The Science: Climate Change
WHAT IS IT?
Earth's atmosphere is composed of oxygen, a significant amount of nitrogen, and a small percentage of greenhouse gases. These greenhouse gases act like a blanket around the Earth, trapping warmth from the sun and making life on Earth possible. Without them, too much heat would escape, causing the planet's surface to freeze. However, increasing the concentration of greenhouse gases in the atmosphere leads to more heating and climate change.
This process is often referred to as global warming, but it is more accurately described as climate change, as it encompasses various aspects of climate alterations, not just temperature. More extreme climate events such as floods, storms, cyclones, and droughts are likely to occur. There is substantial evidence for climate change, including direct temperature measurements, melting land and sea ice, ocean temperature changes, alterations in rainfall patterns, shifts in the ranges of some plants and animals, and changes in seasonal timing. Other indicators include rising sea levels, increasing frequency of heatwaves, more intense wildfires, and changes in ocean acidity.
What Influences Warming?
It is true that climate change has been driven by natural causes in the past. Our climate has undergone many changes over millions of years — from ice ages to tropical heat and back again. Natural changes over the past 10,000 years have generally been gradual which has enabled people, plants and animals to adapt or migrate, although some prehistoric climate changes may have been abrupt and are likely to have led to mass extinction of species.
However, over the past 150 years there has been a marked and growing increase in greenhouse gas producing activities such as industry, agriculture and transportation. These activities are increasing the level of greenhouse gases in our atmosphere and causing the Earth not only to heat up, but to heat up at an unprecedented rate.
Aotearoa’s Climate
Our local climate is changing. We’re now seeing more severe weather events, droughts and flooding. The Ministry for the Environment provides national reporting on the state of Our Atmosphere and Climate 2020, the latest emissions data in New Zealand's Greenhouse Inventory and changes in the Aotearoa’s emissions over the years with the emissions tracker.
Adapting to Change
Past and current emissions are locking in changes to our climate, such as increased temperatures, sea level rise and extreme weather events. The first national climate change risk assessment for Aotearoa was published 2020, which gives a national picture of how New Zealand may be affected by climate-change related hazards.
For more about the how the climate in Auckland may change over time, what risks this poses and how this might impact your local community see Tāmaki Makaurau Vision.
There will be times when our leaders need to decide and act to protect and enhance mauri (life force) before everybody is ready. Actions to keep climate change below 1.5°C of warming and to adapt to its impacts may be one of these times. Māori are, and have always been, incredibly resilient and adaptable in navigating change and uncertainty. We find strength in knowing Māori knowledge systems and practice offer a strong foundation for community-based adaption and mitigation actions.
For more about how you can increase your resilience or adapt to climate impacts see Tāmaki Makaurau Vision.