Earth's Energy Imbalance
0.47± 0.1 W/(m^2) immediately below is out of date.
Earth's energy imbalance has tripled (2022) since then (2000).
See graph 3rd below for 2000-2022.
The light blue line is for ocean uptake of heat (from greenhouse gases mostly). The orange line is radiation by Earth from the top of the atmosphere. Since about 90% of incoming radiation is absorbed by the world ocean, the two lines are in good agreement. The trend lines are in even closer agreement. Note the ocean heating dip in 2016, when more of the heat gain wound up in the atmosphere. El Niño.
Earth's Energy Imbalance Removes Almost All Doubt from Human-Made Climate Change 0821 - Earth's energy imbalance approximately doubled from 2005 to 2019.
A more granular resolution and update of the figure above. The imbalance trend for 2023 is 1.50 W/(m^2), up from 1.29 above in 2022 and 1.33 farther above, over March 2020 to February 2023.
Earth Energy Imbalance Estimates, across Studies (0721) My spreadsheet below summarizes studies cited in von Schuckmann's paper. It underlies the graph above. The linear time trend is shown by orange dots. 0.87 Watts / sq meter = 450 TW (billion Watts) when summed across Earth’s surface. This 0.87 (450) rate is about 30 times the human rate of energy use now.
Heat Stored in the Earth System - Where Does the Energy Go? 0920 - Abstract. - von Schuckmann, Hansen et al. Earth gained 358 zJ over 1970-2018. This 48-year total is about 600 times annual human energy use, or 10-20 times cumulative human energy use.
Over this period, the oceans account for 89% (52% in the upper 700 meters, 28% 700-2,000 meters deep, and 9% below that); land (continental crust) 6%; melting ice 4%; and atmosphere 1%. Over the shorter and most recent 2010-2018 period, these figures were 90% ocean (52-30-8%); 5% land; 3% ice; and 2% atmosphere. The rate of heat gain was 0.87±1.2 Watts / sq meter over 2010-2018.
There have been various comparable estimates before and since, as shown in the diagram and spreadsheet above. 0.47 in the diagram below right is for 1970-2018; 0.87 is for 2010-2018. It has since risen, to 1.33 (see above) now, to about 700 TW over the entire globe, from 450 in some earlier years. In order to stabilize Earth’s surface temperature (at a level substantially higher than today’s unless all excess CO2 is removed immediately), Earth’s CO2 level must be reduced from 424 ppm to 350 ppm (about 4-5°C above 1880 level).
Heat Stored in the Earth System - Where Does the Energy Go? 0920 - PDF 29 pages, the main study. Earth's heat gain rose to 0.87 W per sq meter, from 0.47 averaged over 48 years or (0.40 over 51 or 56 years). Earth's rate of heat gain has increased over time, as has Earth’s surface temperature (about ~2% of the heat gain). Excerpted figures are below. The gray graph at the right is for global cumulative heat storage within continental landmasses since 1960 CE, a blow-up of the orange portion of the graph below at left.
ZJ = 10 years of US energy use. 1022 Joules = 100 years of US energy use.
Also from von Schuckmann, about just the ocean, (more above) is energy density (energy / area), while the graphs above are for energy summed over all the Earth’s surface.
Global Temperatures in the Thermometer Era
Sea + Land surface warming rate over the past century was ~1.2°C. Compare to rates of 0.03 to 0.06°C warming highlighted above: for the PETM spike 55 million years ago, and coming out out the 2nd most recent and most recent ice ages ~130 and ~10 thousand years ago. Current warming is 20 to 40 times as fast as the previous fastest warming episodes we can find.
The observed warming varies by latitude, as shown. In general, the rate of warming increases toward the poles and is faster in the land (northern) hemisphere that in the water hemisphere. The figure also compares war ming in data sets from NASA, the US National Oceanic and Atmospheri Administration, and the UK Meteorological Office. The set of 4 graphs below needs updating, especially the NASA-NOAA-UKMO one, in light of NASA’s decision in 2018 to stop reporting land surface temperatures.
The Way Forward
One or Two Views
CDR = Carbon Dioxide Removal
SRM = Solar Radiatoion Management
DAC = Direct Air Capture
RCP = Representative Concentration Pathway (8.5, 4.5, 3.4, and 2.6, in decreasing order of emissions)
Section Map: Heat
Misc.