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PLANET EARTH: FRAGILE AND EVER-CHANGING Ashok Sahni INSA Senior Scientist Earth is 4650000000 yrs old; Life 3500000000 yrs, Industrialization.

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Presentation on theme: "PLANET EARTH: FRAGILE AND EVER-CHANGING Ashok Sahni INSA Senior Scientist Earth is 4650000000 yrs old; Life 3500000000 yrs, Industrialization."— Presentation transcript:

1 PLANET EARTH: FRAGILE AND EVER-CHANGING Ashok Sahni INSA Senior Scientist Earth is yrs old; Life yrs, Industrialization 300 yrs

2 Thermal Regime for a Living Planet 121C to-167C Int. Space Stn. VENUS MARS

3 Fate of Earth?

4 Present Day Species Diversity

5 Snowball Earth Cryogenian ca. 650 ma Icehouse earth 250 ma+ Icehouse earth-present Greenhouse earth

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7 Disasters: Common, happening or yet to happen! FREQUENCIES: ANNUAL TO KILO YEARS-SURFACE AND INTERNAL (PLANETARY) STRESSES:- FREQUENCIES: ANNUAL TO KILO YEARS-SURFACE AND INTERNAL (PLANETARY) STRESSES:- droughts, floods, landslides, earthquakes/tsunamis, volcanic eruptions (within record of human civilization) droughts, floods, landslides, earthquakes/tsunamis, volcanic eruptions (within record of human civilization) FREQUENCIES: KILO YEARS OR MORE-SOLAR OR COSMIC FORCING:- FREQUENCIES: KILO YEARS OR MORE-SOLAR OR COSMIC FORCING:- Climate Change-Solar radiations and water budget Climate Change-Solar radiations and water budget CO2/O2 /O3 enhancement and depletion. CO2/O2 /O3 enhancement and depletion. Cometary Impacts: ( note Tunguska 1908, Lonar, India (10kyr), Shoemaker –Levy on Jupiter Cometary Impacts: ( note Tunguska 1908, Lonar, India (10kyr), Shoemaker –Levy on Jupiter Anoxia-relatively sudden decrease in atmospheric O2 Anoxia-relatively sudden decrease in atmospheric O2 Ecosystem collapse-corals, tropical rainforests, large mammal niche etc Ecosystem collapse-corals, tropical rainforests, large mammal niche etc

8 Global Mean Annual Temperature Distributions at 0 & 100 my

9 Long term climate change perspective ( myrs)

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14 Sun unusually active during last 50 years MonthlySunspotnoMonthlySunspotno

15 Sea level rise

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17 Atmospheric O2 & C02 and evolution of life ( greening of the earth) 20.9%PAL O2 6-8% PAL CO2

18 Emiliania huxleyi Cyclic Solar Energy input drives Earth’s Climate and Weather. Greenhouse Gases. Cyclic Solar Energy input drives Earth’s Climate and Weather. Greenhouse Gases. Phyto (nanno)plankton are a powerful Biologic Pump to drastically reduce Greenhouse Gas CO2 Phyto (nanno)plankton are a powerful Biologic Pump to drastically reduce Greenhouse Gas CO2 NASA’s Sea-viewing Wide Field-of- view Sensor (SeaWiFS) can accurately measure Climate Change reflected by Phytoplankton

19 Climate change: ocean current gyre

20 Primrose: Decoration for man: landing pad for an insect!! Adjusted for UV light as seen by insects Dawkins: Greatest Show on Earth: 2009

21 ICEBERGS WILL MELT! BUT… IF YOU WANT TO LIVE IN HARMONY WITH THE EARTH, TRY TO UNDERSTAND IT. NO NEED TO PANIC!!


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