Discuss about the Climate Change Economics and Policy.
Climate change refers to the change in the global pattern which occurs due to changes in various parameters such as temperature, pressure, precipitation etc. While, climate change also happens automatically due to changes in solar exposure and the atmospheric composition, but these changes are very slow. However, the climate change issue that we face today is caused by humans and hence referred to as anthropogenic climate change. The primary evidence of this is the increase in the carbon dioxide levels since industrialisation which has already reached alarming levels (CSIRO, 2014). This increased level of carbon dioxide in the atmosphere is leading to higher temperature and global warming. This is summarised in the graph shown below.
This carbon dioxide rise is primarily the result of unabated usage of fossil fuels since the beginning of the industrialisation. In the past, the climate change was nowhere as rapid as what has been taking place in the modern industrialised world. Further, since industrialisation the carbon dioxide levels have risen by about 45% i.e. from 280 ppm to 406.15 ppm which has led to an imbalance of the carbon cycle. This leads to accumulation of carbon dioxide in the atmosphere since the natural sinks are unable to absorb the carbon dioxide produced in so abundant quantities which in turn is and causing climate change (IPCC, 2013). The global efforts with regards to addressing climate change through treaties such as Kyoto Protocol are also testimony to the fact that the problem of climate change is indeed created by humans due to which efforts are being made to curb the greenhouse gases emission.
The summary of the observed changes is presented below.
There has been a stark increase in the events comprising of extreme climate or weather since 1950. Additionally, there have been significant alterations in the global precipitation distribution and patterns. Since the advent of industrialisation, there has been an increase in the land and sea temperatures. Due to rise in temperature, there has been sizable melting of ice caps in both the Arctic and Antarctic regions. The melting ice has led to a rise in the mean sea levels by 0.17 m. The melting snow coupled with changing precipitation has led to alterations in distribution of hydrological resources. This in turn has had tremendous influence on the flora and fauna which are dependent on the availability of water. Some species of fishes that have not been able to adapt to this change in water quantity and quality have become extinct. Additionally, there has a marked increase in the incidence of floods and droughts due to alteration of precipitation and also global warming. Due to changes in climate, the food security is under threat as the crop patterns and yields are altering (IPCC, 2013).
As a result of the climate change, there has been an increase in temperature by 0.90 C over the last 100 years. There has been an increase in the incidence of extreme fire weather. Further, the number of days and nights when extreme heat is observed has seen a surge. Also, there has been an increase in the average rainfall but in different parts of the country, the change is variable. While the northwest region, average rainfall has increased, but in the southwest region, there has been a decline in average rainfall (CSIRO, 2014).
Scientists tend to use mathematical models which simulate the various possible scenarios based on which they are able to model the interactions between the various biotic and abiotic components and hence predict the exact extent of change. Since, the modern day climate is driven to a large extent by anthropogenic activities, hence the estimated future climate projections are also driven by the extent of emissions of greenhouse cases by humans. The fifth assessment report by the IPCC captures the likely climate scenarios through the use of RCP (Representative Concentration Pathway). These RCP’s tend to capture the concentration of four major greenhouse houses based on the trends and quantity of emissions which in turn is driven by the level of socio-economic development. There are four estimated levels namely RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 which are all driven by the amount of emissions. Further, for each of these emissions scenarios, the change in global temperature in the future has been modelled considering various realistic assumptions (IPCC, 2013). Thus, this provides a sneak into the possible rise in temperature in the future based on the different emissions level.
The potential future impacts and consequences of climate change are summarised below.
Due to increase in temperature prompted by continued global warming, it is expected that there would be significant rise in sea levels and hence coastal zones that are low lying along with small island states would be adversely impacted. There would be increased risk of flooding in the interior parts leading to loss of life and property. Also, the extreme weather events are expected to continue as the imbalance in natural cycles continues to worsen up. There is high risk with regards to loss to biodiversity due to lack of adaptation and loss of habitat for flora and fauna. This is especially true for coastal and marine ecosystems. Further, the agricultural productivity would be adversely impacted due to growing unpredictability with regards to temperature and precipitation pattern which would fuel food insecurity (IPCC, 2013).
The agricultural activities in the Murray-Darling basin would be severely impacted with the exact amount of impact depending on the extent of mitigation. There would be loss of precious biodiversity in the Great Barrier Reef due to the coral bleaching on a wide scale. Also, the rise in temperature would cause deaths due to persistent heat waves especially in the interiors. Additionally, there would be loss of coastal wetlands and the buildings in the coastal areas can be adversely impacted. Further, the incidence of various diseases contracted through contaminated food and water would rise due to increase in extreme weather events (Garnaut, 2008).
CSIRO 2014, The Report - State of the Climate 2014, CSIRO Website, Available online from https://www.csiro.au/en/Research/OandA/Areas/Assessing-our-climate/State-of-the-Climate/2014-SoC-Report (Accessed on August 5, 2016)
Garnaut, R 2008, The Garnaut Climate Change Review, University of Queensland, Available online from https://www.uq.edu.au/u21/docs/papers/Garnaut%20Climate%20Change%20Review.pdf (Accessed on August 5, 2016)
IPCC 2013, Climate Change 2013: The Physical Science Basis, IPCC Website, Available online from https://www.ipcc.ch/report/ar5/wg1/ (Accessed on August 5, 2016)