Climate Change: The Move to Action (AOSS 480 // NRE 480) Richard B. Rood Cell: Space Research Building (North Campus) Winter 2012 February 14, 2012

Class News Ctools site: AOSS_SNRE_480_001_W12AOSS_SNRE_480_001_W and 2010 Class On Line:2008 and 2010 Class – /Climate_Change:_The_Move_to_Actionhttp://climateknowledge.org/classes/index.php /Climate_Change:_The_Move_to_Action

Some Uncertainty References Climate Change Science Program, Synthesis Assessment Report, Uncertainty Best Practices Communicating, 2009Climate Change Science Program, Synthesis Assessment Report, Uncertainty Best Practices Communicating, 2009 Climate Change Science Program, Synthesis Assessment Report, Transportation Gulf Coast, 2008Climate Change Science Program, Synthesis Assessment Report, Transportation Gulf Coast, 2008 Moss and Schneider, Uncertainty Reporting, 2000 Pidgeon and Fischhoff, Communicating Uncertainty, 2011Pidgeon and Fischhoff, Communicating Uncertainty, 2011 Lemos and Rood, Uncertainty Fallacy, 2010

The Current Climate (Released Monthly) Climate Monitoring at National Climatic Data Center.Climate MonitoringNational Climatic Data Center – State of the Climate: Global Plant Hardiness

Today Observations of Ecosystems Attribution (3 ways?)

Question Madden and Ramanathan Predicted in 1980 would be discernable in 2000.Madden and Ramanathan What would you do to evaluate the theory and predictions of global warming? –Surface of planet will warm –Sea level will rise –Weather will change Think about Measurements Feedbacks Correlative behavior Impacts

Signal to Noise From Leeds X-ray Imaging

Signal to Noise (perhaps more like climate) From social research methods.net

Signal to Noise (another example) From astronomy and astrophysics.org SignalNoise Signal / Noise Ratio

Some signal to noise issues We have many sources of variability –Sun, volcanoes, etc. –El Nino, La Nina, etc. –Ice ages, Little Ice Age, Warm Periods, etc. –Land use changes, natural carbon dioxide variability, etc. –How do we detect a trend in temperature and attribute it to human released carbon dioxide?

Let’s go back to the physical climate

Fig (State of Climate 2009) Time series from a range of indicators that would be expected to correlate strongly with the surface record. Note that stratospheric cooling is an expected consequence of greenhouse gas increases. A version of this figure with full references is available at /.State of Climate / Correlated behavior of different parameters

Today Observations of Ecosystems Attribution (3 ways?)

Edges “Edges” are places where we really might be able to see things definitively. What are the edges? –Ice (Phase transition) –Deserts –Seasons

There is an accumulation of observations Physical and biological impacts correlated with temperature increase and dryer conditions. –What is the relationship between warming and surface dryness? –Strongly correlated with population and where we have looked.

Project Budburst A community science activity collect observations of the onset of spring –Project BudburstProject Budburst How to observe the onset of spring –National Phenology NetworkNational Phenology Network

Project of Trees A community science activity to collect observations on types of trees –Canadian Plant Hardiness SiteCanadian Plant Hardiness Site Paper (including yours truly) on how foresters think about climate change McKenney et al. (2011)

Interestingly significant news story

Hardiness Map Arbor Day Foundation Maps of Hardiness ZonesArbor Day Foundation Maps of Hardiness Zones Plant Hardiness

Can we get a global perspective from satellites? NDVI: Normalized Difference Vegetation Index –Looks at radiative budgets, measurements, and the absorption of photosynthetically active radiation, relative to the rest of the radiation.

How would these changes be revealed?  Changes in vegetation activity can be characterized through 1. changes in growing season 2. changes in “productivity” Increases in Productiviy Increases in growing season JanDecJul Aug Increase NDVI JanDecJul Aug earlier spring delayed fall NDVI From Compton J. Tucker, NASA Goddard

From Kirsten de BeuresKirsten de Beures

Length of Growing Season From Ranga B. Myneni, Boston University

Changes in the Amplitude of the Keeling Curve (Keeling et al, 1996) Amplitude has increased 20% in Hawaii Amplitude has increased 40% in Alaska, Canada The phase, start of the decrease, start of the growing season, has moved forward 7 days.

Geographical extent of warming Osborn Spatial Extent of Warming

Coherent and Convergent? There is evidence in both the physical climate system and ecosystems of systematic global warming. This evidence shows correlated behavior through many systems. Taken independently each piece could be challenged. Taken together the evidence converges. –Consistent with human-related forcing

Coherent and Convergent? Taken independently each piece could be challenged. Taken together the evidence converges. –Consistent with human-related forcing Consistent with human-related forcing –Really?

Today Observations of Ecosystems Attribution (3 ways?) –Fingerprinting –Joint Attribution (end-to-end method) –Event attribution

Attribution The physical climate and ecological observations in the previous are consistent with the planet is warming. How do we decide that this is consistent with human-induced warming?

