GLOBAL WARMING: COULD SATELLITE ESTIMATIONS REPLACE AIR TEMPERATURE MEASUREMENTS ?

Abstract:

The Intergovernmental Panel on Climate Change regular scientific assessments of global warming is based on measurements of air temperature from weather stations, buoys or ships. More specifically, air temperature annual means are estimated from their integration into climate models, with some areas (Africa, Antarctica, seas) being clearly underrepresented. Present satellites allow for a full coverage of our planet with a sub-daily revisit frequency and kilometric resolution, while surface temperature algorithms are now mature enough for a full quantification of our planet temperature. How do both approaches compare? We show here that satellites represent a credible alternative to air temperature measurements, with remotely sensed global temperatures from MODIS Terra and Aqua instruments in good agreement with global annual air temperatures estimated from NOAA National Climatic Data Center. Latitudinally averaged and pixel-based surface temperature trends also reproduce widely accepted air temperature patterns. Our results, through a completely independent methodology, corroborate the temperature anomalies retrieved from climate models and show maintaining the current trend, the surface temperature of our Planet would reach in the year 2040 a warming of 1.5 degrees above pre-industrial levels.