Climate Change: Adversative Effects on the Weather of Melbourne

1.0 Introduction

Melbourne is Australia’s second-largest city. Its population is expected to increase from 3.7 to 5 million by 2026 and thus it is considered the fastest growing state capital city. In the current millennium, all the metropolitan cities have emerged as a driving force in various forms of subnational climate governance. Planning strategies for the cities have become an important mechanism to attain urban sustainability in this period. A study shows that Melbourne City incorporates critical and important elements in its planning strategies to enhance climate governance. Some of them being; inclusion of promotion of coordination principles, innovative technologies, long term planning scale, etc. This report will further put up various characteristics related to climate change, dedicated to the Melbourne region.

These climate changes are having severe impacts on our environmental systems. It directly impacts on the weather causing heatwaves, extreme storms, floods, bushfires (Adger et. al., 2007). Melbourne has come up with a “Climate Change Adaptation Strategy” in 2009, which is one of its kind in Australia, in which the approach for adapting to climate change was mapped out. In the “Adaptation Action Plan 2010” they put in detail, the steps to be taken in response for the assessment of the risk in climate change (Jones, 2012; Melbourne.vic.gov.au, 2019).

2.0 Change in precipitation

The region of Melbourne has already become a bit warmer and drier from 1950. Rainfall has also gradually declined since the 1950s, especially in autumn, and will continue in this manner if no solution is provided. The summers range from mild to warm, with an average temperature of 22ºC to 24ºC, while winters from 12ºC to 14ºC, reducing the frost days in the inland areas. In the past years, the global surface air temperatures have risen almost by 1ºC, which has led to the regions getting warmer and drier by the coming years. Some of the key reasons for the rise in temperatures and lessening of rainfall are related to human activities that release greenhouse gases. Some of these human activities include, land agriculture, forest depletion and emission of greenhouse gases. Due to these rising temperatures, the frosts days are declining rapidly which in turn are causing more intense and heavy downpours at irregular times. The risk of extreme hot days is doubled in the urban areas due to an effect called as Urban Heat Island. This could lead to a rise of up to 5.6ºC in the urban areas compared to that of the surrounding areas in the city.

The city is working towards understanding the needs of its people and protecting them from the impacts of reduced rainfall and extreme heat. They are investing in infrastructure and working towards satisfying the targets with a smarter use of drinking water and bring flexibility to the increasingly scarce rainfall and drought periods.

The figure below shows an increase in temperatures in various parts of Melbourne as well as a decrease in rainfall since 1950s (Climatechangeinaustralia.gov.au, 2019).

Figure 1.0 Temperature and rainfall changes (Climatechangeaustralia.gov.au, 2019).

3.0 Sea level and humidity

Due to change in climate, it is predicted that there will be an average sea level rise of about 5cm to 15cm by the year 2030 and a rise of 16cm to 47cm in the year 2070 along the coastline of Victoria. The risks of high sea levels are not severe in the immediate future but are very prominent in the years of 2070 with the current climate change projections. Higher sea levels in 2070, with intense storms and high urge storm heights, will greatly affect the coastal and riverine areas to get flooded by storm events (City of Melbourne, 2009).

Long term strategies are more effective to tackle the high sea levels than potentially drastic and urgent steps taken when shores are inundated. The most effective measure which can be taken are while urban planning and infrastructure decisions in short term. Avoiding building strategies that enable to construction in and around inundated prone areas. Engage policies that involve in encouraging landowners to relocate through tax benefits (Melbourne.vic.gov.au, 2019; NCCARF, 2016).

4.0 Wind and temperature

The winds in the Melbourne region are from principle three directions; north, south and west. These differ throughout the year, where the northerly winds are most frequent in the Melbourne region. Southerly and the westerly winds occur during the warmer months and in the winter months respectively. As per the current climate change projections, it is predicted that the temperature of Melbourne region will keep on increasing wherein the hot days will rise by 10 days in 2030 and by 17 days in 2070. Similary, the frost days will decrease to just 1 day in the year 2030 and we will have no frost days in the year 2070 (City of Melbourne, 2009). Increase in temperature will impact the environment, the ecosystem as well as humans. To fight this high temperature, the metropolitans will plan their cities in a sustainable way, incorporate green infrastructure, etc. Watering parks and street trees will contribute in controlling the atmospheric temperature, with the provisions of increasing the passive cooling efficiency inside of the buildings (Adger et. al., 2007; Victoria State Government, 2015).

Figure 2.0 Temperature predictions in Melbourne (Victoria State Government, 2015).

