Earth gets over 170,000 terawatts of solar energy every day—10,000 times more than humanity uses. Losing just a fraction of our cloud cover means a massive, invisible throttle is coming off the climate system. If this trend holds, we’re not just warming—we’re stepping on the gas.
Units provided were power not energy. The number provided is just the product of the solar constant and the cross-sectional area of Earth [0], roughly.
I like the use of watts/day instead of joules here because we have some intuition about watts. Earth must dissapate 170 exawatts per day of sunshine, in addition to letting off some amount of heat from the molten core.
(Life has evolved on the edge of a knife, at the narrow balance point between enormous energies that cancel out just so. I often think that at the beach, looking out across the ocean, marveling that the water is almost never sloshing around at any scale proportional to itself. It's up to us to educate those who don't understand positive feedback loops and the existential risk they present to any system in equilibrium.)
Your comment still reads like watts are energy, which they are not. Maybe you mean "watt-days instead of joules". Watts/day is nonsense, and joules/day are watts. (With some coefficient)
I don't see what's wrong about OP's use of the term in the context they are using it. In the context given the number of days in the denominated unit is 1. Which means as dividend or factor it is going to give you the same result. Again in this context watts per day is much more intuitive for most people too reason about.
I don't mean to be rude, but anyone who thinks watts/day and watt days are ever interchangeable will have severe problems reasoning about anything electricity-related or energy-related.
It is akin to thinking that "2 apples" and "an apple divided by 2" are interchangeable because both expressions involve the concept of an apple and the number 2.
> over 170,000 terawatts of solar energy every day
i'd definitely rewrite it myself, but it's also a correct way to specify that there are no days of the week, year, or whatever (solar cycle) in which the terawattage is below 170k. Not very intermittent, is it!
I think we may be talking at cross purposes. I specifically used the number one because it behaves like a unit here. unlike 2 or any other number, 1 is also the standard 1D unit vector, so 1apples is indeed the same quantity as apples/1, but because it is a unit we usually imply its presence rather than express it explicitly as above.
watts/unit thus seems fine to me, whatever the unit may be, even if it itself is derived from time. watts per day would just work out to joules/second/1/24*60*60, making 1 watts per day a derived unit that expresses joules/84600 seconds, or an instantaneous rate of one 84600th of a joule.
[edit: The earth receives 14.9 ZettaWatts of solar power per day, and 173 Petawatts per second, I was reading it as 173 PW over a day, in which case the above works fine. Mea culpa]
Yeah the units cancel, that's the issue. The phrasing implies that after half a day it's received 85k terawatts which doesn't make any sense.
Power (kg m^2 / s^3) * Time (s) = Energy (kg m^2 / s^2)
Now from context it's obvious that what was meant is that Earth continually receives 170 terawatts from the sun. The phrasing is technically inaccurate, but it's a turn of phrase that works fine.
So, not knowing any better, I read it as meaning 170k TW/day, so 85k TW/12 hours made sense to me, but you’re right… [1]. The earth receives 14.9 ZettaWatts of solar radiation per day…
No they don't, you need to divide, not multiply just like you would with every other unit. 1l of rain every day is 1l/day, not 1l * day
. Which means Watt per day is J/s^2
If you want to be nitpicky about semantics, I think the only valid interpretation then is to take OP by their words and assume they meant energy transfer for 24h, since they did not write "per day" as you suggest:
"Earth gets over 170,000 terawatts of solar energy every day"
= 170 PW × 1d
= 170 × P(J/s) × 86.4 × ks
= 170 × 10¹⁵ × (J/s) × 86.4 × 10³ × s
= 14.6 × 10²¹ × J
= 14.6 ZJ
However, I also think "of solar energy" could be read as specifying the type of energy for the "rate of energy transfer", which is already implied in 'watt'. And since it's related to energy usage (rate), there really is no need to leave the "rate of energy transfer" interpretation at all and get hung up on "energy vs. power":
"Earth receives 170 petawatts as solar energy - 10,000 times the energy humanity uses, at any moment.
