A Global Problem with Local Causes and Local Impacts
Greenhouse gases released since the industrial revolution have increasingly altered the chemical composition of the atmosphere, boosting the fraction of infrared radiation that is reflected back to earth and raising the energy in Earth's systems. This extra energy is already changing weather patterns and ocean environments. There are forecasts for major and sometimes irreversible ecological and economic damage which will only increase if carbon emission targets are not met. All species - including ours - will be affected.
Climate change is a global process, but the effects on meteorological phenomena will differ regionally. This page contains a selection of resources that aim to explain the importance of climate change from a local perspective. |
Predicted Effects of Climate Change on the Nelson Tasman Region
The Nelson-Tasman region has been predicted to experience 1-3 degrees increase in temperature over the next several decades, with the biggest increases during summer. It is also likely to experience drier summers and wetter winters. But these are bigger changes of extremes than the averages suggest: the region will have more hot days and fewer frosty days, more heavy rain events and more dry days. The changes will increasingly impact on water supply and quality, agricultural productivity and the health of native bush and forest. It will put pressure on our stormwater systems and increase the risk of flooding. More hot days will impact the health of residents who struggle with high temperatures, as well as allowing the migration of disease-carrying mosquitoes and other invasive species into New Zealand. The loss of cold days causes problems for alpine species, native birds preyed upon by pests like rats, stoats and possums who breed strongly when temperatures increase, and plants that require frost to germinate.
The images below are from NIWA, using Intergovernmental Panel on Climate Change (IPCC) data from 2013. "RCP8.5" refers to the most severe scenario predicted by the IPCC, which is the scenario that observed global temperature has followed in the years since. It is likely that these scenarios underestimate the impact of climate change because they do not incorporate the less-well-understood feedback loops such as: darker, ice-free land and water absorbing more heat and reflecting less sunlight back into space; methane (a greenhouse gas) being released from melting ice and permafrost; and the loss of forest to fires or changes in temperature or rainfall reducing absorption of carbon dioxide from the atmosphere. These feedback loops are predicted to change our climate exponentially.
The images below are from NIWA, using Intergovernmental Panel on Climate Change (IPCC) data from 2013. "RCP8.5" refers to the most severe scenario predicted by the IPCC, which is the scenario that observed global temperature has followed in the years since. It is likely that these scenarios underestimate the impact of climate change because they do not incorporate the less-well-understood feedback loops such as: darker, ice-free land and water absorbing more heat and reflecting less sunlight back into space; methane (a greenhouse gas) being released from melting ice and permafrost; and the loss of forest to fires or changes in temperature or rainfall reducing absorption of carbon dioxide from the atmosphere. These feedback loops are predicted to change our climate exponentially.
Then there's our oceans, absorbing much of the excess carbon dioxide and energy from the atmosphere and therefore becoming more acidic and warmer. Acidification threatens species that calcify (such as making shells) and every species connected to them through the food web. Warmer seas expand, contributing to a rise in sea levels. Rising seas threaten coastal infrastructure, including roads, rail, ports and buildings, especially when combined with storm surges and king tides. You can explore predicted sea-level rises in this interactive map which illustrates the risk to much of Nelson, Richmond and Motueka, for example. They also pose a salination risk to freshwater near the coast. Warmer water is also inhospitable to species that require cooler water and is threatening many marine ecosystems and the species that rely on them (including us and our marine harvesting industries). And the warmer water has more energy and contributes to making more powerful storms as they pass overhead.
The Ministry for the Environment summarises the risks to the Nelson-Tasman region as:
Finally, a 2015 climate change report for the Tasman region can be found here and in 2020 Tasman District Council published the image below.
The Ministry for the Environment summarises the risks to the Nelson-Tasman region as:
- Coastal hazards – There may be increased risk to coastal roads and infrastructure from coastal erosion and inundation, increased storminess and sea-level rise.
- Heavy rain – The capacity of stormwater systems may be exceeded more frequently due to heavy rainfall events which could lead to surface flooding. River flooding and hill country erosion events may also become more frequent.
- Drought – By 2090, the time spent in drought ranges from minimal change through to more than double. More frequent droughts are likely to lead to water shortages, increased demand for irrigation and increased risk of wild fires.
- Disease - There may be an increase in the occurrence of summer water-borne and food-borne diseases such as Salmonella. There may also be an increase in tropical diseases.
- Biosecurity – Climate change could increase the spread of pests and weeds. Warmer temperatures will make pests such as mosquitoes, blowflies, ants, wasps and jellyfish more prevalent in the region. Similarly, crop diseases such as fungi and viruses may penetrate into the region where currently they are excluded by lower temperatures. There may also be a loss of habitat for native species.
- Agriculture – Warmer temperatures, a longer growing season and fewer frosts could provide opportunities to grow new crops. Farmers might benefit from faster growth of pasture and better crop growing conditions. Horticultural crops, such as kiwifruit and wine grapes, are likely to show the greatest gains from higher average temperatures. However, these benefits may be limited by negative effects of climate change such as prolonged drought or greater frequency and intensity of storms.
Finally, a 2015 climate change report for the Tasman region can be found here and in 2020 Tasman District Council published the image below.
More Climate Change Resources
- David Attenborough: ‘The Facts’.
- Greta Thunberg: ‘No one is too small to make a difference’ and a speech
- Tim Flannery: ‘The Weather Makers’, and ‘Atmosphere of Hope: Searching for Solutions to the Climate Crisis’
- Rod Oram: RNZ National just after 11am each Tuesday; regular columns on Newsroom.
- Paul Hawken: ‘Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming’
- Naomi Klein: ‘This Changes Everything ‘
- Lord Nicholas Stern: ‘Why are we waiting: The Logic, Urgency & Promise of Tackling Climate Change’
- Jim Salinger: ‘Living in a Warmer World: How a Changing Climate Will Affect Our Lives’
- Stuff: a good source of regular articles, especially since their decision in 2018 that the issue was too urgent to accommodate climate denial. Expert answers to questions are available on: [email protected]
Changing for Good: Individual Actions on Climate Change by Janet Stephenson | |
File Size: | 88 kb |
File Type: | docx |
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