5.0 Social impact on food, water supplies and health

There would be numerous effects on the necessities of humans due to climate change, which could affect the health condition of humans. It is to be noted that with increase in climate change results in a rise in disease-carrying snails and other sorts of bacteria. As per an Australian study it was found that when the temperature rises so does the effect of food poisoning on humans. Furthermore, the water supply and sewage treatments could also be contaminated which would affect the drinking water of humans as these may lead to out bursting diseases such as cholera and diarrhea (Australian Academic of Science, 2019). Another aspect of climate change will be the effect of heat on human health. Some major effects of the heat will be dehydration, heat strokes, renal and cardiovascular diseases. It is estimated that between January and February of 2019, 400 excess deaths were recorded due to the intense heat recorded. These deaths were mostly recorded from Victoria and South Australia (Williams et al. 2019). Henceforth, the impacts on the society and nature could be mitigated by following some of the strategies such as public education, special programs, healthcare, high surveillance of diseases and forecasting on future health risks, disaster preparations and mostly provide early warning systems. Therefore, by implementing some of these methods some fatal diseases that were raised by global warming could be prevented or mitigated (McMichael et al. 2008).

6.0 Future impact of climate change towards year 2030 and 2090

The figure below reflects how Melbourne is tackling and finding solutions for climate change in various ways. They have listed out agendas in which different aspects have been touched such as, enhancing the natural environment, building infrastructure in a sustainable manner, having culturally diverse communities, etc. It built upon multiple principles; leadership, innovation, share knowledge, build partnerships and multiple benefits. Therefore, further research is done about the impacts of Climate Change and the methods used in mitigating them.

Figure 3.0 Mitigations against Climate Change (Melbourne.vic.gov.au, 2019).

6.1 Temperature changes

Increase in temperature has been one of the major impacts of climate change and as per the CSIRO website it is stated that the temperature of Australia has risen by 1.0 C since 1910. It is further revealed that the annual average temperatures will increase 0.4 to 2.0 C over parts of Australia by 2030 and by 2070 these temperature figures will be risen from 1.0 to 6.0 C.

It is revealed through research that cities like Melbourne are subjected to extreme weather, high temperatures, and rising sea levels as a result of these. It is proven from the research that the only remedy for this effect of global warming will be to reduce the emission of greenhouse gases especially in major cities like Melbourne (CSIRO.au, 2019). One of the tragic disasters that will occur mostly in eastern parts of Australia, such as Victoria, due to the rise in temperature will be bushfires. The effect these bushfires has had on the community has increased over the years. Most of all the extreme 10% of fire weather has been recorded in the last few days and this is clearly shown in figure 4.0 (CSIRO.au, 2019). Methods to mitigate or to prevent the rise in temperature will be to stabilize the greenhouse gases or else reduce the GHG layer over the ozone layer. This could then reduce the amount of heat radiated back to earth from the GHG layer, which cause the global temperature to rise (Hijioka et al. 2006).

Figure 4.0 Number of days of bush fire over 25 FFDI (Forest Fire Danger Index) (CSIRO.au, 2019).

6.2 Rainfall

The annual average rainfall in the city of Melbourne is about 660 mm which is evenly distributed across the year (Zhou et al. 2000). With the effect of climate change and rise in temperature will eventually result in an increase in the evaporation of water, causing the atmosphere to carry more gaseous water. It is approximated that with every C of temperature rise causes approximately 6 to 7% evaporation of water (Richard 2011).

This statement was also proven by CSIRO with some calculation projections made about the evaporation of water as this consequently result in decrease in rainfall level. It is predicted that due to global warming the average annual rainfall will decrease from 15 to 160 mm in 2030 and 40 to 500 mm by 2070. The changes to the average rainfall will greatly affect the frequency of the wet and dry seasons. Hence as shown by figure 5.0 the summers become 15% wetter and spring becomes 10% dry which could affect the natural habitat (CSIRO, 2001).

Figure 5.0 The rainfall level in spring and summer (CSIRO, 2001 ).

6.3 Impact on the ecology

Currently, there is a decline in ecosystem services due to the global deforestation and forest degradation and this has led to a massive lost in biodiversity. It is discovered that the global forest land is reducing at a rate of 13 million hectares per year. These are mainly due to the land use and disruption of forests fail to provide a good ecosystem service due to this (Ciccarese, Mattsson & Pettenella 2012). Furthermore, even in terms of coastal floodplains and wetlands it could be seen that there is a massive threat to this ecosystem too due to the rise in sea level caused by global warming. Moreover, other factors that affect the ecosystem, and will be chief threats to Australia’s island, include plant invasion, habitat loss, pollution and hydrological changes (Laurance et al. 2011). Even though, high levels of CO2 have negative effects it still could increase the forest growth by about 25 to 50 percent Nevertheless, this could still be a major threat to some plants in the Melbourne region as they will not have enough water to carry out photosynthesis (Luca &Kirschbaum., 1999).

7.0 Conclusion

The climate change in the current era is having adversative effects on the weather of Melbourne and as stated in this report that these effects occur at a much faster rate. Many factors such as wind speed, global temperature, rainfall level, sea level and solar radiation are some of the adverse effects that could worsen for the future generations. A variety of methods are being implemented by the Australian and the state governments and they are being closely monitored for any sign of progress. Thus, the increase in climate change can be prevented and would improve the lifestyle of the local community while living a sustainable life. Most importantly, if the greenhouse gas emissions could be reduced, these negative effects would be much less impactful and will eventually result in a cleaner and safer environment for everyone.