The CARBON CYCLE AND GREENHOUSE EFFECT

1. TheCARBON CYCLE AND GREENHOUSE EFFECT

2. The cycling of matter in ecosystems • Energy flows but nutrients cycle. The molecules in an organism will eventually be found in another organism. • Recycling is fundamental for sustainability • Prevents accumulation of wastes • Guarantees that the ecosystem will not run out of essential elements.

3. The basic pattern of nutrient cycles • Autotrophs absorb elements from the inorganic reserve and convert them into organic compounds • Consumers obtain the elements in organic form by feeding on autotrophs or other consumers • Dead organic matter containing the elements are released when organisms excrete or egest waste material or they die. Saprotrophs and decomposers feed on dead organic mater and release the elements in an inorganic form.

4. On the chemical level, the cycle of growth, reproduction, death, and decay of organisms is a continuous process of taking atoms from the environment, assembling them into living organisms (growth), disassembling them (decay) and repeating the process.

5. The Carbon Cycle

6. Thegreenhouseeffect Atmosphere and weather

7. The atmosphere and weather atmospheric structure

8. Weather • Solar radiation

9. Climate • Average temperature and precipitation expected throughout a typical year in a given region • Major changes in climate are a major threat to the structure and function of ecosystems

10. Climates in the past • Annual mean global surface atmospheric temperature • Periods of cooling and warming • General increase in temperature

11. Oceans and Atmosphere • Oceans have an innate heat capacity • Thermohaline circulation • Conveyor system • Affect the density of seawater • One cycle is competed in 1000 years • Heinrich events • Fresh water in the oceans can change climate

12. Global climatechange

13. Global climate change • Factors that influence the climate include: • Internal components • Oceans, the atmosphere, snow cover, sea ice • External factors • Solar radiation, Earth’s rotation, slow changes in our planet’s orbit, and the gaseous makeup of our atmosphere

14. Radiative forcing: the influence a particular factor has on the energy balance of the atmosphere – ocean – land system. • Factors can either be positive (warming) or negative (cooling)

15. Warming processes • Infrared radiation and the greenhouse effect

16. Warming processes • Greenhouse gases (GHGs) • Water vapor • Carbon dioxide • Methane • Nitrous oxides • Ozone • CFCs

17. Cooling processes • The planetary albedo • Clouds • Snow and ice • Volcanoes • Sulphate aerosols • Ozone depletion • Solar variability (11 year cycle)

18. So… • Global atmospheric temperatures are a balance between positive and negative forcing from natural causes (volcanoes, clouds, natural GHGs, solar radiation) and anthropogenic causes (sulfate aerosols, soot, ozone depletion, increases in GHGs)

19. Carbon dioxide as a greenhouse gas • Svante Arrhenius: “differences in CO2 levels in the atmosphere could greatly affect Earth’s energy budget”; he believed this change would be beneficial. • Charles Keeling, 1958, first measures of CO2 levels in Hawaii.

20. Carbon dioxide as a greenhouse gas Sources of CO2 emissions from fossil fuel burning • Carbon dioxide • Sources: • Fossil fuels • Burning of forest trees • Industrial processes • Sinks • Oceans • Terrestrial ecosystems

21. Global carbon cycle Atmosphere – ocean exchange 92 (+/-0,6) Atmospheric CO2 750 6,6 Combustion 90 Oceanic dissolved inorganic carbon Surface – 1020 Depths - 38100 Fossil fuel carbon 4130 62,4 (+/-0,8) Photosynthesis 61 Respiration Terrestrial biosphere Living – 600 – 1000 Dead - 1200

22. The Precautionary Principle • “When there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation” • Principle 15 of the 1992 Rio Declaration – The Precautionary Principle • TAS 189

23. The precautionary principle applied to the greenhouse effect • The UN Framework Conventionon Climate Change made the case in 1992 that: Parties should take precautionary measures to anticipate, prevent or minimize the cause of climate change and mitigate its adverse effects. Where there are threats of serous or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures.

24. The impact of global warming on arctic ecosystems. • Permafrost melts • Matter decomposes • Carbon dioxide is released • Loss of habitat • Food chains disrupted

25. http://changeiness.com/el-nino-more-dangerous-than-la-nina.htmlhttp://changeiness.com/el-nino-more-dangerous-than-la-nina.html • http://soficp-english2.blogspot.com/2010/12/climate-change.html • http://www.sciencephoto.com/media/231041/enlarge • http://www.sciencephoto.com/media/231041/enlarge • http://cosmetica-organica.com/tag/pangea • http://www.cdli.ca/courses/sci1206/unit01_org03_ilo02/b_activity.html • http://www.solcomhouse.com/ozone.htm • http://www.theresilientearth.com/?q=content/more-water-vapor-woes-climate-modelers • http://www.endoftheworld2012.net/globalwarming.htm • http://www.nowpublic.com/environment/polar-bear-sitting-tundra-without-snow-signs-global-warming-0