Climate change is causing higher temperatures, extreme weather such as heatwaves, heavy rainfall events and/or drought, intense tropical storms and sea-level rise. Rising levels of carbon dioxide are increasing ocean acidity. These changes result in many risks to human health that are recognised by world health and science authorities, New Zealand health bodies, and leading medical journals around the world.
Leading medical journal 'The Lancet' describes climate change as the 'biggest global health threat of the 21st century'; but also points out that action to tackle climate change is a big opportunity to improve health and the fair distribution of good health.
Negative health impacts will have the most impact on people that already experience disadvantage and poorer health. Leading health threats globally and in NZ include:
High temperatures and extreme events causing (or worsening) illness and injury (direct impacts).
- Changing patterns of infectious diseases, and water/food shortages or price changes impacting healthy nutrition (biologically mediated impacts).
Risks related to loss of livelihoods, forced migration and conflict (socially mediated impacts).
Figure 8.1, Impacts of Climate Change on Human Health - Injury Prevention and Environmental Health - NCBI Bookshelf (nih.gov)
However, well-planned action to reduce greenhouse gas (GHG) emissions could bring benefits to the health of New Zealanders. It could also help us achieve a fairer distribution of good health for all people.
Health gains are possible for heart disease, cancer, obesity, diabetes, respiratory disease, and mental health, with resultant cost savings for the health system.
This is because some actions to cut emissions impact on factors underpinning good health:
Walking and cycling cut motor vehicle emissions, increase physical exercise, and cuts air pollution. Walking and cycling are inexpensive, so can help those on the lowest incomes access the basics for good health (e.g. work, education, health-care).
- A healthier diet (less red meat, less saturated fat, more fruit and vegetables) helps cut agricultural emissions, and lowers risks for many diseases, including bowel cancer and heart disease.
- Well insulated homes, with clean and efficient heating, cut energy emissions as well as reducing illnesses associated with cold, damp housing (e.g. childhood asthma and chest infections).
The Lancet Report on Health and Climate Change. Authoritative report updated annually and published in leading international medical journal.
The New Zealand Medical Journal paper 'Health and health equity impacts of climate change in Aotearoa-New Zealand, and health benefits of climate action'.
Health Equity and Climate Change
Climate change will have a large impact on health equity - the fair distribution of good health across all people.
The negative health impacts of climate change will hit hardest the people who already experience disadvantage and/or ill-health. In Aotearoa-New Zealand this includes Māori and Pacific people, children, the elderly, those with disabilities, and those on low incomes.
On the other hand, if health equity is kept at the centre of climate policy-making, it is possible to improve health, health equity and the climate simultaneously.
Health and equity impacts of climate change in Aotearoa New Zealand, and health gains from climate action - New Zealand Medical Journal, November 2014
Health Gains from Climate Change Action
World leading medical journal 'The Lancet' is clear that unchecked climate change will be devastating for human health. However, it also points out the tackling climate change could be 'the biggest global health opportunity of the 21st century'. See here.
This is because policies to address climate change can impact on factors that underpin good health. For example
- Infrastructure and policy to encourage walking/cycling cuts motor vehicle emissions and air pollution, and increases physical exercise, allowing health gains for obesity, diabetes, cancer, heart disease, respiratory disease and mental health.
- A healthier diet across the population (more fruit/vegetables, less red meat, less saturated fat) would cut agricultural emissions, and lower risk for many diseases, including cancer and heart disease.
- Well insulated homes, with clean and efficient heating, cuts energy emissions as well as reducing illnesses associated with cold, damp housing.
By keeping health and fairness at the centre of climate change policy we have the potential to make large health gains in NZ, with cost savings for the health sector that could offset some of the economic costs of tackling climate change.