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The headline of this post is bullshit. The author of the article doesn't prove "natural cycles" play small role. He claims that the data he analyses points to t

The headline of this post is bullshit. The author of the article doesn't prove "natural cycles" play small role. He claims that the data he analyses points to the conclusion one specific 60-70 year old cycle of oceanic origin has far less impact on climate than commonly accepted. He talks about one mechanism, there are plenty of other natural mechanisms that affect the climate in various ways. Quoting the article: >This means that ocean cycles on timescales of 60-70 years are unlikely to be a factor in the observed evolution of global temperatures since 1850. Instead, external factors, such as periods of strong volcanic activity and the release of aerosol particles (air pollution), have caused temperatures to fluctuate.

ocschwar 7y ago
There are other cycles, most of which are right now in a cooling phase, and yet we are warming. So those cycles (i.e. Milankovich cycles) can be written off already
- lowken10 7y ago
  We are still coming out of an ice age. So you comment is false.
- Jill_the_Pill 7y ago
  Or, rather than written off, treated as mitigating factors.
- User23 7y ago
  Plate tectonics are another huge factor. When Pangea existed there was just one ocean to distribute heat and no polar continent for glaciers to form on and increase the Earth’s albedo. That meant a much warmer planet. The Quaternary glaciation is still ongoing because of those tectonic factors. Another fun fact is that the warmest period in human existence was the Holocene maximum about 8000 years ago[1]. Geology is a fascinating field and thankfully lets us look at climate through a lens that isn’t intensely politicized. [1] https://en.m.wikipedia.org/wiki/Holocene_climatic_optimum#/media/File%3AHolocene_Temperature_Variations.png https://en.m.wikipedia.org/wiki/Holocene_climatic_optimum#/m...
inflatableDodo 7y ago
If you look to the paper the article is about - 'A limited role for unforced internal variability in 20th century warming.' - it does seem to demonstrate that natural cycles play small role and the way it is set up it doesn't have to look at all natural cycles to do that. >Using a two-box impulse response model, we demonstrate that multidecadal ocean variability was unlikely to be the driver of observed changes in global mean surface temperature (GMST) after 1850 A.D. Instead, virtually all (97-98%) of the global low-frequency variability (> 30 years) can be explained by external forcing. We find similarly high percentages of explained variance for inter-hemispheric and land-ocean temperature evolution. edit - link to paper - https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555.1?af=R& https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555....
- taneq 7y ago
  It still seems ass-about to me. The study doesn't show that natural cycles don't do much, it shows that in our models the external forcing they added is sufficient to cause the observed results. We already know there's more going on than our models account for (consider the post-9/11 discovery of global dimming from airliner exhausts, as one example). There are probably a heap of effects pushing the measured temperatures in each direction that we don't yet know about. (Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.)
  - inflatableDodo 7y ago
    >(Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.) Well it can't, can it? All it can do is provide evidence one way or another. Now if you think that there is a problem in the model they are using, could you point to it and explain the specific issue? I assume that it is somewhat updated since 9/11 and I also suspect that aerosol effects of airliner exhausts will have been known about to the subject of atmospheric physics, 9/11 will have just given some solid numbers. Which are now presumably in the models.
joe_the_user 7y ago
Yes, the headline is rather self-defeating. I studied persuasion techniques before the Internet got big and one of the trendy manipulation approaches then was to write an article titled "Why XXX" when XXX is some assertion you make, perhaps even with evidence but for which you don't actually offer an explanation (the reader never discovers why XXX, they are only that XXX is true, and why XXX is generally something people would be curious about). This technique naturally has become an arrow in the quiver of click-baiters but with click-bait sooo big now, using such bullshit is more likely to hurt a serious article than help it. The proper title would be "we show human-generated carbon is sufficient to explain climate for the X many years", a significant claim by itself.
radford-neal 7y ago
From my initial glance at the post and paper, they seem to be claiming that the factors they do look at account for almost all the variation. If this is a correct attribution, then there can't be big role for any other factors, known or unknown. Now, it's easy to fool oneself in this sort of modelling exercise - by fitting lots of parameters to the data, one can seem to account for lots of variation, without actually capturing the true relationship. I haven't looked at the paper in detail yet, so I can't say whether or not they avoided this pitfall.

