1. Climate science in a world with global change David Noone Program in Atmospheric and Oceanic Sciences Cooperative Institute for Research in Environmental Sciences University of Colorado, Boulder, CO

2. Global change Changes to atmospheric composition (greenhouse gases, aerosols, …) Changes to surface conditions (deforestation, agriculture, urbanization, water use) 1. How does climate system (atmosphere, ocean, cryosphere, biosphere) respond? What processes (physical, chemical, biological) govern change? 2. Cloud processes, global hydrologic cycle, atmosphere-biosphere interaction

3. Research to quantify global change Models of climate (and global environment) Observed trends Use of (mostly physical) models to understand impacts on chemical and biological systems What are the feedbacks/couplings between physical-chemical-biological systems? Are these different during Earth’s history (e.g., Ice ages? Warm periods?)

4. Radiative forcing of climate

6. Terrestrial ecosystem/biosphere change Terrestrial biosphere/atmosphere interaction  Not just “response” Identification and quantification of feedbacks between atmosphere and terrestrial biosphere  Specifically water and carbon cycling in the presence of total energy balance Role of ecosystem change and resource use (e.g, logging, water use/availability) on surface energy balance  temperature, humidity, “wetness” Role of global circulation in modifying surface processes  Succession of plant species, further modification of land surface) Possible sustainable states in the climate system  What is, and what limits, the global climate and ecosystem change?

7. Models of atmosphere/biosphere connections water cycle linked to carbon cycle and vegetation

8. Global dimming? CO2 CO 18 O Reconstructed annual reflectance anomalies from earthshine Palle et al., Science, 2004 Coincidence? Or could this be a biospheric signal? Sunlight reflected by earth tends to make dark side of the moon brighter. Brighter moon means dimmer earth.

9. Motivation for global change science Perceived need for research in global environmental change drives funding for research Without global change, climate science would be far more poorly funded! There is a real conflict of interest in the scientific community: catastrophic conclusions lead to more funding! Is global change science objective?