Volume One 19. Climate Change 19. Climate Change Introduction Society will continue to rely on fossil fuels as an energy source for the foreseeable future. The consumption of these fuels results in the release of carbon dioxide and other greenhouse gases into the atmosphere. The general consensus of scientific opinion is that the world is getting warmer, causing its climate to change. Global temperatures are approximately 0.6 degrees Celsius higher now than they were in the early 1990s. While there is not unanimous agreement, there is now strong evidence that most of the warming observed is attributable to increased concentrations of greenhouse gases produced by human activities. As more gases accumulate in the atmosphere, the Earth gets warmer, resulting in rising sea temperatures and levels, the melting of glaciers and ice caps and greater extremes in weather patterns, such as more storms of greater intensity and longer droughts. In Marlborough, NIWA predicts that the mean temperature will increase by approximately 1 degree by 2040 and 2 degrees by 2090. The climate is likely to become drier and the frequency of droughts is expected to increase. There is also a predicted increase in westerly winds, especially in winter and spring. Section 7 of the Resource Management Act 1991 (RMA) requires the Council to have regard to the effects of these predicted climatic changes in exercising its functions under the RMA. Uncertainty about the nature of these effects at international, national and local level makes this a difficult task. Most projections are also long term and certainly beyond the ten year life of the Marlborough Environment Plan (MEP). Taking all of this into account, the provisions of this chapter focus on applying the best available information to enable people and communities to respond to the adverse and positive effects created by climate change. Issue 19A – Climate change has the potential to affect Marlborough’s natural and physical resources and the ability of people and communities to use these resources. Marlborough relies on its natural and physical resources for its social and economic wellbeing and health and safety. The nature of many natural and physical resources and the ability to use them, especially land and freshwater resources, is dependent on climate. This makes Marlborough vulnerable to any long term changes in climate. Primary industry makes a significant contribution to Marlborough’s economy and is vulnerable to changes in climate. Many primary industries rely on sufficient quantities of rainfall or freshwater in rivers and aquifers to supplement rainfall through irrigation. The various crops that are grown or the type of stock that is grazed reflects these climate variables. Predictions of higher temperatures, more extreme temperatures and reduced rainfall could therefore have a significant impact on rural land users through increased risk of drought and decreased water availability. Any decrease in water availability will also increase the competition for freshwater amongst existing users. Marlborough’s natural ecosystems could also be vulnerable to the effects of climate change. Indigenous terrestrial, aquatic and marine species could respond to increased temperatures and drier conditions by shifting to more suitable climatic zones. Any inability to move may have significant consequences for the long term viability of affected indigenous species, especially plants. 19 – 1