Article in Nature On Global Temperature variability

In summary: UK's Natural Environment Research Council. In summary, the article discusses the latest research on equilibrium climate sensitivity and how it has been updated to account for the inaccuracy of past climate models. The paper finds that the likelihood of ECS being greater than 1.5 degrees Celsius is very low, and that global warming needs to be slowed down in order to avoid drastic consequences.
  • #1
Evo
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Interesting Article in Nature and looks like better news (as opposed to doom and gloom) things may not be as bad as previously predicted. It will be interesting to follow further research as we gain more data and produce more accurate climate predictions.

Emergent constraint on equilibrium climate sensitivity from global temperature variability

Abstract

Equilibrium climate sensitivity (ECS) remains one of the most important unknowns in climate change science. ECS is defined as the global mean warming that would occur if the atmospheric carbon dioxide (CO2) concentration were instantly doubled and the climate were then brought to equilibrium with that new level of CO2. Despite its rather idealized definition, ECS has continuing relevance for international climate change agreements, which are often framed in terms of stabilization of global warming relative to the pre-industrial climate. However, the ‘likely’ range of ECS as stated by the Intergovernmental Panel on Climate Change (IPCC) has remained at 1.5–4.5 degrees Celsius for more than 25 years1. The possibility of a value of ECS towards the upper end of this range reduces the feasibility of avoiding 2 degrees Celsius of global warming, as required by the Paris Agreement. Here we present a new emergent constraint on ECS that yields a central estimate of 2.8 degrees Celsius with 66 per cent confidence limits (equivalent to the IPCC ‘likely’ range) of 2.2–3.4 degrees Celsius. Our approach is to focus on the variability of temperature about long-term historical warming, rather than on the warming trend itself. We use an ensemble of climate models to define an emergent relationship2between ECS and a theoretically informed metric of global temperature variability. This metric of variability can also be calculated from observational records of global warming3, which enables tighter constraints to be placed on ECS, reducing the probability of ECS being less than 1.5 degrees Celsius to less than 3 per cent, and the probability of ECS exceeding 4.5 degrees Celsius to less than 1 per cent.

Unfortunately, the article itself is behind a paywall, but addresses the inaccuracies of prior climate models.

https://www.nature.com/articles/nature25450


Not a huge fan of Science Daily, but for those without access to the full Nature article, it has explanations of the data from the paper's authors.

https://www.sciencedaily.com/releases/2018/01/180117131132.htm
 
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This paper is due to the fact the someone allowed and funded research, instead of cutting it off.
 
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  • #3
jim mcnamara said:
This paper is due to the fact the someone allowed and funded research, instead of cutting it off.
Thank goodness for that!
 
  • #4
Evo said:
addresses the inaccuracies of prior climate models.

Does it address inaccuracies - if "inaccurate" is even the right term? Have most previous climate models been shown to be significantly inaccurate? I'm not so sure that is the case, with many of the claims they are "wrong" based on differences between a midrange average of many model runs - where variability is averaged out to a degrees per decade figure - and the real world where the variability year to year and decade to decade is present in all it's glory.

This is one paper using a different approach, yet to be dissected by scientific peers, that appears to find less likelihood of the extremes but has midrange climate sensitivity near to that of many other estimates. It is unlikely that this paper alone delivers certainty. The "better news" description may be premature and does not alter the fact that failure to act to reduce emissions aggressively - when major governments currently work hard to avoid doing so - is very likely to still lead to "bad news".
 
  • #5
More accurate data, IMO, is a positive thing. As I stated, it will be interesting to follow further research. And the authors encourage CC to be of concern and continue to be addressed.

From the SD article
Explaining the significance of the results, Professor Cox added: "Our study all but rules-out very low or very high climate sensitivities, so we now know much better what we need to. Climate sensitivity is high enough to demand action, but not so high that it is too late to avoid dangerous global climate change."
 
  • #6
Evo - I'm just a bit wary of statements like "all but rules-out" - I'd like to think that level of confidence is warranted and look forward to the considered opinions of other climate scientists about this methodology. Yet paleo-climate studies - the nearest we have to real world experiments - tend to show higher sensitivity.
 