ocschwar 7y ago

There are other cycles, most of which are right now in a cooling phase, and yet we are warming. So those cycles (i.e. Milankovich cycles) can be written off already

lowken10 7y ago
We are still coming out of an ice age. So you comment is false.
Jill_the_Pill 7y ago
Or, rather than written off, treated as mitigating factors.
User23 7y ago
Plate tectonics are another huge factor. When Pangea existed there was just one ocean to distribute heat and no polar continent for glaciers to form on and increase the Earth’s albedo. That meant a much warmer planet. The Quaternary glaciation is still ongoing because of those tectonic factors. Another fun fact is that the warmest period in human existence was the Holocene maximum about 8000 years ago[1]. Geology is a fascinating field and thankfully lets us look at climate through a lens that isn’t intensely politicized. [1] https://en.m.wikipedia.org/wiki/Holocene_climatic_optimum#/media/File%3AHolocene_Temperature_Variations.png https://en.m.wikipedia.org/wiki/Holocene_climatic_optimum#/m...

inflatableDodo 7y ago

If you look to the paper the article is about - 'A limited role for unforced internal variability in 20th century warming.' - it does seem to demonstrate that natural cycles play small role and the way it is set up it doesn't have to look at all natural cycles to do that. >Using a two-box impulse response model, we demonstrate that multidecadal ocean variability was unlikely to be the driver of observed changes in global mean surface temperature (GMST) after 1850 A.D. Instead, virtually all (97-98%) of the global low-frequency variability (> 30 years) can be explained by external forcing. We find similarly high percentages of explained variance for inter-hemispheric and land-ocean temperature evolution. edit - link to paper - https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555.1?af=R& https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555....

taneq 7y ago
It still seems ass-about to me. The study doesn't show that natural cycles don't do much, it shows that in our models the external forcing they added is sufficient to cause the observed results. We already know there's more going on than our models account for (consider the post-9/11 discovery of global dimming from airliner exhausts, as one example). There are probably a heap of effects pushing the measured temperatures in each direction that we don't yet know about. (Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.)
- inflatableDodo 7y ago
  >(Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.) Well it can't, can it? All it can do is provide evidence one way or another. Now if you think that there is a problem in the model they are using, could you point to it and explain the specific issue? I assume that it is somewhat updated since 9/11 and I also suspect that aerosol effects of airliner exhausts will have been known about to the subject of atmospheric physics, 9/11 will have just given some solid numbers. Which are now presumably in the models.

joe_the_user 7y ago

Yes, the headline is rather self-defeating. I studied persuasion techniques before the Internet got big and one of the trendy manipulation approaches then was to write an article titled "Why XXX" when XXX is some assertion you make, perhaps even with evidence but for which you don't actually offer an explanation (the reader never discovers why XXX, they are only that XXX is true, and why XXX is generally something people would be curious about). This technique naturally has become an arrow in the quiver of click-baiters but with click-bait sooo big now, using such bullshit is more likely to hurt a serious article than help it. The proper title would be "we show human-generated carbon is sufficient to explain climate for the X many years", a significant claim by itself.

radford-neal 7y ago

From my initial glance at the post and paper, they seem to be claiming that the factors they do look at account for almost all the variation. If this is a correct attribution, then there can't be big role for any other factors, known or unknown. Now, it's easy to fool oneself in this sort of modelling exercise - by fitting lots of parameters to the data, one can seem to account for lots of variation, without actually capturing the true relationship. I haven't looked at the paper in detail yet, so I can't say whether or not they avoided this pitfall.