October Global Temperature Update
Hansen & Sako, Columbia University (Nov. 18, 2021):
"October global temperature was close to an October record for the 1880-2021 period of near-global instrumental data, despite the cooling effect of a fairly strong, double-dip La Nina. The October global temperature – the 4th warmest October in the period 1880-present – was +1.23°C relative to 1880-1920."
"Almost all ENSO (El Nino Southern Oscillation) models including NOAA’s NCEP model project minimum Nino3.4 temperature by December. Given the present extreme planetary energy imbalance – more solar energy absorbed than heat radiated to space – the 12-month running-mean global temperature is now at or near its minimum, which means that the annual 2021 temperature will be the sixth warmest year (the five warmest being 2020, 2016, 2019, 2017, 2015)."
- Columbia U Global average temperature emails (pdf version) 2015 - present
- Columbia U A better graph (Hansen & Sato, 2016)
*Note: NOAA-NCEI reports temperature increases relative to the 20th Century global average surface temperature, not pre-industrial levels.
Dec. 2020: Columbia University Reports Observed Acceleration in Global Warming:
"Abstratct: Record global temperature in 2020, despite a strong La Niña in recent months, reaffirms a global warming acceleration that is too large to be unforced noise – it implies an increased growth rate of the total global climate forcing and Earth’s energy imbalance. Growth of measured forcings (greenhouse gases plus solar irradiance) decreased during the period of increased warming, implying that atmospheric aerosols probably decreased in the past decade. There is a need for accurate aerosol measurements and improved monitoring of Earth’s energy imbalance.
November 2020 was the warmest November in the period of instrumental data, thus jumping 2020 ahead of 2016 in the 11-month averages. December 2016 was relatively cool, so it is clear that 2020 will slightly edge 2016 for the warmest year, at least in the GISTEMP analysis. The rate of global warming accelerated in the past 6-7 years (Fig. 2). The deviation of the 5-year (60 month) running mean from the linear warming rate is large and persistent; it implies an increase in the net climate forcing and Earth’s energy imbalance, which drive global warming."
Fig. 2. Global temperature and Niño3.4 Index through November 2020.
"The science is sobering—the global temperature in 2012 was among the hottest since records began in 1880. Make no mistake: without concerted action, the very future of our planet is in peril."
NOAA annual global analysis for 2020:
"With a slightly cooler end to the year, the year 2020 secured the rank of second warmest year in the 141-year record, with a global land and ocean surface temperature departure from average of +0.98°C (+1.76°F). This value is only 0.02°C (0.04°F) shy of tying the record high value of +1.00°C (+1.80°F) set in 2016 and only 0.03°C (0.05°F) above the now third warmest year on record set in 2019. The seven warmest years in the 1880–2020 record have all occurred since 2014, while the 10 warmest years have occurred since 2005. The year 1998 is no longer among the 10 warmest years on record, currently ranking as the 11th warmest year in the 141-year record. The year 2020 marks the 44th consecutive year (since 1977) with global land and ocean temperatures, at least nominally, above the 20th century average.
The decadal global land and ocean surface average temperature anomaly for 2011–2020 was the warmest decade on record for the globe, with a surface global temperature of +0.82°C (+1.48°F) above the 20th century average. This surpassed the previous decadal record (2001–2010) value of +0.62°C (+1.12°F).
The global annual temperature has increased at an average rate of 0.08°C (0.14°F) per decade since 1880 and over twice that rate (+0.18°C / +0.32°F) since 1981.
The 2020 Northern Hemisphere land and ocean surface temperature was the highest in the 141-year record at +1.28°C (+2.30°F) above average. This was 0.06°C (0.11°F) higher than the previous record set in 2016. Meanwhile, the annual Southern Hemisphere land and ocean surface temperature was the fifth highest on record."
[NOAA/NCEI global analysis for 2020 accessed February 21, 2021].
"Globally-averaged temperatures in 2015 shattered the previous mark set in 2014 by 0.23 degrees Fahrenheit (0.13 Celsius). Only once before, in 1998, has the new record been greater than the old record by this much."
~ NASA Goddard Institute for Space Studies [NASA post of January 20, 2016]
Before the end of 2015, scientists projected that average global temperature increase for 2015 will exceed 1°C above pre-industrial levels. The years 1850-1900 are used as the pre-industrial baseline by the MET Office and Climate Research Unit at the University of East Anglia in the UK. The MET Office released this statement in November 2015:
"This year marks an important first but that doesn't necessarily mean every year from now on will be a degree or more above pre-industrial levels, as natural variability will still play a role in determining the temperature in any given year. As the world continues to warm in the coming decades, however, we will see more and more years passing the 1 degree marker - eventually it will become the norm."
