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).                     

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'.