“Let’s get small” – comedian Steve Martin in the 1970’s.
https://www.youtube.com/watch?v=GOrdzCHnpw4
OK, let’s get really small to perform a reality check on the claims of detection and attribution of a human contribution to a reported trend of about 0.15C per decade.
0.15C per decade is 0.015C per year, or 0.000041C per day.
In comparison, the uncertainty in the accepted value of TSI (total solar irradiance), as a geometric average over the whole surface of the planet, is +/- 0.13 W/m^2. [1] This uncertainty arises from instrument limitations. So using a modest no-feedback response of 0.2C/(W/m^2), we do not know what the surface temperature “should” be, any closer than 0.2C * +/- 0.13W/m^2 = +/- 0.026C, to stay in “balance” with incoming sunshine by emitting IR back to space.
That single ever-present source of uncertainty, at +/- 0.026C, which seems small already, is over 600 times larger than the long-term trend being investigated. That trend is stated here on a per-day basis (0.000041C per day) to align with one cycle of solar input over the full extent of the surface. This one factor demonstrates the issue of unrealistic attribution – aside from the variation of TSI itself, aside from the time-stepping of the general circulation models, aside from radiative transfer theory, aside from the confirmed IR absorption and emission properties of CO2, aside from the effects of clouds, aside from ocean heat uptake, aside from orbital variations, aside from any other consideration.
But THEY ARE STILL TELLING US that human emissions of CO2, CH4, N2O are very likely the major cause of that 0.000041C per day long-term trend.
No. Not buying it. Reality check failed.
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[1] Loeb, et al, 2018 https://journals.ametsoc.org/view/journals/clim/31/2/jcli-d-17-0208.1.xml
“Given that the absolute uncertainty in solar irradiance alone is 0.13 W m−2 …”