From the “Tales of the Adjustocene” department.
Guest essay by Albert Parker
A recent paper Trajectories of the Earth System in the Anthropocene (Ref.  below) claims that even if the CO2 emission reductions called for in the Paris Agreement are met, our Earth may still enter what they call “Hothouse Earth” conditions, a long-term stabilization at temperature 4-5 °C-higher than pre-industrial temperatures, and sea-level 10-60 m-higher than today. They conclude calling for an accelerated transition towards a CO2 emission-free-world-economy. There is, however, very little evidence that the apocalyptic prediction is scientific grounded. Where really measured, the temperatures haven’t increased dramatically, and similarly, the sea-levels haven’t risen dramatically. More importantly, any acceleration of the temperature warming, or any acceleration of the rate of rise of the sea-level, are hard to detect.
Before deliberating administrative adjustments, and without other man-made biases such as UHI, changes of thermometer location, air conditioners or a car park too close to thermometer location, the measured temperatures at the start of the 1900s were scarcely lower than today’s temperatures, see Figures 1 and 2 for two examples of the many.
Figure 1 –sample long-term-trend thermometer results (Alice Spring, NT, Australia). The temperatures were recorded in the Post Office / City and Airport locations. Data downloaded from www.bom.gov.au/climate/data/.
Figure 2 –sample long-term-trend thermometer results (Alice Spring, NT, Australia). The temperatures were recorded in the Post Office / City and Airport locations. Data downloaded from www.bom.gov.au/climate/data/.
Figures 3 to 6 then present the latest GHCN narrative after November 2011, and the prior narrative up to November 2011. A single round of administrative adjustments may change no-warming to warming.
Figure 3 – Latest GHCN v3 Adjusted and homogenized for Darwin. Image reproduced modified after data.giss.nasa.gov.
Figure 4 – Latest GHCN v3 Adjusted and homogenized for Alice Spring. Image reproduced modified after data.giss.nasa.gov.
Figure 5 – Prior GHCN v2 raw data for Alice Spring as per November 2011. Image reproduced modified after data.giss.nasa.gov. As the temperatures of the past should not change to fit a narrative from one day to the other, it does not seem that, based on flawed data, the latest GISSTEMP global temperature reconstruction has value.
Figure 6 – Prior GHCN v2 raw data for Darwin as per November 2011. Image reproduced modified after data.giss.nasa.gov. As the temperatures of the past should not change to fit a narrative from one day to the other, it does not seem that, based on flawed data, the latest GISSTEMP global temperature reconstruction has value.
Regarding global temperatures, apart from subjective reconstructions, where global temperatures are not the sum of the real local parts, there is also the long term trend (LTT) inferred from satellite since 1979. This close-to-a-real measurement product, shows a warming but not an acceleration, Figure 7. The slope is larger than the average of bias-free long, term-trend temperature records, also because of the much shorter record, but the differences between linear and parabolic fittings are hard to detect. Over the 30 years of observation, across the globe, the temperature is warming more on land than on ocean, and the warming is reducing moving southwards. It is maximum about the North-Pole, and it is minimum about the South-Pole. The warming of 1 °C over 1 century and the present warming rate of 1.7 °C/century because of the CO2 emission is a speculation based on adjusted data.
Figure 7 – Lower troposphere temperature results. Data downloaded from www.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt. The latest global 30 years warming rate is 1.25 °C/century, without any acceleration. It is not uniform, as it is maximum at the north pole, 60N-90N, 2.2 °C/century, and minimum at the south pole, 90S-60S, 0.8 °C/century.
Things are even worse for sea-levels. Apart from composite tide gauge records suffering of datum-shift or changes of tide gauge location, the measured sea-levels have been rising or falling mostly following the sinking or the uplift of the land since the start of the 1900s, with an about constant thermosteric component. The satellite inferred absolute GMSL, presently rising for the thermosteric effect at a rate of 3.4 mm/yr., is a speculation based on an engineered product that does not match any measure of relative sea-level rise and absolute subsidence at the tide gauges. Figures 8 to 11 are two examples of the many. Man-made and natural subsidence is responsible for sea-level rise and acceleration. This sea-level pattern is compatible with a gentle recovery from the last LIA. The claim of sea-level rising of 60-cm-by-2050 or up-to 2-meters-by-2100 because of the CO2 emission lack of any reflection in real data.
Figure 8 – sample long-term-trend tide gauge result (Fremantle, WA, Australia). In Fremantle the slope is 1.694 ±0.246 mm/yr. and the acceleration is 0.00571 ±0.01567 mm/yr². Image reproduced modified after www.sealevel.info.
Figure 9 – sample long-term-trend tide gauge result (Honolulu, HI, USA). In Honolulu the slope is +1.482 ±0.212 mm/yr. and the acceleration is -0.00539±0.01450 mm/yr². Image reproduced modified after www.sealevel.info.
Figure 10 – likely subsidence in the sample long-term-trend tide gauge location of Fremantle (PERT from GPS). The slope is -1.933±0.603 mm/yr² in PERT. Image reproduced modified after geodesy.unr.edu.
Figure 11 – likely subsidence in the sample long-term-trend tide gauge location of Honolulu (HNLC from GPS). The slope is -0.704±0.806 mm/yr. in HNLC. Image reproduced modified after geodesy.unr.edu.
The trajectories described by  are valid for the virtual-world. It is something we should not be worried about in the real-world.
 Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, Carl Folke, Diana Liverman, Colin P. Summerhayes, Anthony D. Barnosky, Sarah E. Cornell, Michel Crucifix, Jonathan F. Donges, Ingo Fetzer, Steven J. Lade, Marten Scheffer, Ricarda Winkelmann, and Hans Joachim Schellnhuber, 2018, Trajectories of the Earth System in the Anthropocene, PNAS 115 (33):8252-8259. doi.org/10.1073/pnas.1810141115