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Tidal energy is not renewable
191–200 of 350 posts
Re: Tidal energy is not renewable
#192Earlier quoted context omitted.
That’s about the density of Kowloon walled city. And ignores the available space in the ocean.
Did they grow any food, produce electricity, or had any manufacturing at all in Kowloon?
To be clear, "Kowloon" is different from "Kowloon Walled City". And, yes, they did have very small manufacturing inside.
I highly recommend that you find a copy of this (in)famous book about it: > (https://cityofdarkness.co.uk).
Re: Tidal energy is not renewable
#193The single most important assumption in this paper is that energy consumption will increase by 2% per year. This kind of exponential growth leads to outlandish estimates for the amount of tidal energy that society will demand. Energy consumption has decoupled from population growth rates and economic growth. How much energy will we consume in 1,000 years? Most projections of the population have it stabilizing at arou…
With this analysis no energy source is renewable, and we'd even run out of sunlight (or surface area that can be dedicated to solar power anyways, or see demand exceed solar power were we to put solar panels on every square inch of the planet's surface).
In reality we're already certain to hit a population maximum in just two+ decades, and not only that but the world is very likely to be on a negative population growth curve after that for some time. And we're going to need some new tech revolution to drive energy demand in developed countries up much more than it is, and the developing world's per-capita demand will not likely exceed the developed world's once fully developed.
I.e., we're not growing forever, the end of population growth is around the corner, and the end of energy demand growth is not much further.
Re: Tidal energy is not renewable
#194Earlier quoted context omitted.
More countries are now sub-2.0 replacement, China is down to 1.09 so the peak is unlikely to get much more than that.
The trends are mostly encouraging but there are still 102 countries with a fertility rate above replacement rate, so we’re not out of the woods yet: https://en.wikipedia.org/wiki/List_of_countries_by_total_fer...
Unless those countries have increasingly western lifestyles, stable political systems and growing economies, then it actually doesn't matter. The grim reality is that all those places have substantial modifiers on their death rates, and aren't exporting their increasing population to the world in any meaningful way.
We know from experience that if those places actually started to improve, then the birth rate would drop precipitously.
Re: Tidal energy is not renewable
#195I'm not sure the author realized this, but they're actually making a statement about how crazy exponential growth is. Not about the sustainability of tidal power. This becomes obvious once you look closer at what that 2% growth rate (as assumed in the post) implies. Our global energy consumption in 2008 was estimated to be 474 exajoules. The total energy received by the earth from the sun during a year is about 5 mil…
Human population growth is set to reach a peak in just two+ decades, and then will start declining for some time. Where we've seen fertility drop below replacement rate we've also seen that drop be persistent for decades, which means that population declines will accelerate before they arrest (if they arrest).
So this is a bit of much ado about nothing. We're not going to exceed low single digits percentage points of the energy reaching the planet from the Sun.
Heat dissipation is relatively easy if we use 1% equivalent of Solar energy on Earth: the water cycle can speed up in response to positive forcings and slow down in response to negative forcings. This is why the planet's climate has been so stable in the sense of being a random walk centered on an optimum that supports the sort of life that we have on the planet. Similar observations explain Mars' and Venus' inhospitability: there's not enough atmosphere, much less liquid water on Mars to drive a similar thermostatic system, while Venus' climate is pegged at a maximum, with albedo as high as it can reasonably go, and it can't cool itself significantly with anything like a water cycle.
Re: Tidal energy is not renewable
#196A related question I think about from time to time. If our energy consumption grows, how soon we will destabilize the Earth?
Even 100% clean energy, if infused into the system may increase temperature, or speed up circulation of currents, and other effects.
Of course, it's not nesessary all energy goes into temperature. Some can be conserved, e.g. as chemicals.
But in general, the more energy we have in our disposal, the more potential for damage.
We will dig deeper, smelt more ore, etc, etc.
Re: Tidal energy is not renewable
#197Hmm so if we pump water to amplify the tides we can speed up the Earth's spin and get rid of the leap second.
We should draw tidal power until there are exactly 360 days in a year, to make the arithmetic nice, and incidentally give us 24 minutes extra sleep.
Re: Tidal energy is not renewable
#198Earlier quoted context omitted.
The problem with this, or any other hypothetical "decoupled growth" argument is that, well, it's purely hypothetical. There's no evidence whatsoever that economic growth can be decoupled from resource, and most especially energy, usage. There are instances of increased efficiencies , which thanks to the Jevons Paradox increase overall resource utilisation (economically, efficiency is equivalent to a reduced price, an…
Conversely the people who argue against growth never have any answers they want to elaborate on. They have "well we can't have endless growth" and that's where the conversation stops. They never want to examine the consequences of that thought (no growth means we're into a zero-sum game) or whether they think we're even plausibly close to the limit (instead they want to have a proxy argument about environmental damag…
I'd really like to see you point to specific instances of this.
I could point to any number of examples refuting this, but really prefer you lay your cards on the table first.
Re: Tidal energy is not renewable
#199Earlier quoted context omitted.
Aviation historically, has not gotten cheaper overtime. If anything, it is more expensive. Only rich people had planes 100 years ago and only rich people own them now and the trend line doesn’t indicate it’ll be different in another hundred.
Nobody owned a 747 a hundred years ago. Cheapest flight I've ever taken was 9.99 from Berlin to London — not sure if pounds or euros, but does it matter when either way it is less than I used to spend on a week of school lunches nearly 20 years earlier?
Exceptions like 10 EUR flights aren't sustainable. They're just auctioning off empty seats to cut costs.
The comparison was conceptual thing to similar thing. Only the rich own and operate private planes, that hasn't changed. The fact that other, more sophisticated planes exist doesn't undermine the point.
There are also diminishing returns. And past leaps in lifestyles aren't guaranteed to continue the same trends, and can reverse.
The earth has seen several major extinction events. Arguably humans are the cause of the latest one. Doubtful we can sustain billions of us without an ecological system to produce our bare necessities, certainly not enough for a full life.
Re: Tidal energy is not renewable
#200Earlier quoted context omitted.
Almost every human population is under strong selection pressure towards having more people. This dip in fertility cannot and will not last.
Unless external factors kick in, like depletion of resources and soils. There's no any law of nature that says homo sapiens must be able to survive. Smaller scale examples are: 1. Easter island -- we, humans, deforested the island, that degraded and depleted human population significantly even before the first european ships discovered the island. From what I've heard, "Rapa Nui" movie is unusually historically corre…
> Easter island -- we, humans, deforested the island, that degraded and depleted human population significantly even before the first european ships discovered the island.
More recent research shows that this is probably not true - there's evidence that the population was growing right up until the arrival of Europeans[1].
[1] https://www.sciencedaily.com/releases/2021/07/210713090153.h...