Natural mechanisms influence climate Changes in the Sun Changes in the amount of volcanic dust in the atmosphere Internal variability of the coupled atmosphere and ocean Natural mechanisms Thanks to Ben Santer for Content!Ben Santer

Human factors also influence climate Non-natural mechanisms Changes in atmospheric concentrations of greenhouse gases Changes in aerosol particles from burning fossil fuels and biomass Changes in the reflectivity (albedo) of the Earth’s surface Smoke from fires in Guatemala and Mexico (May 14, 1998) Thanks to Ben Santer for Content!Ben Santer

Carbon dioxide is the most important greenhouse gas produced by human activities Atmospheric CO 2 has increased from a pre- industrial value of about 280 parts per million (ppm) to ppm in The atmospheric concentration of CO 2 in 2010 exceeds by far the natural range (180 to 300 ppm) over the last 650,000 years Fossil fuel use is the primary source of the increased concentration of CO 2 since the pre- industrial period Recent changes in carbon dioxide are largely human-induced Source: IPCC AR4 (2007) Thanks to Ben Santer for Content!Ben Santer

1.“Basic physics” evidence –Physical understanding of the climate system and the heat-trapping properties of greenhouse gases 2.Circumstantial evidence –Qualitative agreement between observed climate changes and model predictions of human-caused climate changes (warming of oceans, land surface, and troposphere, stratospheric cooling, water vapor increases, etc.) 3.Paleoclimate evidence –Temperature reconstructions enable us to place the warming of the 20th century in a longer-term context 4.Fingerprint evidence –Rigorous statistical comparisons between modeled and observed patterns of climate change Multiple lines of evidence on which “discernible human influence” conclusions are based Thanks to Ben Santer for Content!Ben Santer

Models can perform the “control experiment” that we can’t do in the real world Meehl et al., J. Climate (2004) Average surface temperature change (°C)

Strategy: Search for a computer model-predicted pattern of climate change (the “fingerprint”) in observed climate records Assumption:Each factor that influences climate has a different characteristic signature in climate records Method:Standard signal processing techniques Advantage:Fingerprinting allows researchers to make rigorous tests of competing hypotheses regarding the causes of recent climate change What is “climate fingerprinting”? Thanks to Ben Santer for Content!Ben Santer

IPCC Temperature Observations Note: It gets smoother away from the surface.

Different factors that influence climate have different “fingerprints” 1. Solar 3. Well-mixed greenhouse gases 5. Sulfate aerosol particles 2. Volcanoes 4. Ozone 6. 1 st five factors combined Height (km) Pressure (hPa) °C/century Santer et al., CCSP, 2007

“Fingerprinting” with temperature changes in Earth’s atmosphere Model Changes: CO 2 + Sulfate Aerosols + Stratospheric Ozone Height (km) Pressure (hPa) Observed Changes Temperature changes in o C Santer et al., Nature (1996)

Initial work by Syd Levitus and colleagues showed an increase in the heat content of the oceans over the second half of the 20 th century (Levitus et al., 2001, Science) Subsequent research by Tim Barnett and colleagues identified a human fingerprint in the observed ocean heat content changes (Barnett et al., 2001, Science) Searching for fingerprints of human activities in the world’s oceans Thanks to Ben Santer for Content!Ben Santer

“Fingerprinting” in the ocean: Warming of the North Atlantic over Barnett et al., Science (2005) Thanks to Ben Santer for Content!Ben Santer

“Fingerprinting” in the ocean: Warming of the world’s oceans over Barnett et al., Science (2005) Thanks to Ben Santer for Content!Ben Santer

Fingerprint detection explained pictorially…. Time-varying observed patternsTime-varying control run patterns t=1 t=2 t=3 t=4 t=n t=1 t=2 t=3 t=4 t=n Projection onto model fingerprint Signal and noise time series Signal-to-noise ratios Projection onto model fingerprint Model fingerprint Thanks to Ben Santer for Content!Ben Santer

Human-caused fingerprints have been identified in many different aspects of the climate system Tropospheric temperatures Tropopause height Stratospheric temperaturesSurface specific humidity Ocean temperatures Zonal-mean rainfall Near-surface temperature Sea-level pressure Water vapor over oceans Continental runoff Atmospheric temperature Thanks to Ben Santer for Content!Ben Santer

Continental warming likely shows a significant anthropogenic contribution over the past 50 years Key results of IPCC AR4: We are now able to identify human influences on climate at continental scales Thanks to Ben Santer for Content!Ben Santer

Today Observations of Ecosystems Attribution (3 ways?) –Fingerprinting –Joint Attribution (end-to-end method) Rosenzweig et al., Nature, 2008 –Event attribution

Global distribution of changes sensitive to temperature IPCC Technical Summary WG2

Summary from Rosenzweig et al., Nature, 2008Rosenzweig et al., Nature, 2008 shrinking glaciers in every continent melting permafrost shifts in the spring peak of river discharge associated with earlier snowmelt lake and river warming with effects on thermal stratification, chemistry and freshwater organisms increases in coastal erosion shifts in spring events (for example, leaf unfolding, blooming date, migration and time of reproduction), species distributions and community structure demonstrated changes in marine- ecosystem functioning and productivity, including shifts from cold-adapted to warm adapted communities, phenological changes and alterations in species interactions

Joint attribution What would you do to evaluate the theory and predictions of global warming? –Surface of planet will warm –Sea level will rise –Weather will change Think about Measurements Feedbacks Correlative behavior Impacts Joint Attribution Documented statistical analysis Process-level understanding

Joint attribution Joint Attribution –Documented statistical analysis –Process-level understanding Look to see for biological systems –Unlikely due entirely to natural variability –Consistent with estimated responses of physical or biological variables –Non consistent with alternative, plausible explanations That are in regions where physical variables, esp. temperature, can also be attributed to climate change Consist with behavior of models run with and without carbon dioxide increase

Rosenzweig et al., Nature, 2008

Today Observations of Ecosystems Attribution (3 ways?) –Fingerprinting –Joint Attribution (end-to-end method) –Event attribution

Event Attribution Barriopedro et al., Russian Heat Wave, Science, 2011Barriopedro et al., Russian Heat Wave, Science, 2011 Dole et al., Russian Heat Wave, GRL, 2011Dole et al., Russian Heat Wave, GRL, 2011 Rahmstorf, Increase of Extreme Events, PNAS, 2011Rahmstorf, Increase of Extreme Events, PNAS, 2011 Shearer and Rood, Earthzine, 2011