~ Peter Stott
Head of Climate Monitoring and Attribution (MET Office)
MET Office '15 Global temperatures to reach 1°C for first time
MET Office 2015 global temperature forecast
NSIDC '15 Record warmth in Antarctica
CO2.Earth Projections for Year 2100
CO2.EarthTemperature guardrail targets
Climate Central Rising global temperatures and CO2
Columbia U Global Temperature
The Royal Society Four degrees and beyond
Year-to-Date Global Temperature
NOAA compares 2015 monthly anomolies (compared to 20th Century average temperature) with 2014, 2010, 2013, 2005, 2009 and 1998. In rank order, these are the six warmest years since 1880.
Global Temperature Data Sets
Global Temperature Data
Prominent Global Surface Temperature Data Sets
(montlhy & annual)
1880-Present (csv, xml, json)
(monthly & annual)
Ten Global Temperature Records That Tell The Same Story
About Anomolies & Absolute Temperatures
NOAA-NCEI Absolute temperatures versus anomolies [FAQ 1, 2, 7 & 8]
SkS Anomolies, baselines, 2°C limit [Honeycutt | The 1°C milestone]
NOAA-NCEI Monthly global land & ocean surface mean temperature anomolies: 1901-2000 [.dat]
NOAA-NCEI Annual global land & ocean surface mean temperature anomolies: 1901-2000 [.dat]
W/M2 (Earth's Energy Imbalance)
"The inferred planetary energy imbalance, 0.58±0.15 W/m2 during the 6-yr period 2005-2010, confirms the dominant role of the human-made greenhouse effect in driving global climate change."
~ Hansen et al. (2011)
Measurements of changes in average global temperature at the earth's surface tell just part of the global warming story. A measure of earth's energy imbalance gives us a more holistic indicator that includes, for example, heat absorbed by the ocean. Energy imbalances are measured in watts per square meter (W/m2), not degrees Celsius.
At present, almost 4,000 Argo floats measure temperature and salinity of the top 2 kilometres of the world's oceans. This allows the best assessment so far for earth's energy imbalance. Hansen et al. (2011) discuss the need for further improvements in observations, measurements and research to achieve more precise energy balance data.
The remaining text on this page is copied from a 2012 NASA GISS science briefing on Earth's Energy Imbalance.
Earth's energy imbalance is the difference between the amount of solar energy absorbed by Earth and the amount of energy the planet radiates to space as heat. If the imbalance is positive, more energy coming in than going out, we can expect Earth to become warmer in the future — but cooler if the imbalance is negative. Earth's energy imbalance is thus the single most crucial measure of the status of Earth's climate and it defines expectations for future climate change.
Climate forcings are imposed perturbations to Earth's energy balance. Natural forcings include change of the Sun's brightness and volcanic eruptions that deposit aerosols in the stratosphere, thus cooling Earth by reflecting sunlight back to space. Principal human-made climate forcings are greenhouse gases (mainly CO2), which cause warming by trapping Earth's heat radiation, and human-made aerosols, which, like volcanic aerosols, reflect sunlight and have a cooling effect.
NASA GISS '12 Science briefs: Earth's energy imbalance
Scripps UCSD Argo
Hansen, J., Sato, M., Kharecha, P., & von Schuckmann, K. (2011). Earth's energy imbalance and implications. Atmospheric Chemistry and Physics, 11(24), 13421-13449. doi:10.5194/acp-11-13421-2011 [AC&P + .pdf]
Ocean Heat Content
Global warming means the earth is retaining excess heat. About 93% of the total excess is found in the ocean. Over the past 50 years, the upper ocean (0 to 700 metres) accounted for about 64% of the total.
"The large inertia of the oceans means that they naturally integrate over short-term variability and often provide a clearer signal of longer-term change than other components of the climate system."
~ IPCC (Rhein et al., 2013, p. 260)
Where's the heat?
IPCC '13 Observations: Ocean (AR5, WG1, CH3) [43MB]
Rhein, M., Rintoul, S. R., Aoki, S., Campos, E., Chambers, D., Feely, R. A., . . . Wang, F. (2013). Observations: Ocean. In T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, B. V., & P. M. Midgley (Eds.), Climate change 2013: The physical science basis. Contribution of working group I to the fifth assessment report of the Intergovernmental Panel on Climate Change (pp. 255-315). Cambridge, UK and New York, USA: Cambridge University Press.