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CLIMATE CHANGE

CLIMATE CHANGE. THE GREAT DEBATE. Session 1. IS CLIMATE WARMING?. There is tremendous short term variation in climate This means that we need long-term records to show a warming trend Most long-term records are from stations that are located in cities

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CLIMATE CHANGE

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  1. CLIMATE CHANGE THE GREAT DEBATE Session 1

  2. IS CLIMATE WARMING? • There is tremendous short term variation in climate • This means that we need long-term records to show a warming trend • Most long-term records are from stations that are located in cities • Since the beginning of the industrial revolution cities have experienced rapid increases in local warming from heat generated by industrial, domestic and transport sources • Can we trust such records?

  3. BELIEVERS AND SCEPTICS • Believers say that we are seeing the onset of very rapid climatic warming that is being caused by the emission of large amounts of greenhouse gases and that urgent action is required to deal with it • Sceptics say that climate is always changing and that the present rate of change is not unusual compared with others in recent history

  4. AUSTRALIAN BELIEVERS • Dr Berry Pittock is a climatologist with CSIRO and author of the book: Climate Change – turning up the heat • Dr Tim Flannery is a zoologist who has recently retired as Director of the South Australian Museum. He is a prolific author and has written the book: We are the Weather Makers

  5. Tim Flannery in full flight!

  6. AN AUSTRALIAN SCEPTIC • Ian Plimer is a geologist and professor at the School of Earth & Environmental Sciences at the University of Adelaide. • He is author of the book: Heaven and Earth (Global warming: the Missing Science). • He has received many honours and has always been heavily involved in the mining industry. He even had a mineral named after him: plimerite

  7. CLIMATE CHANGE – A POLITICAL FOOTBALL? • The Australian Labour Party strongly supports the believers and has introduced the Carbon Tax in an attempt to rein in the ever growing use of fossil fuels • The Liberal Party, supported by the mining industry, strongly opposes the introduction ofsuch atax and frequently quote the work of Ian Plimer who denies that human activities are responsible for climate change

  8. WHAT TO BELIEVE? • Much of the temperature increase since 1880 may be due to growing urban heat islands • Not all recent temperature changes can be due to CO2 increase in atmosphere because temperatures dropped between 1940 and 1970 while CO2 content was increasing

  9. Climate at Puntas Arenas shows a cooling trend Why should that be?

  10. WHAT HAPPENED? • Why has thetemperature in Punta Arenas cooled between 1888 and 2004 while world temperatures appear to have been rising? • Could temperature changes in the Southern Hemisphere be out of phase with the Northern Hemisphere? • If Punta Arenas is getting cooler why are the glaciers in the Antarctic Peninsula retreating rapidly?

  11. Three rural stations in New York state also show a decline in mean annual temperature between 1930 and 2000 But what about New York City?

  12. The climate in New York City is getting warmer!

  13. PARADIGM • What is a paradigm? In science, the word describes distinct concepts or thought patterns in any scientific discipline (Wikipedia) • The vast majority of climate scientists subscribe to the paradigm that any increase in greenhouse gases in the atmosphere causes climatic warming

  14. WHAT ARE GREENHOUSE GASES? • The earth radiates long-wave (infrared) radiation and some of that radiation is intercepted by certain gases in the atmosphere and stored as heat energy • Naturally occurring greenhouse gases are water vapour, carbon dioxide and methane. • Carbon dioxide and methane concentrations have increased dramatically since the beginning of the industrial revolution

  15. CARBON DIOXIDE • Large amounts of carbon dioxide are produced by the burning of fossil fuels such as coal, oil and natural gas • Burning of natural vegetation has also made a significant contribution • Concentration in the atmosphere has increased from 280 ppm(v) in 1800 to 392 ppm(v) in 2012 • Seasonal changes aredue to variations in vegetation activity in the Northern Hemisphere

  16. METHANE • Methane is produced in swamps, by grazing animals, burning fossil fuels, wet rice cultivation and decomposition of organic matter in landfills • Concentration in the atmosphere has increased from 700 ppb(v) in 1800 to 1840 ppb(v) in 2012 but the increase has slowed since about the year 2000 • It is a more powerful greenhouse gas than carbon dioxide but breaks down slowly in the atmosphere

  17. A TEMPLE FOR BELIEVERS • The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for the assessment of climate change established by UNEP and WMO to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts (their words)

  18. IPPC • It is a scientific body. It reviews and assesses the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climatic change. It does not conduct any research nor does it monitor climate related data or parameters • Currently 195 countries are members

  19. GOVERNMENT SUPPORT • By supporting the IPCC financially most governments can be seen to be doing something about climatic warming without necessarily making hard decisions such as introducing a carbon tax which would impact on the standard of living of their populations • Australia is one of the few exceptions but it produces only 1.3% of the world’s carbon dioxide emissions and it remains to be seen whether the tax will be effective

  20. PREDICTING CLIMATE CHANGE • Computer models use the latest super computers to try and predict climatic warming over the next few decades • Sceptics point out that these models are a far cry from the complexity of the real Earth especially as they vary only the input of greenhouse gases and neglect the effects of many other processes that affect the Earth’s climate over time

  21. PAST CLIMATE CHANGE • By studying past climate change we can expect to improve our understanding of the multitude of processes involved and how they may effect the Earth’s climate in the future • We will look at three different time scales: total Earth history, the Quaternary Ice Age and the Holocene

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