  • #7
Ken Fabos said:
Evo - I'm just a bit wary of statements like "all but rules-out" - I'd like to think that level of confidence is warranted and look forward to the considered opinions of other climate scientists about this methodology. Yet paleo-climate studies - the nearest we have to real world experiments - tend to show higher sensitivity.
It sounds like you're disappointed that there wasn't more "gloom and doom".
Are you aware who Peter Cox is? He was a lead author on the IPCC report, he led a crusade for CC before the Paris talks. He's a Climate scientist and professor of climate systems dynamics at the University of Exeter. Based on his history, I would tend to believe him when he says things may not be as bad as previously presumed.

Some of his previous talks, I actually shouldn't post these as they are getting more into politics and away from the science, so these are not for discussion, just for background on him.


 
  • #8
Interesting article evo, thanks for bringing it up.

My reading of it is that the ECS parameter is now more confidently known in such a way that the 66% confidence interval is now tighter than it was in the previous IPCC report. In fact the maximum likelihood value of ECS is about the same (around 3 deg C) as it was before, but the chances that it is high (e.g. 4.5 deg C) are slimmer according to this study than the previous IPCC report. On the other hand the chances that it is low (e.g. 1.3 deg C) is also reduced in the new study. So in effect the "best case" and "worst case" scenarios from the IPCC report are both less likely.

It is good news that the "worst case" ECS parameter is reduced. However ECS is not the only thing that controls climate. We should be wary of other factors and not rest on our laurels.
 
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  • #9
Evo said:
Unfortunately, the article itself is behind a paywall, but addresses the inaccuracies of prior climate models.

I don't think it "addresses the inaccuracies of prior climate models". It looks at variance in an ensemble of prior climate models with known ECS parameter to establish a relationship which is then used to estimate the true ECS parameter.
 
  • #10
billiards said:
I don't think it "addresses the inaccuracies of prior climate models". It looks at variance in an ensemble of prior climate models with known ECS parameter to establish a relationship which is then used to estimate the true ECS parameter.
Could be, in searching for articles about the paper this is how several explained it when they went into more detail. The SD article I chose to post left that out and just went forward, as I (in hindsight) should have.
 
  • #11
Evo said:
It sounds like you're disappointed that there wasn't more "gloom and doom".

Not so - rather that it is a single study with a different approach, that may well reduce the uncertainty - but I suggest that it is premature to be certain of that. I would note that most climate models - and this study relies upon those models - do have significant omissions, including carbon feedbacks that we can expect will release more GHG's from oceans and soils and result in warming that is not currently included.
 
  • #12
Ken Fabos said:
Not so - rather that it is a single study with a different approach, that may well reduce the uncertainty - but I suggest that it is premature to be certain of that. I would note that most climate models - and this study relies upon those models - do have significant omissions, including carbon feedbacks that we can expect will release more GHG's from oceans and soils and result in warming that is not currently included.
Well, we can't guess about things here, so we will have to wait until further studies come out.
 
  • #13
The article says there is a probability of 66% that the warming will be 2.8 ± 0.6 K with a doubling of CO2 concentration.
 
  • #14
Posts without proper peer reviewed links have been deleted.
 
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1. What is the main finding of the article?

The main finding of the article is that global temperature variability has increased significantly over the past century, and this trend is likely to continue in the future.

2. How was the research conducted?

The research was conducted by analyzing data from various sources, including temperature records from thousands of weather stations around the world, satellite measurements, and climate models. The data was then analyzed using statistical methods to identify trends and patterns in global temperature variability.

3. What factors contribute to global temperature variability?

There are several factors that contribute to global temperature variability, including natural phenomena such as volcanic eruptions and solar activity, as well as human activities such as greenhouse gas emissions and land use changes. These factors can affect the Earth's climate and cause temperatures to fluctuate over time.

4. What are the potential impacts of increasing global temperature variability?

The potential impacts of increasing global temperature variability include more frequent and severe extreme weather events, such as heat waves, droughts, and hurricanes. It can also lead to changes in ecosystems, agricultural productivity, and human health.

5. What can be done to mitigate the effects of global temperature variability?

To mitigate the effects of global temperature variability, it is important to reduce greenhouse gas emissions and promote sustainable practices. This can include transitioning to renewable energy sources, improving energy efficiency, and implementing land management strategies that help to sequester carbon. Additionally, individuals can take actions such as reducing their carbon footprint and supporting policies and practices that address climate change.

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