33, 000 13, 000 km 3 71, 000 km 3 425, 000 km 3 40, 000 km 3 15, 300, 000 km 3 1, 350, 000 km 3
Carbon Cycling
Nitrogen Cycling
Global Biogeochemical Cycles • 350 -550 billion tons of carbon trapped in microbes • 85 -130 billion tons nitrogen in microbes • 9 -14 billion tons phosphorus in microbes • 85% of the 15 billion tons of nitrogen fixed annually is fixed by bacteria • 50% of oxygen produced by cyanobacteria
Carbon Cycling
Carbon dioxide concentration (ppm) 380 360 340 320 Mauna Loa Observatory, Hawaii