Global climate change facts


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Global climate change facts

  1. 1. GLOBAL CLIMATE CHANGE-FACTS By: Dr. Vinay Kumar Pandey Ph.D., M.Sc. (Geology), M. Sc. (Disaster Mitigation) E-mail: 1 05/03/2013
  2. 2. CLIMATE CHANGEClimate change is asignificant and lastingchange in the statisticdistribution of weatherpatterns over periodsranging from decades tomillions of years. 2 05/03/2013
  3. 3. CAUSES OF CHANGE IN GLOBAL CLIMATE• Change in Earth Orbit• Variable Solar Radiation/Output• ALBEDO (Reflectivity) Effects• Greenhouse effects 3 05/03/2013
  4. 4. 1. CHANGE IN EARTH ORBIT- MILANKOVITCH CYCLES• The concept of Milankovitch Cycles was developed by the Serbian mathematician Milutin Milankovitch (1930). They take account of three variations in the orbit of the earth around the sun.• Earth orbit changes from being nearly circular to slightly elliptical. This cycle affected by other planets in the solar system.• The angle of tilt of the earth axis changes from 22.1⁰ to 24.5⁰.• The direction of the tilt of the axis changes (precession) on a cycle of 26,000 years.These changes define the sequence of ice ages and warm periods. 4 05/03/2013
  5. 5. These changes influence the length of the seasons and theamount of solar radiation received by the earth and5 define the 05/03/2013sequence of ice ages & warm ages.
  6. 6. 2. VARIABLE SOLAR RADIATIONIt appears that our Sun does not transmit a constantintensity of radiation: observations indicate a variability of0.1-0.2%. If solar output decreases for a period of time, itcauses cooling on Earth.Although sunspot activity is cyclical (22 years), we do notcurrently have an accurate concept of how solar outputhas changed (and will change) on longer time scales. 6 05/03/2013
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  9. 9. 3. ALBEDO EFFECTS It is defined as the ratio of  Hence, periods when polar reflected radiation from the ice becomes very extended surface to incident radiation upon it. will promote further It may expressed as a cooling. percentage, and is  Dust in the atmosphere has measured on a scale from the same effect: it forms a zero for no reflecting power high albedo veil around the of a perfectly black surface, Earth, so that much solar to 1 for perfect reflection of radiation is reflected before a white surface. it reaches the surface. The Ocean water have low dust may come from dry albedo whereas land masses climate periods, volcanic have moderate albedo. The highest albedo is snow and eruptions or other means. ice (very light in color). 9 05/03/2013
  10. 10. ALBEDO EFFECT 10 05/03/2013
  11. 11. REFLECTED PERCENTAGE 11 05/03/2013
  12. 12. 4. GREENHOUSE GASSES The greenhouse effect is a  Greenhouse gases reduce the process by which thermal net radiation loss and radiation from a planetary stabilized the average global surface is absorbed by temperature. atmospheric greenhouse  Without this effect, the Earth gases, and is re-radiated in would be cold and all directions. inhospitable. If there is no greenhouse  Main greenhouse gases & their gases, the earth would be percentage on earth are: radiate energy into space  Water vapor, 36-70% and average global  Carbon dioxide, 9-26% temperature would be (-)  Methane, 4-9% 15⁰C.  Ozone, 3-7% 12 05/03/2013
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  14. 14. PLATE TECTONICS AND GREENHOUSE EFFECTS Huge volume of Carbon dioxide are injected into the ocean and atmosphere during plate tectonic activities as earthquake and volcanoes. The annual transported of carbon to & from the land surface & the atmosphere and the ocean & the atmosphere is estimated 120 GtC (Gigatonnes of Carbon) & 90 GtC respectively, and total natural emission is 210 GtC. The annual emission of Carbon dioxide to the atmosphere resulting from human activity is, by comparison, about 7 GtC (about 3% of total natural annual emissions from the biosphere and the ocean). Change in the natural transport of carbon, as well as human activity, have led to recent increases in atmosphere concentration of carbon dioxide. 14 05/03/2013
  15. 15. Natural CO2 emission sources 15 05/03/2013
  16. 16. EVIDENCES OF PAST GLOBAL CLIMATE CHANGES  There is no single instrument measuring climate change. Instead there are thousands of measuring devices spread across the globe, on land, under the sea and in the air.  Physical evidence for and examples of climatic change:1) Temperature measurements and proxies 7) Precipitation2) Historical and archaeological evidence 8) Dendroclimatology3) Glaciers 9) Ice cores4) Arctic sea ice loss 10) Animals5) Vegetation 11) Sea level change6) Pollen analysis 16 05/03/2013
  17. 17. VARIATION OF TEMP. AND CARBON DIOXIDE IN EARTH LIFE CYCLEThis graph indicates that there is no direct relationship between CO2 percentage in the 17 05/03/2013atmosphere and global temperature. CO2 was much higher in past.
  18. 18. Co2 concentration Temperature graph18 05/03/2013
  19. 19. Graph indicates recent year relation between global climate change, CO2 percentage and Sunspots. 19 05/03/2013No direct relation of CO2 in global climate change.
  20. 20. .Graph indicates that temperature varies as Solar irradiance change. Presently Solar 20 05/03/2013Irradiance is decreasing so global temp should be low.
  21. 21. CLIMATE VARIAION IN THE LAST MILLION YEARSWarm age & Ice age is natural cycle. Previously earth was comparatively warm and 21 05/03/2013 cold as per current climate.
