3 Oct 2002 Creative Research Enterprises Presentation Polytechnic 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 Presentation Polytechnic University of Puerto Rico Slide 2 HUMAN BEINGS ARE MINISCULE RELATIVE TO THE EARTH SYSTEM Earth ~ 6x10 24 kg Ocean ~ 1.4x10 21 Atmosphere ~ 5.3x10 18 Biosphere ~ 5.6x10 16 Humans ~ 6 x10 11 Masses (kg) of highly significant trace gases CO 2 ~ 1.6x10 15 ; O 3 ~ 8.7x10 12 ; N 2 O ~ 1.5x10 12 ; CH 4 ~ 5.2x10 12 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 3 THE TRACE GASES (O 3, CO 2, CH 4, N 2 O) HAVE VERY IMPORTANT ROLES 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 4 ABSORPTION OF SOLAR ENERGY BY O 2 AND O 3 IS VERY IMPORTANT FOR THE BIOSPHERE It protects the biosphere from harmful ultra violet 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 5 THE TRACE GASES (O 3, CO 2, CH 4, N 2 O) SERVE AS GREENHOUSE GASES AND KEEP THE EARTH LIVABLE 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 6 HUMAN ACTIVITIES - GLOBAL CHANGE CONNECTION IS NOW UNDERSTANDABLE Despite being miniscule ( ) 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 Presentation Polytechnic University of Puerto Rico Slide 7 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 8 CO 2 IS BIOSPHERICALLY REGULATED AND IS PRONE TO ANTHROPOGENIC PERTURBATION Amount stored in: billions of tons 1. Atmosphere 2, Oceans 130, Earth (mostly in fossil fuels) 40,000 Yearly flux billions of tons/yr 1.From biosphere to atmosphere (respiration and decay of organic material) From atmosphere to biosphere (photosynthesis) From oceans to atmosphere From atmosphere to oceans Into atmosphere from Earths interior (volcanoes, hot springs) Into new fossils within earth < Into atmosphere through humans combustion of fuels 6 8. Into atmosphere from newly cultivated soil 2 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 9 ATMOSPHERIC N 2 O IS SIMILAR TO CO 2 Estimated Sources of N 2 O (TgN/yr) 3 Oct 2002 Creative Research Enterprises Presentation Polytechnic University of Puerto Rico Slide 10 STRATOSPHERIC OZONE IS PHOTOCHEMICAL IN ORIGIN BUT IS REGULATED BY GASES OF ANTHROPOGENIC ORIGIN Pristine pre-biological Atmosphere O 2 + solar UV(