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Death by hockey sticks

dothemath.ucsd.edu

81–90 of 143 posts

Re: Death by hockey sticks

#81

You can't make hockey sticks out of just a few data points, as this author does in several of the charts. For example, the deforestation chart is based on a few data points from a UN study (where Our World in Data that the author links to cites as its source). But tree coverage has actually increased over the past 30 years according to some studies by NASA and elsewhere. For example, one 2018 paper from Nature says:…

The author also mentions that their forest cover graph is "old growth", and even claims that this strengthens their point! So if I plant a tree today, or did so 30 years ago, this does not count against their deforestation graph, even though the tree exists, this somehow makes their plot more accurate.

Re: Death by hockey sticks

#82
Every hockey stick is the beginning of a logistic curve (if you are optimistic), or a bell curve (if you are less optimistic). Exponential growth is impossible given limited resources.

Re: Death by hockey sticks

#83

For a 500 page version of this analysis with correspondingly more rigor (including an acknowledgment of S-curves), see Growth by Vaclav Smil. Although this is just a tiny, flawed snapshot of the argument, the conclusions are the same.

The good thing about this type of fossil fuel fan fiction is that it's self-refuting.

They put all that effort into saying "energy made us rich" so implying we must worship fossil fuels. But as soon as the cost curves cross over the argument switches and works against them.

So then they need to argue that its not actually cheaper, its just a conspiracy to deceive you while even fossil fuel producers, corporate and state, are saying the opposite.

Re: Death by hockey sticks

#84

Earlier quoted context omitted.

Yeah the worst thing is that with the extinction rate, he states that he implicitly sets the background extinction rate to 0 in the year 1000. This is going to bias his 3-point curve fitting even moreso. The background extinction rate in the absence of humans is probably much higher than 0. New species are also continuously emerging while others are going extinct, so that the total number remains steady.

You are kinda arguing against your point. Around the year 1000, it's a reasonable guess to assume that emergence of new species and species extinction were roughly in balance, so net extinction rate was indeed around 0. Today, it's well-established that this net extinction rate is as horrible as is described. A few new species emerging here and there are not enough to compensate for the mess that we are causing on th…

I might have not expressed myself well in the previous comment, but when I say that "New species are also continuously emerging", it is to prove that the background extinction rate is not zero, not that we don't have a problem.

The curve that he fitted is not the net extinction rate. It's simply the total number of extinctions.

The graph he plots shows the total number of extinctions at year 1000 being 0 or almost 0. This is an assumption. In the absence of humans the extinction rate could be 1,2,10 per year, whatever, it's some small number. The point is that when you are fitting an exponential curve to 3 data points, the resulting curve will be very sensitive to small changes in the value of that point at year 1000. In particular, choosing a value of 0 will force the model towards the steepest possible gradient that the model can allow. i.e. it's biased towards alarmism.

EDIT: Although, when I think about it a little more, a reasonable model would model the extinction rate as an exponential plus a constant value, which would change things. Though a reasonable model probably wouldn't assume an exponential model at all based on 2 data points

Re: Death by hockey sticks

#85

I hope this is overly pessimistic and under-analyzed. For example, the human population hockey stick graph doesn't show the dramatic drop in birth rates experienced by developed countries. We are on track to reach a global population maximum. And is the author too zealous in drawing hockey stick curves over any 2 or 3 data points? Is deforestation still accelerating? Any chance extinctions will decelerate?

It looks like he’s been at it for a while, but quick googling didn’t turn up any substantive rebuttal (of him/his blog). In this post he seems to be making a simplistic Malthusian argument—but we know population growth is not Malthusian. The trickier problem seems more to be: what happens when the hockey sticks flatline? When China’s population stops growing, will its economy also stagnate? What happens then? I look…

> When China’s population stops growing

To put this in context, here's what a recent article[0] from Fortune has to say:

> On Thursday, Yang Wenzhuang, the head of population for China’s National Health Commission, told a conference that the country’s population would start to shrink before 2025, according to state-run news outlet Global Times. Earlier forecasts expected the decline to begin in 2027.

[0] https://fortune.com/2022/07/25/china-population-decline-coll...

Re: Death by hockey sticks

#86

Another way to look at it is that it's life by hockey sticks. Literally. We have 8 billion people alive today. Which is about 7.5 billion more than before the population hockey stick was a thing. Not only life, but the good life. 90% of people today live a much better life than lords and kings lived 500 years ago.

Fitting username, when you pay the debt to the past, with debt from the future and completely ignore the present, things inevitably look great; until they don't for eternity.

Re: Death by hockey sticks

#87

> This, to me, is truly alarming from an ecological point of view: not only has the human population grown like gangbusters, but the level of affluence per person has soared by an even larger factor. The impact on our planet scales as the product of these two (essentially, the GWP curve from before). The argument that 'affluence' or 'quality of life' is a zero-sum game with nature seems to have become popular recentl…

[deleted]

Re: Death by hockey sticks

#88
I failed to read the full article as the warmup graph of human population is not the full story, and the conclusion is incorrect. We need to look at the full picture, and that is that we are on track to reach a stable human population of approximately 10 billion iirc. This is due to greater global education levels, and subsequent lowered birth rates. There is a fantastic book called factfulness that addresses this directly, and also calls into question the dramatic effect of graphs in isolation, and how they can ver much be S curves etc.

Re: Death by hockey sticks

#89
post #69
post #56

Earlier quoted context omitted.

For me, it's that it wil balance out in the end. We might have to suffer, but it will balance out. My hope is that most of us won't have to suffer that much before it balances out. Also, I do feel good about the direction we're going in. California, where I live, is banning the sale of new combustion engine cars by 2035. 2035 will probably have some very hot weeks here, but that we're getting laws like this is a good…

That is overly optimisic though, the Paris agreement was a minimal effort, California and all other governments are on track to fail miserably at following even that. Which means we are talking about a lot more than a "few hot weeks".

> the Paris agreement was a minimal effort, California and all other governments are on track to fail miserably at following even that.

Could you clarify what you mean by "on track"?

According to the Guardian[0], "California Governor Jerry Brown [issued] an executive order calling for the entire California economy to become carbon-neutral by 2045" and "In order to stay below the Paris climate threshold of 2°C global warming above pre-industrial temperatures, humanity must become carbon-neutral by around 2060 or 2070."

Are you saying that California looks like it will miss its target by 25 years?

[0] https://www.theguardian.com/environment/climate-consensus-97...

Re: Death by hockey sticks

#90

Earlier quoted context omitted.

We practice eugenics with almost every lifeform we have domesticated but refuse to do so with ourselves, just coz some guy with a funny mustache got it confused with muh white masterrace.

Wow that skidded off the beaten track quickly. Population controls !== eugenics Dominating animals is part of human nature / DNA. Not sure what we do about it. Stop eating meat probably becomes ahead of stop breading poodles.

Stopping meat consumption will likely have unforeseen consequences.
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