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The Climate is Warming: So Expect More Blizzards… Dr. Bruce A. Wielicki NASA Langley Research Center. Earth Ambassador Education June 4, 2012. NASA Has Engaged in Earth Science From the Very Beginning. TIROS IX mosaic, February 13, 1965. Earth View From MODIS on the Terra Spacecraft 2001.
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The Climate is Warming:So Expect More Blizzards…Dr. Bruce A. WielickiNASA Langley Research Center Earth Ambassador Education June 4, 2012
NASA Has Engaged in Earth Science From the Very Beginning TIROS IX mosaic, February 13, 1965
What is Climate? • Climate is the long term average of weather. • 14-day weather prediction limit: but no known limit to climate prediction. • Weather data accuracy is 1 degree, but climate accuracy is 0.1 degree: a factor of 10 tougher measurement. • Climate is much more than weather. • ocean circulation, sea level, salinity • biosphere, greenhouse gas chemistry, • ice sheets, snow, sea-ice
Mean Temperatures 1971 - 2000 Virginia Daily Means March 2010 Virginia Monthly Means March 1971 - 2000 Global Annual Means 1971 - 2000 61.5°F 58.2°F 56.9°F 49.9°F 40.3°F 35.5°F °F °F °F
Where does March 2012 Fit? Virginia Monthly Means March 1971 - 2000 55.5F March 2012 Record Heat in Virginia (117 years) 49.9°F 40.3°F °F °F
Rules of Natural Variability • Its everywhere and occurs on all time and space scales in weather and climate • Its largest at the smallest space/time scales. • Yorktown temperature 7pm, 3/31/11 • Its smallest at the largest space/time scales. • Global average for 2000 to 2010 • Dynamics dominates shortest time/space scales. • Cold fronts, thunderstorms, hurricanes • Energetics dominates largest time/space scales • Seasons, ice ages, human carbon dioxide emissions
What about this March globally? Virginia is 5.5C or 10F warmer than normal: about "normal" for 2100
How do we put this in context of U.S.? Most of the U.S. states set all time temperature records (118 years) Entire U.S. average temperature was warmest as well (+8.6F warmer) for data see: http://lwf.ncdc.noaa.gov/special-reports/march-2012-heat-wave/page-4#state-VA
Month to Month Temperature Variability: Winter Hansen and Sato, 2011
Seasonal Temperature Variability: Summer Hansen and Sato, 2011
Global surface temperature change 1850-2005 IPCC 2007 IPCC, 2007
Human Influence on Climate Carbon Dioxide Trends: 100yr lifetime Methane Trends Sulfate Trends Global Temperature Trends From M. Prather University of California at Irvine
The Ice Ages: Temperature, Sea Level Sea Level varies by 100m (300ft) from glacial to Interglacial periods Paleo data used to estimate radiative energy climate forcing (doubled CO2 = 4 W/m2 Climate Model uses paleo forcing to predict temperature change and compares well to Paleo temperature data. Hansen, 2007
Earth System Response How does the Earth Respond? Forces Acting On the Earth System IMPACTS Feedback Of the total forcing of the climate system, 40% is due to the direct effect of greenhouse gases and aerosols, and 60% is from feedback effects, such as increasing concentrations of water vapor as temperature rises.
