1. Global Warming Magdalena Anguelova Ph.D. Student Advisor: Prof. Ferris Webster What is the Global Warming? What is the Global Warming? 5 min.

2. Global Warming 2 of 25 A 100-year Old Question In 1896 the Swedish chemist Svante Arrhenius asked: “Is the mean temperature of the ground in any way influenced by the presence of heat- absorbing gases in the atmosphere?” Philosophical Magazine

3. Global Warming 3 of 25 In 1896 the Swedish chemist Svante Arrhenius asked: The global warming question was opened. A 100-year Old Question

4. Global Warming 4 of 25 Well, more than 100 years later we still have not answered this question. Moreover, it is a hotly debated issue. A 100-year Old Question Uncertainty 10 years have passed since this presentation was made. Today (2011), we have constrained some of this uncertainty.

5. Global Warming 5 of 25 What is Global Warming? Global warming is a greenhouse effect in excess of the natural greenhouse effect.

6. Global Warming 6 of 25 Greenhouse gases An increasing amount of greenhouse gases in the atmosphere causes the excessive warming. The change in greenhouse gas concentrations can be: »Natural; »Man-induced.

7. Global Warming 7 of 25 Human Impact Humans have always changed their surroundings to some degree.

8. Global Warming 8 of 25 However, in the last century our activities have altered the global environment as never before. Human Impact

9. Global Warming 9 of 25 Nitrous oxide (N 2 O) Our daily life adds to the naturally occurring greenhouse gases: Methane (CH 4 ) Carbon dioxide (CO 2 ) Gas Emissions

10. Global Warming 10 of 25 Nitrous oxide (N 2 O) Methane (CH 4 ) Carbon dioxide (CO 2 ) Gas Emissions The changes since the industrial revolution are: 30% 100% 15%

11. Global Warming 11 of 25 Adding More Even worse -- we add unnatural long-lived (100’s of years) greenhouse gases: –this is “bad” ozone, –different from the one in the UV-protective ozone layer high in the stratosphere. »ChloroFluoroCarbons (CFCs), »and Surface Ozone (O 3 )

12. Global Warming 12 of 25 The Statistics U.S. CO 2 emissions, 1995. Greenhouse gas concentrations are projected to double pre- industrial levels by the middle of the next century.

13. Global Warming 13 of 25 The Effect An increased amount of greenhouse gases, however, may disrupt the planet’s heat budget. The global heat budget is balanced in the long run: Incoming sunlight = Earth’s Reflected + Earth’s Emitted

14. Global Warming 14 of 25 Troubled Heat Budget If the amount of CO 2 doubles, the outgoing radiation from Earth would decrease. To restore the balance, an increase in the mean surface temperature of the Earth is required. By 2100 Earth would be 2 - 6 o F warmer, hence... Climate Changes Temperature Precipitation Sea Level Rise

15. Global Warming 15 of 25 The Role of the Ocean A chain of processes removes atmospheric CO 2 and stores it in the ocean depths: »Atmosphere-ocean gas exchange; »Phytoplankton photosynthesis; »Ocean circulation; »Biological pump.

16. Global Warming 16 of 25 The Removed CO 2 The ocean is the greatest reservoir for CO 2. The net carbon uptake by the ocean is about 34% of the carbon put into the atmosphere.

17. Global Warming 17 of 25 Keeling Curve Atmospheric CO 2 concentration, Mauna Loa, HI. l It became an icon of the global warming problem. No doubt, the amount of greenhouse gases increases.

18. Global Warming 18 of 25 Why the Uncertainty Then? Our uncertainty stems from these questions: Is the warming solely man-induced? Is the warming solely man-induced? Or is this a natural variation in climate? Or is this a natural variation in climate? What is the climate change rate? What is the climate change rate? »Slow -- centuries to millennia? »Fast -- decades?

19. Global Warming 19 of 25 Natural Climate Variability The Earth’s climate has always been changing. No doubt, the climate will continue to change. Greenhouse gas concentrations have changed accordingly.

20. Global Warming 20 of 25 If natural climate change is slow: Slow Climate Change »We can find ways to deal with the man- induced warming; »Ecosystems have an opportunity to adjust.

21. Global Warming 21 of 25 »The man-induced warming may initiate even more rapid warming; Fast Climate Change If natural climate change is fast: »Ecosystems will be drastically affected.

22. Global Warming 22 of 25 Study, Study, Study......know past climate changes well....predict future climate changes accurately....understand present climate better. Thus, we need to

23. Global Warming 23 of 25 Actions Everything helps: Observations: Computers: »Ice and sediment cores; »Ship measurements; »Satellite monitoring. »Ocean-atmosphere models; »Chemical-physical-biological models; »Socio-economic models.

24. Global Warming 24 of 25 We have a lot of work to do! Global Warming Concern The End