Had science in 1860 already been very advanced, we would have discovered anthropogenic climate change back in 1885. Really!

More junk science related to the Global Warming hoax and Climate Change religion!

This "research" too is totally tainted by a severe bias! Humans are bad for climate nonsense! Key ideological term/label here again: anthropogenic. Sounds very sophisticated, but it is more indicative of a superstition than science.

It is truly astonishing that the prestigious PNAS (Proceedings of the National Academy of Sciences) accepted such junk for publication!

If our current climate science still was not so immature and more like a superstition than a science, we would perhaps admit we still know very little about the very complex natural phenomenon of climate.

One of many serious challenges to this "thought experiment": Why did the Medieval Warm Period (900 CE to 1300 CE) follow the Late Antique Little Ice Age (536 CE to around 660 CE).

What happens when the earth comes out of an ice age? A warming period! When did the last ice age (The Little Ice Age) end? about 1850.

In 1860, nobody would have predicted the enormous global human population growth since the 1950s. 

Today's climate models are largely junk!

"Climate Change/We could have known

...

At what point in the past could we have detected the anthropogenic influence [???] on climate that now is so glaringly evident had we had good enough instrumentation?

Santer et al. conducted the thought experiment by assuming that the necessary tools to monitor global-scale atmospheric temperatures were available as far back as 1860, and then looked at the fingerprints of atmospheric temperature changes that would have been observed.

They found that a clear fingerprint of human activity, driven by atmospheric carbon dioxide, would have been apparent in stratospheric cooling by 1885. Thus, our impact on climate would have been observable even before the advent of gas-powered automobiles."

From the significance and abstract:

"Significance

When could scientists have first known that fossil fuel burning was significantly altering global climate? We attempt to answer this question by performing a thought experiment with model simulations of historical climate change. We assume that the capability to monitor global-scale changes in atmospheric temperature existed as early as 1860 and that the instruments available in this hypothetical world had the same accuracy as today’s satellite-borne microwave radiometers.

We then apply a pattern-based “fingerprint” method to disentangle human and natural effects on climate. A human-caused stratospheric cooling signal would have been identifiable by approximately 1885, before the advent of gas-powered cars. Our results suggest that a discernible human influence on atmospheric temperature has likely existed for over 130 y.

Abstract

The physics of the heat-trapping properties of CO2 were established in the mid-19th century, as fossil fuel burning rapidly increased atmospheric CO2 levels.

To date, however, research has not probed when climate change could have been detected if scientists in the 19th century had the current models and observing network.

We consider this question in a thought experiment with state-of-the-art climate models [???]. We assume that the capability to make accurate measurements of atmospheric temperature changes existed in 1860, and then apply a standard “fingerprint” method to determine the time at which a human-caused climate change signal was first detectable.

Pronounced cooling of the mid- to upper stratosphere, mainly driven by anthropogenic increases in carbon dioxide, would have been identifiable with high confidence by approximately 1885, before the advent of gas-powered cars. These results arise from the favorable signal-to-noise characteristics of the mid- to upper stratosphere, where the signal of human-caused cooling is large and the pattern of this cooling differs markedly from patterns of intrinsic variability.

Even if our monitoring capability in 1860 had not been global, and high-quality stratospheric temperature measurements existed for Northern Hemisphere mid-latitudes only, it still would have been feasible to detect human-caused stratospheric cooling by 1894, only 34 y after the assumed start of climate monitoring. Our study provides strong evidence that a discernible human influence on atmospheric temperature has likely existed for over 130 y."

In Other Journals | Science

Human influence on climate detectable in the late 19th century (open access)