Part 4 Temperature Rise

Global Average Temperature Change for the Past 11,300 Years (Holocene) (Science, 8 March 2013: Vol. 339 no. 6124, pp )

Temperature Anomaly ( ) Baseline: Aerosols (tiny particles) Aerosols

Temperature Anomaly ( ) Baseline:

Systematic Decadal Shift to Higher Temperatures Relative to

Temperature Anomalies from 1884 to 2011 Baseline =

Arctic Air Temperature Anomalies from Proxies (blue) and Observations (red)

Record High Temperatures in the U.S. are Increasing and Record Lows are Decreasing

Lead and lag.Carbon dioxide concentrations and averages of temperature proxy records for last deglaciation, as compiled by Parrenin et al. E J Brook, Science, 2013;339: Published by AAAS

Atmospheric CO 2 and Global Warming Stabilization CO 2 Concentration: Best Estimate (ppm) Lower End (ppm) Upper End (ppm) Equilibrium Global Average Warming (°C)

Earth’s Heat Gain During the Past 50 years (10 21 Joules*) Oceans (0-2 km depth) = 245 (91%) Continents = 10.4 (4%) Earth’s Ice = 8.1 (3%) Atmosphere = 6.6 (2%) *A joule is a unit of heat energy

O CEAN H EAT C ONTENT C OMPARED TO T OTAL L AND, A TMOSPHERE AND I CE H EAT C ONTENT.

What Global Average Temperatures Become Critical and Catastrophic for Humans? T HE CURRENT BEST ESTIMATE IS 2° C (3.6° F) ABOVE PRE - INDUSTRIAL LEVELS IS CRITICAL. A BOUT 4° C (7° F) IS CATASTROPHIC. T HE E ARTH IS NOW 0.8° C (1.4° F) ABOVE PRE - INDUSTRIAL LEVELS. W HEN THE CO 2 ABUNDANCE REACHES ~430 PPM THE TEMPERATURE ANOMALY WILL EVENTUALLY REACH 2° C. A T ~670 PPM IT WILL EVENTUALLY REACH A ~4° C. T HE CURRENT ABUNDANCE (2013) IS 396 PPM AND RISING AT A RATE OF 2 PPM / YEAR, AND THIS RATE IS INCREASING. A T THE PRESENT ABUNDANCE THE TEMPERATURE WILL EVENTUALLY REACH 1.8° C. E VEN AT TODAY ’ S ABUNDANCE THE TEMPERATURE ANOMALY COULD REACH THE CRITICAL LEVEL BY THE END OF THE CENTURY. (A RMOUR AND R OE, GRL, 38, 2011; A RORA, ET AL., GRL, 38, 2011)

Probable Temperature Increases for “Low, Moderate and High CO 2 Growth” (numerical data 2011) Increase in Global Average Temperatures 2° C (3.6° F) Critical 3° C (5.4° F) 5.5° C (10° F) Catastrophic

WHAT IS CRITICAL AND WHAT IS CATASTROPHIC? CRITICAL --- serious drop in food production, serious water shortages, significant sea level rise (~1 m [3 ft]), political unrest, major drop in world economy, major animal extinctions and millions of human deaths. Third-world countries, e.g. Africa, are affected most, including large human migrations. CATASTROPHIC --- mass extinction event (>50% species extinction), major sea level rise, mass starvation, political and economic chaos, ~50% human deaths (>3 billion people). Probably the end of civilization as we know it today.