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  23. 23. NINE FACTS ABOUT CLIMATE CHANGE -RAY EVANS (Nov 2006) Fact 1. Climate change is a constant. The Vostok Ice Cores show five brief interglacial periods from 415,000 years ago to the present. The Greenland Ice Cores reveal a Minoan Warm Period 1450-1300 BC, a Roman Warm Period 250-0 BC, the Mediaeval Warm Period 800-1100AD, the Little Ice Age and the late 20th Century Warm Period 1900-2010 AD. Fact 2. Carbon dioxide is necessary for all life on earth and increasing atmospheric concentrations are beneficial to plant growth, particularly in arid conditions. Fact 3. The twentieth century was almost as warm as the centuries of the Mediaeval Warm Period (1450-1300 BC), an era of great achievement in European civilisation. The recent warm period, 1976-2000, appears to have come to an end and astro-physicists who study sunspot behavior predict that the next 25-50 years could be a cool period similar to the Dalton Minimum of the 1790s-1820s. 23 05/03/2013
  24. 24.  Fact 4. The evidence linking anthropogenic (man-made) carbon dioxide emissions and current warming is limited to a correlation which holds only for the period 1976 to 2000. Attempts to construct an holistic theory in which atmospheric carbon dioxide controls the radiation balance of the earth, and thus determines average global temperatures, have failed. Fact 5. The anthropogenists claim that the overwhelming majority of scientists are agreed on the anthropogenic carbon dioxide theory of climate control; that the science is settled and the debate is over; and that scientific sceptics are in the pay of the fossil fuel industries and their arguments are thus fatally compromised. These claims are an expression of hope, not of reality. Fact 6. Anthropogenists blame, anthropogenic emissions of CO2 for high temperatures, droughts, melting polar ice caps, rising sea levels and retreating glaciers, and a decline in the polar bear population. 24 05/03/2013
  25. 25.  Fact 7. They also blame anthropogenic CO2 for blizzards, unseasonable snow, freezing weather generally and for hurricanes, cyclones and other extreme weather events. There is no evidence at all to justify these assertions. Increasing atmospheric concentrations of carbon dioxide will have negligible impact on the earth’s radiation balance and will promote plant growth everywhere. Fact 8. Tropical diseases such as malaria and dengue fever are not related to temperature but to poverty, lack of sanitation and the absence of mosquito control practices. Fact 9. The decarbonisation of the worlds economy would, if attempted, cause huge economic dislocation. Any democratic government which seriously sought to fulfill decarbonisation commitments would lose office. Shutting down coal-fired power stations and replacing them with renewable energy sources such as windmills or solar panels will cause unemployment and economic deprivation. 25 05/03/2013
  26. 26. SOLAR CYCLE AND GLOBAL TEMPARATURE The sun turns through 180 degrees every 11 years and our earth orbit comes close to the same parts of the sun that it came close to 11 years earlier. The graph below shows the solar-cycles in global temperatures reasonably clearly. The vertical grid lines are 11-year solar cycle intervals and the solid thin line is the annual mean global surface temperatures, as published by the Australian Bureau of Meteorology. The mean temperature for each 11-year solar cycle interval is shown by the dashed horizontal lines and that value is written in each interval. For example, the last solar cycle from 1999 to 2010 averaged 14.39 degrees C – the hottest 11-year solar cycle since the end of the mini ice age in 1850. (Source: Ian Levy, Jan 2012) 26 05/03/2013
  28. 28. On the basis of above graph Solar Cycle and Global Temperature, following results comes out: There appears to be a strong, solar-related cyclical pattern in global temperatures. Why can’t the overall warming trend also be predominantly solar-induced and not human-induced? Human-induced CO2 increased strongly from 1878 to 1911 but global temperatures fell quite strongly for 33 years – this 33 years of non- correlation between human-induced CO2 build-up and falling global temperatures for 33 years cannot be ignored as a minor aberration. Human-induced CO2 increased strongly from 1944 to 1977 but global temperatures did not rise – they actually fell. Again, this 33-year period of non-correlation with CO2 cannot be ignored. If CO2 is the dominant control on global temperatures, why don’t temperatures increase steadily in proportion to CO2 levels rather than in a cyclical manner that seems to be more related to the sun’s seasonal thermal cycles? 28 05/03/2013
  29. 29. Prediction of future global climate ( Decrease in temp) change, on the basis of Milankovit ch Cycles. 29 05/03/2013Past Age Present Time Future
  30. 30. Predicted TempObserved Temp. Observed surface warming graph are differ from predicted temperature graph. Surface temp has been falling since year 2010. 30 05/03/2013
  31. 31. Global average temp increased + 1.44°C Global average temp decreased (-) 0.08°Cfrom year 1983 to 1997. AND CO2 from year 1998 to 2012. AND CO2concentration increased by 343 to 364 concentration increased by 364 to 394ppm. ppm. 31 05/03/2013
  32. 32. CONCLUSION Climate change is a constant feature of Earth. Human-induced CO2 will increase strongly for at least the next 33years as China and India industrialise. If global temperatures do not rise significantly during this next 33-year period, will we conclude that this was a result of political action against “climate change” or will we conclude that it is probably part of a long-term solar cycle? Anthropogenic (man made) activities are not playing major role in present climate change. Intergovernmental Panel of Climate Change (IPCC) data has been confirmed that despite of massive increase in anthropogenic activities CO2, global temperature goes down & it is differ from prediction. There is no direct relation in concentration of Carbon dioxide in 32 05/03/2013 atmosphere and global temperature.
  33. 33. References Nine Facts about Climate Change- Ray Evans, Nov 2006, Published by Lavoisier Group. A Watershed Year for Global Temperature Trends? Update- Ian Levy, Jan 2012. Various Internet sites. 33 05/03/2013
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