-benefit?
Q9
Which SDG is specifically dedicated to climate action?
Q10
Why might a low-income community experience greater health impacts from the same flood as a wealthier community?
Q11
UNEP's 2025 Emissions Gap Report estimated that current policies could lead to approximately 2.8°C of warming this century. What is the most appropriate interpretation?
Q12
Which question best represents strong GHE climate-health thinking?
GHE REFLECTION
Every difference matters. Explore it.
Climate change is a global challenge, but health risks are experienced locally. Look around you. What climate or environmental change could affect health in your community? Who might be most affected? What evidence would you need before proposing a solution?
Observe
Question
Investigate
Connect
Propose
Act
EXPLORE FURTHER
Trusted Sources
Start with primary and authoritative sources. Climate and health evidence changes as research improves, so always check the date and context of a statistic.