GLOBAL WARMING

1. GLOBAL WARMING PREPARED BY Ömer Veli Yeşilyurt

2. Global Warming • Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation. • The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005. • Global warming is a result of increasingconcentrations of atmosphericaerosolsthatblocksunlightfromreachingthesurface, has partiallycounteredtheeffects of warminginducedbygreenhousegases. Source: Intergovernmental Panel on Climate Change

3. Is the climate becoming warmer and warmer? • According to the National Academy of Sciences, the Earth's surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades. There is new and stronger evidence that most of the warming over the last 50 years is attributable to human activities. Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases – primarily carbon dioxide, methane, and nitrous oxide. The heat-trapping property of these gases is undisputed although uncertainties exist about exactly how earth's climate responds to them.(source:US-EPA)

4. Global temperature trendNote that these are surface temperatures and mostly overland. The temperature in upper levels may be different, even reversed.

6. What’s the difference between “global warming” and “climate change”?

7. Difference CLIMATE CHANGE is a broader term that refers to long-term changes in climate, including average temperature and precipitation. GLOBAL WARMING is the increase of the Earth’s average surface temperature due to a build-up of greenhouse gases in the atmosphere.

8. Carbon Dioxide (CO2) Fossil fuels (coal, oil, natural gas) How Global Warming Works

9. Why is global warming happening?

10. Burning of Fossil Fuels Pollution from coal, natural gas, and oil Pollution from coal, natural gas, and oil Pollution from coal, natural gas, and oil

11. We Know That Humans are the Cause • There is a direct correlation between the measured human emissions of greenhouse gases, the rise in atmospheric greenhouse gases, and the rise in temperature. The rates of increase in each is unprecedented. • There is a direct correlation between the growth in the human population and the rise in greenhouse gases and temperature. • Computer simulations indicate that only human-caused emissions of greenhouse gases can cause the observed rise in temperature of the atmosphere and other Earth systems (Oceans, Continents and Ice). • No other natural causes can account for the present rapid rise in temperature and CO2. The present rate CO2 increase is about 20,000 faster than natural rates.

12. What cause the temperature of the atmosphere to go up? • Greenhouse Effect • Concentration of CO2 • Feedback Effect • AerosolsandSoot • Solar Variation

13. Greenhouse effect 103 Watt per m3 343 Watt per m3 240 Watt per m3 Source: Intergovernmental Panel on Climate Change

14. Example of the Greenhouse Effect The Sun’s energy passes through the car’s windshield. This energy (heat) is trapped inside the car and cannot pass back through the windshield, causing the inside of the car to warm up.

15. Greenhouse gases • Carbon dioxide (CO2) • Methane (CH4) • Nitrous oxide (N2O) • Hydrofluorocarbons (HFCs) • Perfluorocarbons (PFCs) • Sulphur hexafluoride (SF6) Natural Manmade Source: Kyoto Protocol- Annexure A

16. Temperature, CO2 Concentrations and Carbon Emissions

17. Global Atmospheric Concentration of CO2

18. How is the CO2 increase connected to the global warming? • Physically, via the greenhouse effect. • The connection is usually made via the use of a climate model. • Control run versus scenarios. • If the scenario run results show warmer surface condition than the control, then it is plausible to suspect that the increasing CO2 concentration in the atmosphere may cause warming.

19. Feedback Effect • The climate system is very complicated. A change in one component of the system may cause changes in other components. Sometimes the changes in other components enhance the initial change, then we say that these changes have positive feedback to the system. If the changes result in the reduction of the original change, then they have negative feedback.

20. Both positive and negative feedback processes may exist in the climate system. In studying the global climatic change, we cannot make conclusions based on intuition, but have to take all such possible complicated effects into account. A good climate model would have treated all of them realistically.

21. Example • The main positivefeedback in global warming is thetendency of warmingtoincreasetheamount of watervapor in theatmosphere, a significantgreenhousegas. The main negativefeedback is radiativecooling, whichincreases as thefourthpower of temperature

22. AerosolsandSoot • Aerosolsexert a coolingeffectbyincreasingthereflection of incomingsunlight. Theeffects of theproducts of fossilfuelcombustionhavelargelyoffsetoneanother in recentdecades, sothat net warming has beenduetotheincrease in greenhousegasessuch as methane.

23. Atmosphericsootaerosolsdirectlyabsorb solar radiation, whichheatstheatmosphereandcoolsthesurface. • Atmosphericsootalwayscontributesadditionalwarmingtotheclimatesystem.

24. How is global warming measured?

25. Ice Core Data CO2 Measurements Before 1958 - Antarctica

26. Effects of Global Warming • Rising Sea Level • Increased Temperature • Habitat Damage and Species Affected • Expansion of subtropicaldeserts • Change in theamountandpattern of precipitation • Extreme weatherevents • Speciesextinctions

27. Effects of Global Warming Rising Sea Level Increased Temperature Habitat Damage and Species Affected Changes in Water Supply

28. 2004 1914 Portage Glacier • Alaska Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org

29. Colorado River • Arizona June 2002 Dec 2003

30. Melting ice and rising sea level Ice shelves of the South Pole have partly separated and are collapsing. (NASA) Receding high mountain glaciers

32. Of course the physical environmental change will lead to changes in the biosphere – including our society.

33. Billions of Metric TonsCarbon Goal: Reductions in CO2 Per Year 2007

34. Our Goal Billions of Metric TonsCarbon Produce electricity efficiently Use electricity efficiently Vehicle efficiency Solar and Wind Power Biofuels Carbon capture and storage Gigaton Carbon Reductions in CO2 Per Year 2007

35. What’s being done now to reduce our emissions? Wind Power Solar Power Fuel-Efficiency

36. Simple Things To Do Turn off your computer or the TV when you’re not using it. Take shorter showers. Heating water uses energy. Keep rooms cool by closing the blinds, shades, or curtains. Turn off the lights when you leave a room. Use compact fluorescent bulbs.

37. Simple Things To Do Dress lightly when it’s hot instead of turning up the air conditioning. Or use a fan. Dress warmly when it’s cold instead of turning up the heat. Offer to help your parents keep the air filters on your AC and furnace clean. Walk short distances instead of asking for a ride in the car. Plant a tree. Recycle.

38. 500 lbs. of coal Be Bulb Smart—Use CFLs What’s the difference? Compact Fluorescent Incandescent • 1,430 lbs. CO2 pollution avoided • $30 saved

39. References • Intergovernmental Panel on Climate Change • www.wikipedia.com