Even though the world has been warming since the 1800s, when would you say climate change became noticeable? My guess would be the 1980s when people started talking about it, and in a major way probably when the El Nino of 1998 hit and especially after the year 2000.
I’ve heard that the Yellowstone fires of 1988 was one of the first major global warming influenced disasters.
Noticeable in that scientists were discussing it, or that the average person was discussing it? There’s probably a 10-20 year gap between those two, at least.
I read a multi-page article in Scientific American in 1986 describing the measured global warming up to that point and correlating it with CO2 increases. The worry was that the error bars of the measured temperature increases were rather wide. Also there were some questions about unreliable weather stations, heat island effects, etc. Of course, thirty years later we have tons more data, the curve has continued upward, and the error bars are smaller, compared to the size of the increase.
Apart from thermometer readings at weather stations, the first time I heard about studies showing things like displaced migration routes and retreating glaciers were in the early 1990s.
Here is a timeline of milestones in climate science from the American Institute of Physics. I’ve highlighted some that are pertinent to your question from the scientist and public perspectives.
The charlatans who were pushing the next ice age in the 1970s realized in the late 1980s and like the Ministry of Truth in “1984”, they immediately switched to saying Oceania has always been at war with Eastasia so they could impose their ideological fascism and get rich too.
FYI - The world has been warming since the last ice age.
Sounds legit.
Moderator Warning
Jim’s Son, you’ve been warned for political jabs before, so you know this is out of line. This is an official warning.
Colibri
General Questions Moderator
Moderating
This is in no way responsive to the OP. Let’s keep irrelevant remarks out of this.
Colibri
General Questions Moderator
**[Instructions to All]
I don’t want to see this become yet another debate on global warming. For the purposes of this thread, let’s assume that the IPCC and the vast majority of climate scientists are correct with regard to anthropogenic climate change. The question at hand in this thread is when global climate change was first identified by scientists, and when it became generally known to the public.
Those who wish to debate whether or not this is occurring can start yet another thread in Great Debates, if you must.
Colibri
General Questions Moderator**
I’ll take a crack at it. The question can be interpreted to mean when the majority of scientists recognized the human factors in global warming, mainly CO2, as being a problem, or when negative impacts on weather and the biosphere started to be observed. The question of when the general public started to understand that this was a problem is not, in my view, an interesting one since it’s a pretty arbitrary benchmark and indeed many still don’t. I’ve seen recent surveys that indicate that many not only don’t understand the science, they don’t even know what the basic scientific consensus is on the major issues.
The timeline posted by TroutMan in #4 is a pretty good one, and one can go through it and make one’s own judgment about when the science became pretty much conclusive. Clearly it wasn’t in 1971, when the SMIC (Study of Man’s Impact on Climate) conference was held and called for the start of major research. The SMIC conference was important because it was broadly international and it led in the following year to the formation of UNEP, the UN Environment Programme, which later led to the formation of the IPCC.
However the timeline fails to mention another important milestone on the domestic front, namely that in 1975 the National Research Council of the US National Academy of Sciences issued a formal report outlining an ambitious program of climate research, and it was in the following years that the science really started to get underway on a large scale. The period between 1975 and the first IPCC report in 1990 was a period of enormous scientific productivity and marked the beginning of the consolidation of scientific consensus on the major issues: where was the climate heading, and to what extent human activities are responsible.
In my view the third IPCC report in 2001 marked the first time that words like “unequivocal” and “incontrovertible” were being widely used to describe the consensus of the scientific literature on anthropogenic global warming. This also marked, in my view, the beginning of a political counterculture dedicated to questioning and opposing the scientific findings. It was at around this point, when the scientific findings were strong enough to justify actionable public policy, that the issue started to become strongly politicized by these groups and the science mischaracterized as a “debate”.
As for when negative impacts began, there are so many different indicators with different degrees of direct and indirect relationships to climate change that it’s impossible to pin down a definite timeframe, but here’s a general observation. Global CO2 emissions have been progressively increasing throughout the 20th century and still are. Accumulated levels began to be sufficiently elevated to start affecting the climate somewhere around the mid- to late first half of the 20th century, but at the same time relatively dirty industrial processes and vehicle engines were polluting the air with sulphate aerosols – the stuff that would later be associated with acid rain – and other particulates. These had the effect of masking the CO2 warming for nearly four decades at around the mid-point of the century.
At around the mid- to late-70s, the combination of fewer particulate emissions and even more elevated CO2 saw the rest of the century dominated by the most rapid temperature increases ever seen in the instrumental record. Since the late 70s the loss of Arctic sea ice has accelerated dramatically, creating a feedback that’s driven Arctic temperatures up much faster than the global average. During this time we’ve been seeing unusual atmosphere and ocean circulation changes, more extreme weather events, more droughts and floods, and greater hurricane energies. We’re also seeing all kinds of impacts in the biosphere including crop losses in vulnerable regions and changes in wildlife habitats. So I’d put the second half of the 20th century generally, and the late 70s in particular, as the time that the first observable negative impacts started to manifest.
About 10,000 years ago. It was a big problem for the folks living in the Mediterranean and Baltic Sea basins
Moderator Note
Again, don’t post irrelevant comments in this thread. Per the OP, this question is about anthropogenic global warming since the 1800s.
Stick to the topic in the OP. Further comments of this kind may be subject to a warning.
Colibri
General Questions Moderator
You mean a threat to the environment, or a threat to the industries producing greenhouse gases. I don’t think the latter has really happened yet, but it’s getting closer.
In the 1820s, Joseph Fourier showed that the earth was warmer than could be accounted for by direct heating by the sun alone. He never proved why, but one of his theories was the atmosphere was acting as an insulator.
In 1859, John Tyndall accurately measured the infrared absorption properties of the main atmospheric gasses. This was the first proof of the greenhouse effect theory of global warming, though it had been widely discussed before that.
In 1896, Svante Arrhenius showed how changing levels of carbon dioxide in the atmosphere could change surface temperature, and estimated that a doubling of CO[sub]2[/sub] in the atmosphere could cause a 4C increase in temperature. That’s high by today’s estimates, which center around 3C, but it’s still possible. He was also possibly the first to counter the “climate is always changing” argument:
First time I’ve personally heard about it was somewhat at the end of the 70’s being a kid in Germany and by the middle of the 80’s it was all the rage in Germany.
1970 was apparently the year of the European Environment Protection.
For me it started to become mainstream news/topic with the scare of acid rain in the BlackForest (Link) killing all the trees, what causes it is and what we can do.
However, these were more environmental issues at the time of which Global Warming was/is part of.
Joseph Fourier discovered the greenhouse effect in 1824 and Charles David Keeling apparently was one of the first studying these effects in the US.
Climate Change: Warming Seen in Australia in 1940s, Research Says
Source: The timing of anthropogenic emergence in simulated climate extremes
It’s possible, of course, that global warming was already causing environmental problems even before anyone realized that it was happening. But to pin that down, we’d need to at the very least define what we mean by “problem”. There are probably some species that are extremely sensitive to temperature range, for instance, that were driven extinct (or at least extinct in some places) by temperatures moving out of that range… but the first species wiped out in such a way would have been ones that were right on the brink to begin with. And that might or might not be a problem for humans, depending on the economic impact of those species to humans and/or their perceived “cuddliness”.