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What Lies Ahead. Thomas C. Peterson NOAA’s National Climatic Data Center Asheville, North Carolina. Outline of the talk:. The basic physics of climate change science Implications of this physics On temperature and precipitation Projected changes relevant to the plant sector
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What Lies Ahead Thomas C. Peterson NOAA’s National Climatic Data Center Asheville, North Carolina
Outline of the talk: • The basic physics of climate change science • Implications of this physics • On temperature and precipitation • Projected changes relevant to the plant sector • A bit on impacts
We need the greenhouse effect • The Earth’s surface temperature is ~60ºF • Without the greenhouse effect it would be ~5ºF • But humans are changing the radiative properties of the atmosphere and thereby the greenhouse effect
Climate Forcing Summary Ravishankara (2006) Warming versus cooling effects are like the tortoise versus the hare.
Do you believe in global warming? • I believe in quantum physics.
Quantum physics tells us that • Infrared (IR) energy can only be absorbed and radiated in very small particle-like packets of energy called quanta
Quantum physics tells us that • Infrared (IR) energy can only be absorbed and radiated in very small particle-like packets of energy called quanta • Each molecule can absorb and radiate quanta at different wavelengths
Quantum physics tells us that • Infrared (IR) energy can only be absorbed and radiated in very small particle-like packets of energy called quanta • Each molecule can absorb and radiate quanta at different wavelengths • Two atom molecules can absorb very little IR energy • E.g., Nitrogen (N2) and Oxygen (O2) • 98% of the atmosphere
Quantum physics tells us that • Infrared (IR) energy can only be absorbed and radiated in very small particle-like packets of energy called quanta • Each molecule can absorb and radiate quanta at different wavelengths • Two atom molecules can absorb very little IR energy • E.g., Nitrogen (N2) and Oxygen (O2) • 98% of the atmosphere • Three or more atom molecules do absorb and radiate in the IR • E.g., Carbon Dioxide (CO2), water vapor (H2O), methane (CH4) • 2% of the atmosphere • CO2 only 0.04% of the atmosphere
Are CO2 and other greenhouse gasses really responsible for changing the global temperature? • Ice cores can give us the long view
Are CO2 and other greenhouse gasses really responsible for changing the global temperature? • The long view says they are definitely related Vostock ice core data from Petit et al., 1999; current CO2 data from NOAA (Tans 2007)
Atmospheric carbon dioxide is predicted to rise to concentrations not seen in perhaps 25 million years • Pekar 2008 GCCI, 2009
Scenarios • Future warming depends on how much greenhouse gases are emitted • Several different scenarios were developed based on possible changes in • Population • Rate of adoption of new technologies • Economic growth • But not policies
Data through 2007 Kaya identity: CO2 emissions from human sources = (population)x(GDP/capita)x(Energy/GDP)x(CO2/energy) Hence 2008 emission likely to be lower than 2007’s. Data for 2008 available in June 2009. GCCI 2009
Not from climate A to climate B • Projections to end of century gives appearance of climate change ending then • Plan for continual change • Where the rate of change is most relevant
Humidity increases are greatest where temperatures are highest Peterson et al., 2011
Temperature increases are highest where humidity is lowest Peterson et al., 2011
As climate warms, hardwood trees out-compete evergreen trees that are adapted to colder conditions GCCI, 2009
Projected Shifts in Forest Types GCCI, 2009 Mid-range warming scenario
Ecosystems processes, such as those that control growth and decomposition, have been affected by climate change. • Climate change has strong influence on the processes that control growth and development in ecosystems • Temperature increases can: • Speed up plant growth, especially weeds • Rates of decomposition • How rapidly the cycling of nutrients occurs Kudzu vines
Climate change is here and now and in our own backyards • In the U.S., spring now arrives an average of 10 days to two weeks earlier than 20 years ago • The growing season is lengthening over much of the continental U.S. • Many migratory bird species arrive earlier Photograph by Robert Lubeck: Animals Animals—Earth Scenes