NASA - GISS Relative to 1951-1970 Dr. Patricia Yager"Dept. of Marine Sciences"UGA"http://earthobservatory.nasa.gov/Features/WorldOfChange/decadaltemp.php!THEMES AND IDEAS 1°C average global warming can mean a very hot Georgia in July Climate change; not just global warming The ocean plays a huge role in absorbing excess heat and CO2 Ecosystem impact is global; the canary is dead… Winners and losers; does community structure matter? The ocean is helping us out, but future is uncertain. B. Heimlichhttp://www.giss.nasa.gov/research/news/20110113/ The world is ~ 2°F warmer than it used to be Climate Change Relative to 1950-1979 mean 1°C ~ 2°F!Muller et al. 2011 Temperature trend confirmed even by skeptic: http://berkeleyearth.orgNASA - GISS Global average is sum of regional variation… Relative to 1951-1970 • Oceans versus land • Regionality -4 -2 0 +2 +4 °F!…which is the average of the monthly anomalies -7 -4 0 +4 +7 °F!Note that scale has doubled!On a given day, at a given place, the anomaly can be huge: 108°F – 90°F = 18°F 42.2°C – 32.2°C = 10°C …which is the average of all the daily anomaliesThe effect on temperatures when (a) the mean temperature increases (b) the variance increases (c) when both the mean and variance increase IPCC$2001$h"p://www.ncdc.noaa.gov/extremes/cei/graph/1/01812:Decadal climate variabilityhttp://www.globalchange.gov/ Other:extremes:also:changing:http://www.globalchange.gov/Why is this happening?John Tyndall 1850 – Greenhouse gases Sven Arrhenius 1889 – Radiative forcing Roger Revelle (1909-1991) Oceanographer – CO2 in seawater Anthropogenic warming G.S. Callendar 1930-50‘s Mechanisms of human-driven climate change have been known for more than 160 years 1979 NAS Hans Suess - 1970’s Fossil carbon isotopes Calculated ~ 8°F warming under doubled-CO2 scenario Ronald Reagan - 1980’s Signed Montreal Protocol, argued for good stewardship and energy independence through non-fossil energyEnergy: • Absorption • Reflection • Transmission Depends on: • Atm Gases • Particles • Clouds • Wavelength Recall the earth’s heat budgetFrom Houghton 2004 Greenhouse gases trap the heat in the atmosphere and air temperature must rise to balance outgoing and incoming radiation. 59°F 59°F 59+2.2°F 59+4.5°FThe Mauna Loa Observatory in Hawaii has been measuring gases in the air since 1958 http://scrippsco2.ucsd.edu/ We:have:increased:by:~50%:the:concentraCon:of:CO2:in:the:atmosphere:since:the:start:of:the:industrial:revoluCon::(280:ppm):GLOBAL CO2 EMISSIONS!8000 MMT per year!=8 GT / y!Per capita CO2 emissions = 1.2 MT!http://cdiac.esd.ornl.gov/ 1 metric ton = MT = 106 g = 2205 lbsUS & Canada 1750 MMT per year Per capita CO2 emissions = 5.5 MT!http://cdiac.esd.ornl.gov/ 1 metric ton = MT = 106 g = 2205 lbsCH2O + 1.5O2 → CO2 + H2O 8 29 26 11 pounds pounds pounds pounds CO2 Production by Automobiles CH2O O2 CO2 + H2O 1 gal of gas weighs approximately 8 pounds If you drive 10,000 miles per year at 20 mpg, that’s 5.9 metric tonnes of CO2 Courtesy of Richard Jahnke 1 metric ton = MT = 106 g = 2205 lbsElectricity from coal: 2 pounds CO2 per kilowatt hour Electricity from gas: 1.1 pounds CO2 per kilowatt hourIt’s not just CO2Solar cycle does influence global climate – but it explains <10% of the observed warmingNational Academies - America's Climate Choices http://dels.nas.edu/Report/Americas-Climate-Choices/12781 Climate model projections!Hadley Centre Model projection 2 4 6 8 10 12 14 16 °F:National Academies - America's Climate Choices http://dels.nas.edu/Report/Americas-Climate-Choices/12781 Number of >100°F days in Georgia rises to more than 60But the HEAT BUDGET is more than just temperature changes Heat = a measure of the total kinetic energy in a substance (units = calories) Temperature = a property of a substance that depends on the average amount of kinetic energy per unit mass (units = degrees: °F, °C, K)NASA - GISS Where is the heat? Relative to 1951-1970 -4 -2 0 +2 +4 °F!Where is the heat?Ocean warming dominates the global energy storage inventory. Warming of the ocean accounts for about 93% of the increase in Earth's energy inventory between 1971 and 2010 with warming of the upper (0–700 m) ocean accounting for about 64%of the total.Heat Capacity = the amount of heat required to cause a change in the temperature of a substance 1 degree C. Pure water has the highest heat capacity of all common solids and liquids (1 calorie per 1 gram per 1°C)Because of water’s high heat capacity, moving water around moves a large amount of heatIPCC 2013 Ocean heat uptake pathwaysIt is virtually certain (99-100% probability) that the upper ocean (above 700 m) has warmed from 1971 to 2010. IPCC 2013 Depth-averaged 0–700 m temperature trend for 1971–2010 Globally-averaged temperature anomaly (time versus depth, colors and grey contours in °C) relative to the 1971–2010 mean.Sea level rise for 1961-2008 (Church et al. (2011) 100 mm ~ 4 inches Warming of the sea water accounts for about half of the observed rise in sea levelSallenger Et Al 2012 Because the warming has not been equal everywhere, the sea level rise has not been equal everywhere eitherThe melting of ice also absorbs some heatIt costs energy to go from solid to liquid or liquid to gas evaporation cools skin - ice chills your tea Heat is released when go from gas to liquid or liquid to solid warm vapor condenses when cooled (fog, frost)can occur at any temperature as long as there is enough kinetic energy. At 100°C, 540 cal/g are required. At 20°C, 586 cal/g are required. 1. Evaporation tends to cool off the molecules left behind 2. Heat energy goes along with vapor molecules.IPCC 2013 Latent heat of vaporization: an intensification of the hydrologic cycle: Sea Surface Salinity Evaporation - Precipitation Average Change (2008 – 1950) Salty areas getting saltier Fresher areas getting fresherMelting absorbs heat without changing temperature Pritchard et al. 2009 Surface height change (2003-2008) The PIG, Smith, and Thwaites Glaciers are thinning at a rate of nine meters per year. Reduced glacier ice extent and thicknessPeople in Netherlands care a lot about this issue. They have