1 UIUC ATMOS 397G Biogeochemical Cycles and Global Change Lecture 1: An Introduction Don Wuebbles Department of Atmospheric Sciences University of Illinois, Urbana, IL January 21, 2003

2 UIUC Course Syllabus Highlights Will use 2 texts plus handouts Biogeochemistry: An Analysis of Global Change, by W. H. Schlesinger, Academic Press, 1997 (required). Earth System Science, by M. C. Jacobson, R. J. Charlson, H. Rodhe, and G. H. Orians, Academic Press, 2000 (recommended). Grading Midterm exam25% Final exam25% Homework10% Class participation20% Special project20% Special Project: A research project where you together act as a research team Course schedule

3 UIUC Why Study Biogeochemical Cycles? Number 1 of the Grand Challenges in Environmental Sciences National Academy of Sciences, 2001 “ The challenge is to further our understanding of the Earth’s major biogeochemical cycles, evaluate how they are being perturbed by human activities, and determine how they might better be stabilized.” Major research areas: Quantifying the sources and sinks of the nutrient elements and gaining a better understanding of the biological, chemical and physical factors regulating them. Improve understanding of the interactions among the various biogeochemical cycles. Assessing anthropogenic perturbations of biogeochemical cycles and their impacts on ecosystem functioning, atmospheric chemistry, and human activities. Developing a scientific basis for societal decisions about managing these cycles. Exploring technical and institutional approaches to managing anthropogenic perturbations.

4 UIUC The Carbon Cycle

5 UIUC Why study biogeochemical cycles (cont.) NSF Geosciences Beyond 2000 includes as Primary Challenges Determining how the biogeochemical cycles of carbon, nitrogen, oxygen, phosphorous, and sulfur are coupled. Environmental Science and Engineering for the 21 st Century: The Role of the National Science Foundation February 2000 Lists biogeochemical cycles and carbon cycle terrestrial- atmospheric-oceanic connections as key areas for enhanced research. U.S. Global Change Research Program, which includes DOE, NASA, NOAA, NSF has as a major emphasis to better understand the carbon cycle -- $220M in FY2002

6 UIUC Biogeochemical Cycles Six nutrient elements make up 95% of the biomass mass on earth and form the biochemical foundation for life. Carbon (CO 2, CH 4, CO) Nitrogen (N 2 O, NO, NO 2, NH 3 ) Sulfur (SO 2, COS, H 2 S, H 2 SO 4 ) Phosphorous Hydrogen Oxygen

7 UIUC CO 2 Concentration Growth since 1958

8 UIUC

9 UIUC Increasing Carbon Dioxide The Natural Carbon Cycle (Pg-C = Gton-C, Pg-C/yr) The Human Perturbation (for 1980s)

10 UIUC Mann et al. (1999) 1000 year reconstruction ~ 0.7 o C (~ 1.3 o F) increase in global surface temperature during last 140 years (IPCC, 2001)

11 UIUC Radiative Forcing on Climate

12 UIUC Projected Global Surface Temperature Response: ~ 2.5 to 10.4 °F by 2100 Relative to 1990 Projected changes in emissions and concentrations of greenhouse gases could lead to large changes in climate over the century With recent advances in climate model’s ability to represent the earth-atmosphere system, there is now a wider range in potential global and hemispheric-level change due to the range in possible emission scenarios than the range in model results

13 UIUC Length of growing season projected to continue to increase

14 UIUC From Randy Kawa

From Terry Root

16 UIUC

17 UIUC Methane trend From NOAA CMDL

18 UIUC

19 UIUC From Jon Foley

20 UIUC