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RE "constant amount of sunlight", this is actually untrue. The suns energy output is increasing roughly 10% per billion years. So it's actually never been stronger. It also means that we have much less habitable time on earth than we thought


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Except it hasn't. Solar irradiance has steadily increased over billions of years, and fluctuates regularly with the solar cycle. I'm not saying that this couldn't have unexpected consequences, but you can't start from the premise that solar irradiance has always been constant.

It's a bit absurd the idea that humans living on earth are going to produce more energy than the Sun.

Maybe I'm naive and simple minded. But that just seems insane.

If I'm doing the math right, at 2.3% growth = we produce more energy than the Sun in 4500 years.

It doesn't matter how many years it is. It's never happening.

Just look at how damn hot and inhospitable the sun is. We're not producing more energy here!

It'd be infinitely more plausible to build a Dyson sphere around the Sun, and call me naive on that, too, but I'm skeptical that's ever gonna happen either.


Haven't there been some studies about sun output? That seems natural?

The sun has a power output per volume of a compost. Quite literally.

We need more :-)

Edit: Saw another comment explaining this now. The sun is really very slow. But it has been around for billions of years.


From the perspective of users of solar energy on Earth, wouldn't an increase over billions of years appear constant? My intuition tells me that evolution is much faster than that, and any fluctuations due to solar cycle dynamics would already be mitigated as expected by the same process, if it is indeed so regular.

Keep in mind that solar output itself has steadily increased since the eocene.

> What does that mean that "the sun is brighter"?

Sun gets about 8% brighter (8% more energy output) every 1 billion years.


> the sun was about 20% dimmer back then

According to wikipedia[1], the Sun increases in brightness steadily about 1% every 100M years, yet we had CO2 levels 10 times higher than now about 500M years ago.

[1] https://en.wikipedia.org/wiki/Solar_luminosity


Solar luminosity goes up 1% every 100 million years roughly.

This. The energy output of the Sun is legit ridonculous.

Something along the lines of 1 or 2 all the energy ever consumed by humans since forevers per second.


So if our energy consumption increases by 4% per year (current global average) for ~110 years, we'd need to capture / produce as much energy as the Sun hits us with. Crazy!

The sun has no infinite supply of energy.

The sun is also better than a fusion reactor on earth by only a constant factor. That alone doesn't mean much for out prospects of matching its power output.

There's an amount of energy being shot at the planet by the sun every day. Human civilisation uses a lot less than a percent of that.

Another fun fact: the power output of the sun is 4 * 10^26 Watts.

The sun is a good source of power.

The sun is literally shining brighter, in that it produces more energy

On the other hand, at a fixed doubling period of 35 years (i.e. assuming 2% yearly growth) we'll get at that "one extra sun" level in only 500 years.

Or if we take "5% of an extra sun" as the problematic power output, it will take only 150 years.

(Now consider that in the golden age of oil before the oil shocks in the seventies, oil consumption was growing more like 8% per year.)


I'm not following your rebuttal here. s1artibartfast says that the sun can provide much more power than we currently consume. The limit from your link from earlier is not a limit on how much power the sun can provide, but rather a limit on how much power we can produce before we produce too much CO2. With power production methods that produce less CO2, we won't run into that limit, and we obviously won't run into the solar energy limit.
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