If I understand the information from this link correctly,

Instrumental temperature record

between 1950 to 1980 there were negative temperature anomalies in the years of those decades.

decade difference (°C) difference (°F)
1950–1959 −0.02 -0.0360
1960–1969 −0.014 −0.0252
1970–1979 −0.001 −0.0018

This seems odd considering massive oil consumption started in 1880 IIRC, and by 1980 over 350 billions of oil barrels were already consumed (much more probably, since the data before 1950 isn't considered because there weren't reliable records).

Why was there a negative temperature anomaly between 1950 to 1980?

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    $\begingroup$ I can only see a temperature top under ww2. Also, accumulation of energy in sea affect global warming and so do long time changes in ocean currents. $\endgroup$ – Lehs Dec 23 '19 at 12:53

This phenomenon is known as global dimming.

It was due to the particles and aerosols mostly released by combustion of fossil fuels such as diesel. Those particles block the radiation from the sun, so they have a cooling effect. For some decades this effect counterbalanced the warming effect of greenhouse gases, although it is no longer the case at a global scale (see for instance Wild et al. 2007). Particles emission has been reduced thanks to better engines and new regulations, which stopped their masking effect on global warming. Which is a good thing since those particles have a serious impact on health.

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    $\begingroup$ Highly related: skepticalscience.com/global-cooling-mid-20th-century-basic.htm . $\endgroup$ – David Hammen Dec 23 '19 at 11:51
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    $\begingroup$ Just a gut feeling, but i suggest to be careful with that site ... always doublecheck. Where does it cite it's deductions ? $\endgroup$ – user18411 Dec 23 '19 at 12:31
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    $\begingroup$ The effect of particles on health (lungs mostly) is well known, that's why we took those regulations in the first place. But I guess you mean if we did some kind of geoengineering by spreading particles in the atmosphere? I don't know. I think it might work to cool the planet for a while, but the particles would eventually sediment back to the ground, where they would be harmful to people. And you'd have to spread more and more of them to keep the effect going... $\endgroup$ – Jean-Marie Prival Dec 23 '19 at 14:42
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    $\begingroup$ At least - definitive proof that environmentalists are actually causing global warming. (I jest, but some will see it that way) $\endgroup$ – user253751 Dec 23 '19 at 15:00
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    $\begingroup$ @ebv Yes, it's fighting the consequences of global warming instead of tackling the source of the problem... $\endgroup$ – Jean-Marie Prival Dec 23 '19 at 15:14

Independently from dimming by aerosols, a change in the North Atlantic circulation pattern seemed to have played a role. This might be connected to the multidecadal variability in sea surface temperature.


Newer work assumes that the role of aerosols may have been overestimated as a driver for the multidecadal variability. But then again, there may be regional differences of the effect of such forcing.

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    $\begingroup$ Interesting, thanks for sharing this! $\endgroup$ – Jean-Marie Prival Dec 23 '19 at 14:43
  • $\begingroup$ You've probably realized that I love to debate :-) $\endgroup$ – user18411 Dec 23 '19 at 14:56

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