SOLAR CYCLE SPURS GREENHOUSE GASES - STUDIES 2 WASHINGTON GLOBAL WARMING IS CAUSED IN PART BY THE EMISSION OF GREENHOUSE GASES, INCLUDING CARBON DIOXIDE AND METHANE. THESE GASES ARE EMITTED NATURALLY BUT ARE ALSO THE RESULT OF THE BURNING OF FOSSIL FUELS, ESPECIALLY COAL AND PETROLEUM PRODUCTS. THESE GASES SWADDLE EARTH IN A LAYER THAT LETS THE SUN'S WARMTH IN BUT DOES NOT ALLOW IT TO EASILY ESCAPE. OVER THE PAST 30 YEARS, EARTH HAS WARMED BY 1.08 DEGREES FAHRENHEIT (0.6 DEGREES CELSIUS), NASA HAS REPORTED. OVER THE PAST 100 YEARS, IT HAS WARMED BY 1.44 DEGREES F (0.8 DEGREES C), INDICATING A RECENT ACCELERATION IN WARMTH. CURRENT CLIMATE MODELS PREDICT TEMPERATURE INCREASES OF 2.7 TO 8.1 DEGREES F (1.5 TO 4.5 DEGREES C), BUT TORN'S TEAM FOUND THAT ADDITIONAL CARBON DIOXIDE CAUSED BY THE NATURAL SOLAR CYCLE COULD PUSH THOSE ESTIMATES HIGHER. TAKING THIS INTO ACCOUNT COULD MEAN TEMPERATURE INCREASES OF 2.9 TO 11 DEGREES F (1.6 TO 6 DEGREES C), THE SCIENTISTS SAID. THE HIGHER TEMPERATURES ARE MORE LIKELY, THEY SAID IN A STATEMENT. THE EUROPEAN TEAM ESTIMATED THAT GLOBAL WARMING IN THE NEXT CENTURY MAY BE 15 PERCENT TO 78 PERCENT HIGHER THAN CURRENT ESTIMATES BECAUSE THESE PREDICTIONS FAIL TO TAKE INTO ACCOUNT THE FEEDBACK MECHANISM INVOLVING CARBON DIOXIDE EMISSIONS. BOTH ARTICLES ARE TO BE PUBLISHED ON FRIDAY IN GEOPHYSICAL RESEARCH LETTERS.