That’s changing “every day” into “per day”. Judging by the downvotes that is how people are reading it, but “specified time” of a rate-quantity is an integration, to me. Which makes it a multiply op over the time specified.
If you pour out one bucket of sand every hour, and you do that for 10 hours, I expect the quantity of sand to be measured in buckets.
No we are not, and a brief look at the history of the planet will show that. We're driving most of the changes today, but the planet itself also changes on it's own (tectonic shifts, for one), as do extra-planetary factors (solar cycles), and both of these impact our upper atmosphere.
From the article, there's significant uncertainty what's driving the currently measured effect:
> Climate scientists now need to figure out what’s causing these cloud changes.
> The team also found that 80% of the overall reflectivity changes in these regions resulted from shrinking clouds, rather than darker, less reflective ones, which could be caused by a drop in pollution. For Tselioudis, this clearly indicates that changes in atmospheric circulation patterns, not pollution reductions, are driving the trend.
> But Loeb, who leads work on the set of NASA satellite instruments called Clouds and the Earth’s Radiant Energy System, which tracks the energy imbalance, thinks pollution declines may be playing an important role in the cloud changes, especially in the Northern Hemisphere. “The observations are telling us something is definitely changing,” he says. “But it’s a complicated soup of processes.”
To your point, however, we do appear to be the only ones capable of intentionally modifying the environment, so if anybody's going to understand and address this, it'll be us.
These types of comments are pointless. We are destroying the world. Ok. What’s the solution? All involve pain, but no one wants to talk about that. Tech isn’t going to solve it. For one, the kind of person on this site is contributing literally 10000x more to the issue than the worlds bottom, so we can start there.
People love tech solutions, because then they don’t have to stop consuming and live modestly.
Most likely mass migration from the equator into the colder north or geoengineering. It's already overly hostile for over a billion people with the 1.4C warming we've had. School closures for multiple weeks a year, difficulty working outside. The human body did not evolve for these wet bulb temperatures.
If we immediately stopped all CO2 and methane emissions, the problem wouldn't be solved. There's still more warming that's going to happen as a result of the past emissions.
True. The warming we see today is from emissions years ago. The inertia is real.
But even if we would spend only the explicit subsidies we would have a trillion dollar each and every year to spend on things like carbon capture and other mitigations which are not dangerous large-scale geoengineering projects like cloud seeding.
I don't necessarily agree with GP's comment but they do have a valid point.
> We could solve this problem in a few years with technology if we really wanted to.
Everybody wants to solve the problem with technology. What if, the solution is just plain old hard work like planting trees, conservation, better recycling, better laws that help in saving ecosystem. But who would do that. So let's keep on creating problems with technology and then solve them with more technology.
Anything that facilitates or requires extracting carbon from the ground: Coal plants, petrol engines, cars, airplanes, mass production, modern agriculture processes.
The only way to stop global warming is to stop extracting carbon from the ground, where it's stored. After that we can think about capturing carbon. But first if all we need to stop pumping it into the atmosphere at a faster rate than the earth can absorb it (about 40% is absorbed at the moment, 60% of all human carbon use is added to the atmosphere).
Yes, what do you mean? The biggest climate effect at the moment is human carbon use, which is changing weather patterns, and the cause of the cloud shrinkage is changing weather patterns => cloud shrinkage is driven, to some degree (I would guess strongly, but let's be careful, so some degree) by human carbon extraction.
Not without pain, nope. Reality is the world’s rich are the culprits. If they stop consuming problem solved. No amount of angry downvotes will change this basic fact.
People will learn to live modestly, voluntarily or by force.
Just to be clear though: "the world's rich" here doesn't mean "billionaire CEOs" that a lot of people think of. It means the average American and European.
We'd be well net neutral and way positive on the just/unjust scale with just two fucking changes.
Get rid of the millionaires excessive destructive power (both structural/political and the personal excessive consumption) and by eliminating factory animal agriculture.
Neither would diminish well-being. At least the actual. Some ego/envy issues though as narcissistic "successful" people couldn't feel their power, but I'm willing to sacrifice that for my kids future.
The benefits are many fold as per Durkheim and more recently Wilkinson and Pickett have shown us.
