human activities and global change
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HUMAN ACTIVITIES AND GLOBAL CHANGE. Agenda: Putting perturber and the perturbed in perspective Mechanisms for human activity - lasting global change connection Our recent magnificent achievement More difficult task ahead Concluding remarks. - PowerPoint PPT PresentationTRANSCRIPT
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 1
HUMAN ACTIVITIES AND GLOBAL CHANGE
In olden days we had to watch our activities for only temporary local scale pollution.
Now we, human being, have become a force that may produce lasting change on global scale!
Agenda:
•Putting perturber and the perturbed in perspective
•Mechanisms for human activity - lasting global change connection
•Our recent magnificent achievement
•More difficult task ahead
•Concluding remarks
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 2
HUMAN BEINGS ARE MINISCULE RELATIVE TO THE EARTH SYSTEM
Earth ~ 6x1024 kg
Ocean ~ 1.4x1021
Atmosphere ~ 5.3x1018
Biosphere ~ 5.6x1016
Humans ~ 6 x1011
Masses (kg) of highly significant trace gasesCO2 ~ 1.6x1015 ; O3 ~ 8.7x1012 ; N2O ~ 1.5x1012; CH4 ~ 5.2x1012
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 3
THE TRACE GASES (O3, CO2, CH4, N2O) HAVE VERY IMPORTANT ROLES
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 4
ABSORPTION OF SOLAR ENERGY BY O2 AND O3 IS VERY IMPORTANT FOR THE BIOSPHERE
It protects the biosphere from harmful ultra violet
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 5
THE TRACE GASES (O3, CO2, CH4, N2O) SERVE AS GREENHOUSE GASES AND KEEP THE EARTH
LIVABLE
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 6
HUMAN ACTIVITIES - GLOBAL CHANGE CONNECTION IS NOW UNDERSTANDABLE
Despite being miniscule (10-13) relative to the Earth system, human can cause lasting and global change if our activities:
• increase greenhouse gases (that have long lifetimes)
• change the stratospheric ozone (that provides UV shield over biosphere)
Following slides show that both are not only possible but are either happening or have happened
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 7
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 8
CO2 IS BIOSPHERICALLY REGULATED AND IS PRONE TO ANTHROPOGENIC PERTURBATION
Amount stored in: billions of tons1. Atmosphere 2,3002. Oceans 130,0003. Earth (mostly in fossil fuels) 40,000Yearly flux billions of tons/yr 1.From biosphere to atmosphere (respiration
and decay of organic material) 602. From atmosphere to biosphere (photosynthesis) 603. From oceans to atmosphere 1004. From atmosphere to oceans 1005. Into atmosphere from Earth’s interior
(volcanoes, hot springs) 0.16. Into new fossils within earth <0.17. Into atmosphere through human’s
combustion of fuels 68. Into atmosphere from newly cultivated soil 2
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 9
ATMOSPHERIC N2O IS SIMILAR TO CO2
Estimated Sources of N2O
(TgN/yr)
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 10
STRATOSPHERIC OZONE IS PHOTOCHEMICAL IN ORIGIN BUT IS REGULATED BY GASES OF
ANTHROPOGENIC ORIGIN
Pristine pre-biological Atmosphere
O2 + solar UV(<200nm) O + O
O + O2 + M O3 +M
O3 + UV (200-300 nm) O + O*
O3 + O O2 + O2
Pre- & post-industrial present times
O* + H2O OH + OH
O* + N2O NO + NO
NO + O3 NO2 + O2
NO2 + O NO + O2
O + O3 O2 + O2 (Catalytic cycle)
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 11
MORE EXAMPLES OF REGULATION BY GASES OF ANTHROPOGENIC ORIGIN
Cycle 2:
Cl + O3 ClO + O2
OH + O3 HO2 + O2
ClO + HO2 HOCl + OHHOCl + solar radiation OH + ClNet: 2O3 3O2
Cycle 3:Cl + O3 ClO + O2
ClO + NO Cl + NO2
NO2 + O NO + O2
Net: O + O3 O2 + O2
Cycle termination:ClO + NO2 ClONO2; HO2+ Cl HCl + O2
CFC + solar UV Cl
CH3Cl + solar UV CH3 + Cl
Cycle 1:
Cl + O3 ClO + O2
ClO + O Cl + O2
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 12
MORE COMPLEX REACTIONS LEAD TO OZONE HOLE IN THE SPRING TIME POLAR REGIONS
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 13
OUR RESPONSE TO OZONE HOLE WAS MAGNI-FICIENT: WHAT ABOUT GLOBAL WARMING?
Year
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 14
GLOBAL WARMING HAS THE POTENTIAL TO PRODUCE SERIOUS CONCEQUENCES
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 15
MANAGING GREENHOUSE GAS EMISSION IS MUCH MORE DIFFICULT
• climate-friendly technologies, commonly referred (Technology Cooperation)
• practices that reduce greenhouse gas emissions and increase carbon sinks (Land Use and Forestry management changes)
Both affect energy that is so fundamental to our society—it powers our homes, businesses, and industries (“bread and butter situation)
No wonder implementation of the Kyoto Protocol to control greenhouse gas emission is proving so much more difficult than the Montreal agreement
3 Oct 2002 Creative Research Enterprises’ PresentationPolytechnic University of Puerto Rico
Slide 16
CONCLUDING REMARK
• Setting aside current fierce debate over seriousness of global warming, sooner or later we have to face the challenge of doing without fossil fuels
• The hope is that we will do it sooner rather than later and thereby be prepared for “what if global warming turned out to be serious?”
At current consumption rate (~4.7 Btons/yr), it will last about 230yrs. Then what?