Major Climate System Elements Carbon Cycle Water & Energy Cycle Coupled Chaotic Nonlinear Atmosphere and Ocean Dynamics Atmospheric Chemistry
Human Radiative Forcing of Earth's Energy Balance & Climate 1750-2005 IPCC, 2007
What do physical climate models predict the change should be? Natural Forcings Cannot Explain Observations IPCC, 2007 Natural Forcings: Solar, Volcanic Eruptions Human Forcings: CO2, Methane, Aerosols, Ozone, Land change
Climate Model Predictions: Add Human Forcing Natural Forcings And Human Forcings Do Explain Observations IPCC, 2007 Natural Forcings: Solar, Volcanic Eruptions Human Forcings: CO2, Methane, Aerosols, Ozone, Land change
What do climate models predict regional change should be? IPCC, 2007
Global Temperature Predictions Uncertainty in climate sensitivity Uncertainty in future emissions IPCC, 2001
Global Temperature Predictions IPCC, 2007
What about rainfall? Can Climate Models Predict It? Winter: Dec/Jan/Feb Summer: Jun/Jul/Aug Obs Models 3 mm/day = 3.5 inches per month = typical for Virginia IPCC, 2007
What do climate models predict for Rainfall Change From Current to 2090-2099 Wet gets wetter, Dry gets drier Winter: Dec/Jan/Feb Summer: Jun/Jul/Aug IPCC, 2007 Change is given in percent of current rainfall climatology Colored regions where at least 2/3 of climate models agreed Stippled regions are where 90% of climate models agreed Color shown is the average of all climate model predictions
Precipitation Extremes IPCC, 2007
Time series of five-year mean area-averaged Precip Index anomalies over Northern Hemisphere land during 1951–99. 1-day and 5-day maximum annual regional precip ANThropogenic Forcing, ALL = Anth + Natural S-K Min et al.Nature470, 378-381 (2011) doi:10.1038/nature09763
Climate Model Sea Level Predictions Sea level rise continues for centuries: Long after atmospheric temperature stabilizes IPCC, 2001
300 ft ft 150 ft -150 ft -300 ft -450 ft “The Long Thaw” Archer, 2009
Sea Level Rise of 4 meters = 12 ft, Peninsula IPCC: 1 to 11ft ultimate sea level rise from ocean water thermal expansion, depending on 2000-2100 emissions. Much larger rise if ice sheet losses: caused 12 to 18 ft sea level rise when poles were warmer 125,000 years ago.
The 3 Laws of Climate Change Accuracy in the data and the science Accuracy in public information Accuracy in policymaking
American Association for the Advancement of Science: millions of scientists, 1848 American Geophysical Union: 50,000 members in 137 countries, 1919 American Meteorological Society: 14,000 members, 1919 All endorse the IPCC conclusions
Where is Accurate Public Information? IPCC Assessment Reports www.ipcc.ch Major scientific associations www.aaas.org, www.agu.org www.ametsoc.org U.S. Global Change Research Program www.globalchange.gov
Common Climate Myth #1 Its just natural variability like glacial periods! - glacial periods take 100,000 years: not 100 - glacial periods are forced by earths orbit around the sun: its tilt (how strong the seasons are) and the earths elliptical orbit (whether northern or southern hemisphere is closer to the sun in summer - these natural variations would take us to the next ice age in 50,000 years or so. - our CO2 fossil fuel emissions will equal the energy forcing of the glacial cycle in the < 100 years: 1,000 times faster forcing of climate than glacial cycles but of similar magnitude. Fact: we are accidentally "geo-engineering" our own planet.
Common Climate Myth #2 We can't predict weather 5 days from now! How can possibly predict climate 100 years out? - Weather is driven by dynamics: inherently chaotic - Climate is driven by energetics: more constrainted physics - YOU already know how to predict climate 6 months out better than the weatherman can predict 5 days out - How different is the Gloucester average summer daytime high than the winter daytime high? This climate difference is driven by energetics: more sun in the summer than winter. Fact: climate is inherently more predictable than weather. The longer the time average the more predictable it becomes (month, year, decade)
What are the IPCC Conclusions? • "Global atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values determined from ice cores spanning many 1000s of years" • "Warming of the climate system is unequivocal (>99% certain) and is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level." • "The last time the polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4 to 6 meters sea level rise" (I.e. 12 to 18 ft). • "Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (>90% certainty) due to the observed increase in anthropogenic greenhouse gas concentrations" • "Anthropogenic warming and sea level rise would continue for centuries due to the timescales associated with climate processes and feedbacks" IPCC Policymakers Summary: The Physical Science Basis, Feb 2007
What can we do about it? • Decide to lower your carbon footprint: U.S.: 50,000 lbs/yr/person • buy more fuel efficient cars • make your house more efficient: see energystar.gov and start by using the "energy yardstick" to gauge where you are. web site has lots of ideas. • make your energy "cost/benefit" decisions on 10 year time scales, not 1. • most in the U.S. could cut 50% of emissions and save money doing it. • stabilizing CO2 requires ~ 80% reductions in emissions • Support development of renewable energy (wind, solar, etc) and carbon storage • Support more rigorous climate science to allow more accurate predictions of future climate change: better policy decisions and less economic risk • Try to think long term and not short term.
My home energy improvements and savings: 50% nat. gas, 60% electric Payback time ~ 6 years, now saving $1800/year, tax free, $36,000 home value increase Lots of small changes, not big ones (total cost $9200)(insulation, duct sealing, air leak sealing, cellular blinds, programmable thermostat, flourescent lights, reduce vampire electricity. but no windows, heating, or ac changes! Cost, $9200 (including interest of home equity loan)