Lecture 09

February 4, 1997


REVIEW OF FLUX RATE MEASURES



I. THE GLOBAL CARBON CYCLE

* THERE HAS BEEN A GENERAL INCREASE (OF 1.5 PPM PER YEAR) IN THE CONCENTRATION OF CARBON DIOXIDE IN THE ATMOSPHERE OVER THE LAST 30-40 YEARS:

		 YEAR	    Concentration
	      10,000 bce = 	190 ppm
		    1800 = 	290 ppm (Industrial Revolution)
		    1958 = 	315 ppm
		    1988 = 	350 ppm
		    1991 = 	355 ppm
		    1996 @	360 ppm

* IT IS ESTIMATED THAT 58% OF THE CARBON DIOXIDE RELEASED FROM FOSSIL FUEL ENTERS THE ATMOSPHERE.

* THE FATE OF THE REMAINING 42% IS NOT COMPLETELY KNOWN, BUT IT IS EXPECTED THAT THE OCEANS PLAY A MAJOR ROLE, AND FORESTS MAY PLAY A SECONDARY ROLE (Biomass Increase).


    	EMISSIONS				CHANGES

fossil				
fuel 		forest 	    atmosphere	      ocean	    ?
release    +	loss    =   increase     +    uptake   -   sinks
 
5.5		3.2	      1.6		2	    1.9
(75%)		(25%)