Climate Change: Effects on Health & Human Development

Learning intention: Understand the impact of global trends—specifically climate change—on health and human development.
Success criteria: Ability to analyse how global trends (rising sea levels, changing weather patterns, more extreme weather events) affect health status and each dimension of human development.

Climate change = long-term shifts in temperature, precipitation and weather events prompted chiefly by human activity.
Key anthropogenic contributors:
- Burning of fossil fuels (coal, oil, gas) → $\uparrow 20\%$ atmospheric $\text{CO}_2$ , methane, other greenhouse gases (GHGs) in last 50 yrs.
- Energy production accounts for $\approx 75\%$ of global GHG emissions; majority from transport & industry.
- Additional sources: large-scale agriculture, deforestation, lifestyle patterns (consumption, waste).
Greenhouse effect metaphor: GHGs act like a thermal “blanket,” trapping solar heat and driving global warming beyond Earth’s natural cycles.

Planet has warmed $\approx 1.0^\circ C$ since $1850$ ; every decade is warmer than the last.
Long-term projection (business-as-usual trajectory): $\Delta T \approx 3.5^\circ C$ .
Resultant macro-phenomena:
- Rising sea levels.
- Changing weather patterns.
- Increased frequency & intensity of extreme weather events (floods, cyclones, heatwaves).

Any response must FIRST link climate change to one of the three macro-phenomena (rising sea levels, changing weather patterns, extreme events), THEN analyse consequences for health & human development.
Where appropriate, mention both positive and negative impacts (though positives may be scarce).

WHO forecast $2030\text{–}2050$ : climate change could cause $\approx 250\,000$ additional deaths/yr from malnutrition, malaria, diarrhoea & heat stress.
Population at risk: $3.3\text{–}3.6\,\text{billion}$ people living in climate-vulnerable contexts.

Average sea-level rise $1961\text{–}2003$ : $1.8\,\text{mm/yr}$ .
Recent acceleration: $3.5\,\text{mm/yr}$ ⇒ $3.5\,\text{cm/decade}$ .
Two primary drivers:
1. Thermal expansion of warmer ocean water.
2. Melting of polar ice sheets & glaciers.
Projected displacement: $150\text{–}200\,\text{million}$ people may need to relocate if emissions persist.

> $50\%$ of humanity lives within $60\,\text{km}$ of a coastline.
Low- & middle-income countries (LMICs) especially vulnerable—limited resources for adaptation (e.g., sea walls, resettlement infrastructure).
Stressors: loss of villages/farmland, cultural identity erosion, economic destabilisation.

Salt-water intrusion into underground aquifers and freshwater springs—primary global freshwater reservoirs.
Desalination = technically feasible but $\uparrow$ capital & maintenance costs; unaffordable for many LMICs.
Creates widespread water scarcity → hydration issues, hygiene compromise, agricultural constraints.

High salinity soils inhibit growth of staple seeds, grains, fruits, vegetables.
Warmer oceans => higher acidity → damages coral reefs & marine food chains; jeopardises communities dependent on fish/seafood.

Biodiversity underpins soil fertility, water purification, disaster resilience, medicinal resources.
Rising seas & soil salinity interrupt delicate ecosystems → threatens sustainability of life-support systems.

Water-borne disease uptick (diarrhoea, giardia, cholera) due to contaminated or scarce water.
Mental health strain: anxiety, depression from forced migration & livelihood loss.
Reduced self-esteem & social disconnection from job/income loss & fractured networks.
Infrastructure stress (housing, sanitation, healthcare) → weakened immunity, more injuries.
Education disruption: children miss schooling during relocation → limits knowledge & capability formation.
Curtailment of choices & employment opps lowers income → hampers ability to secure food, health care, safe shelter.

Weather pattern: stable weather state over days/weeks; linked to four seasons.
Oceans modulate weather; elevated sea-surface temps alter rainfall, temperature, seasonal rhythms.
Extreme events intensify as atmospheric water vapour increases with warming: storms, cyclones, heatwaves, floods, droughts, bushfires.

Year $2022$ : $387$ reported climate-related disasters causing significant morbidity, mortality & billions in economic loss.

Degraded water supplies → cholera, algal blooms.
Reduced agricultural yield → malnutrition & diarrhoeal disease.
More allergens → respiratory illnesses (asthma, allergies).
Changing vector ecology → spread of malaria, dengue, Lyme disease into new latitudes.
Increased heat → heatstroke, cardiovascular stress, mortality.
Higher air pollution levels (wildfire smoke, ozone) → asthma, heart disease, premature death.
Severe events → injuries, fatalities, PTSD, depression.

Heatwaves: body unable to dissipate heat → heart failure risk, especially in older adults.
Pollen surges in hot spells → thunderstorm asthma episodes.
Wildfire particulate matter (>10\times\ normal) → acute & chronic respiratory issues.
Nutrient dilution in crops (rice, wheat) under $\text{CO}_2$ fertilisation → lower protein, zinc, iron, B-vitamins → child stunting, higher $\text{U5MR}$ .
Mosquito proliferation in warmer, humid climates → escalation of malaria & dengue transmission, including to previously temperate regions.

Psychological trauma, grief, and loss of purpose after bushfires, floods, droughts.
Breakdown of social networks; reduced civic participation & decision-making influence.
Increased gender inequality: caregiving burdens on women, disrupted small-business activity.
School interruptions for children; employment loss for adults → $\uparrow$ poverty.
Limited access to fundamental resources (food, water, shelter) prevents people “from leading long, healthy, creative lives and from participating fully in society.”

Climate change is not solely an environmental issue—it is a profound public-health emergency and a barrier to equitable human development.
Ethical dimensions: disproportionate burden on LMICs, coastal & Indigenous communities, children, elderly, and women, raising questions of climate justice and intergenerational equity.
Practical imperatives:
- Invest in mitigation (renewable energy transition, reforestation, sustainable agriculture).
- Strengthen adaptation: resilient infrastructure, early-warning systems, climate-smart health services, social safety nets.
- Integrate climate considerations into development policy to safeguard gains in life expectancy, education, equality, and standard of living.