What is climate change?
Solar energy enters our atmosphere as shortwave radiation in the form of ultraviolet rays and visible light. The Earth's surface absorbs some of this energy and heats up. The Earth cools down by giving off a different form of energy, longwave infrared radiation. But before all this radiation can escape to space, greenhouse gases in the atmosphere absorb some of it, which makes the atmosphere warmer. As the atmosphere gets warmer, it makes the Earth's surface warmer, too. In the absence of any atmosphere, the upward radiation from the Earth would balance the incoming energy absorbed from the Sun at a mean surface temperature of around -18°C, 33° colder than the observed mean surface temperature of the Earth, which is 15°C. This process is referred to as the natural greenhouse effect.
The higher concentration of greenhouse gases (like carbon dioxide, methane, and nitrous oxide) in the atmosphere caused by human activities means that more radiation than normal remains trapped in our atmosphere. This creates an enhanced greenhouse effect.Source: http://www.climatechange.govt.nz/science/what-is-climate-change.html
Source: IPCC AR5 Working Group I Report: The Physical Science Basis, 2013.
The IPCC WGI 2013 report states that continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting warming will require substantial and sustained reductions of greenhouse gas emissions.
The following graph shows projected changes in New Zealand's temperature compared to New Zealand's average temperature over the period 1986-2005. It shows that New Zealand has warmed by about 0.9 degrees celsius since 1990 and that New Zealand's temperature is expected to rise by another 0.8 degrees celsius or so above the 1986-2005 average if the world rapidly implements stringent measure to limit greenhouse gas emissions. By contrast, New Zealand's temperature is expected to keep on rising throughout this century - by about 3.5 degrees celsius above the 1986-2005 average - in a high carbon world.
What are some of the projected climate changes facing the Wellington region?
These Wellington region projections are based on data contained in the 2007 IPCC Fourth Assessment Report, downscaled to the regional level by NIWA.The IPCC Fifth Assessment Report was released in stages in 2013/14. Regional downscaling of climate projections from the latest IPCC report is currently being undertaken by NIWA as part of the “Climate Change Impacts and Implications in New Zealand” project. You can see the work on the project web page: http://ccii.org.nz/research-aims/ra1/
1. Increased frequency and intensity of flood damage to settlements and infrastructure
2. Increased damage from wildfires – to ecosystems and settlements, economic losses and risks to human life in many parts of NZ
3. Increasing risks to coastal infrastructure and low-lying ecosystems from continuing sea level rise, with widespread damage if the more severe projections are realised.
What responsibilities does Greater Wellington Regional Council have that relate to climate change impacts in the region?
How are the projected climate change effects likely to impact some of the services carried out by Greater Wellington Regional Council across the region?
Water supply and security
Maintaining regional biodiversity
Biosecurity – regional pest management
Regional land transport
Why develop a Greater Wellington Regional Council Climate Change Strategy?
A changing climate will create both risks and opportunities for the Wellington region. Agricultural productivity could increase in some areas but there is also a risk of drought, and there will be significant costs associated with changing land use activities to suit a new climate. Forests and vegetation may grow faster, but native ecosystems could be invaded by exotic species, and the risk of wildfires will increase. People may enjoy the benefits of warmer winters but rising sea levels will heighten the risk of erosion, salt water intrusion and flooding, increasing the need for coastal protection.
Some communities are already struggling with coastal erosion and inundation risk, and the risks to coastal infrastructure and low lying ecosystems will increase with continuing sea level rise. Increasingly, the evidence strongly suggests that on balance the negative effects of climate change in New Zealand will outweigh the positive.
Councils are responsible for a range of functions & decisions that can affect and are affected by climate change. Ensuring that we have assessed the significance of, and are responding appropriately to, the causes and effects of climate change across our operations requires a strategic approach. The purpose of creating a Greater Wellington Regional Council Climate Change Strategy is to enable such an approach through the development of an overarching document to help align and coordinate climate change responses across regional council activities.
The climate change strategy will review and build on the good work already occurring, raise awareness of climate change drivers and impacts, and help strengthen information-sharing.
The benefits will be:
Mitigation and adaptation - how do we minimise the impacts and adapt to a changing climate?
Mitigation: minimising change
The first imperative of climate change action is mitigation: the reduction of greenhouse gas emissions and the sequestration of carbon through planting trees and preserving forests. Mitigation activities aim to address the drivers of human-induced climate change so that the worst impacts can be avoided. Mitigation is critically important in the long term. But even the effects of aggressive mitigation are not likely to be evident within the next few decades, given that climate change effects resulting from past and current emissions are already “baked in” to the system.
The observed impacts of climate change are widespread and consequential. Climate change cannot be solved through mitigation alone; adaptation planning is also essential to reduce vulnerability to the increasingly severe and pervasive impacts of climate change already occurring.
Adaptation: preparing for change
Section 7 of the Resource Management Act requires that particular regard be given to matters related to climate change. In a local government context, wherever current climate is significant to an activity, hazard, or plan, the impact of a changing future climate should also be considered.
The RMA Quality Planning Resource on Climate Change (2013) states that Councils should explicitly consider whether the effects of climate change have significant implications for:
The effects of climate change can also be integrated into councils’ longer term planning under the Local Government Act, as part of their mandate to meet the current and future needs of communities for good quality local infrastructure, local public services, and performance of regulatory functions in a way that is most cost effective for households and businesses.