Global Surface Temperature Change

Abstract

1] We update the Goddard Institute for Space Studies (GISS) analysis of global surface temperature change, compare alternative analyses, and address questions about perception and reality of global warming. Satellite-observed night lights are used to identify measurement stations located in extreme darkness and adjust temperature trends of urban and periurban stations for nonclimatic factors, verifying that urban effects on analyzed global change are small. Because the GISS analysis combines available sea surface temperature records with meteorological station measurements, we test alternative choices for the ocean data, showing that global temperature change is sensitive to estimated temperature change in polar regions where observations are limited. We use simple 12 month (and n × 12) running means to improve the information content in our temperature graphs. Contrary to a popular misconception, the rate of warming has not declined. Global temperature is rising as fast in the past decade as in the prior 2 decades, despite year-to-year fluctuations associated with the El Niño-La Niña cycle of tropical ocean temperature. Record high global 12 month running mean temperature for the period with instrumental data was reached in 2010.

Evaluation of Seven Different Atmospheric Reanalysis Products in the Arctic*

“…The trends are strongly positive in all of the models in regions where the sea ice has diminished most, north of Asia and Alaska, but other regions also show positive trends. The annual trends from the reanalysis models are generally lower in the Arctic than those computed by the Goddard Institute for Space Studies (GISS) Surface Temperature Analysis (GISTEMP) dataset (Hansen et al 2010). Figure 10 shows the annual-mean 2-m air temperature trend from GISTEMP 250-km smoothing radius product over the same 1980-2009 period used in this study.…”

Observations of Local Positive Low Cloud Feedback Patterns and Their Role in Internal Variability and Climate Sensitivity

“…In the instrumental record, the global mean warming rate, $\frac{\mathrm{normal\Delta }T}{\mathrm{normal\Delta }t}$, is not constant and undergoes periods of acceleration and deceleration (Figure 1a; Hansen et al, 2010; Morice et al, 2012). The warming rate is also spatially heterogeneous with characteristic large‐scale patterns (Figures 1b and 1c).…”

The reliability of global and hemispheric surface temperature records

“…BEST is only available for the global average. The BEST series Hemispheric and global averages, based on land and marine data, from the four datasets discussed in this paper: HadCRUT4 ; NCEI/NOAA (Karl et al, 2015); GISS (Hansen et al, 2010); and Berkeley Earth (http://berkeleyearth.lbl.gov/auto/Global/Land and Ocean summary.txt).…”

“…The four main groups are: the UK Meteorological Office Hadley Centre/Climatic Research Unit, which produces HadCRUT4 ; http://www.cru.uea. ac.uk/cru/data/temperature/, and http://hadobs.metoffice.com/ hadcrut4/)-an updated version of HadCRUT3 (Brohan et al, 2006); the US National Centers for Environmental Information (NCEI; Karl et al, 2015; https://www.ncdc.noaa.gov/ climate-monitoring), which is an updated version of Smith et al (2008) and Vose et al (2012); the Goddard Institute for Space Studies (GISS; Hansen et al, 2010; http://data.giss. nasa.gov/gistemp/), which is an updated version of Hansen et al (1999Hansen et al ( , 2006; and the Berkeley Earth Group (BEST; Rohde et al, 2013aRohde et al, , 2013b; http://berkeleyearth.org/).…”