well, I've done my bit to keep the human race going, but overall Germany produces only half as many babies as it would need to pay the pensions, and the billion-people countries India and China also have new kinds of problems. Read my story "Absent babies in a crowded world" here:

http://www.current-biology.com/content/article/abstract?uid=PIIS0960982206016836

(access to the full text  may require subscription to Current Biology, not sure)