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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, inv
by kacesensitive 2y ago
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.
- dbacar 2y agoterawatt is not an energy unit.
- spacedcowboy 2y agoR̶e̶a̶d̶ ̶t̶h̶e̶ ̶c̶o̶n̶t̶e̶x̶t̶…̶ - A̶ ̶w̶a̶t̶t̶ ̶i̶s̶ ̶d̶e̶f̶i̶n̶e̶d̶ ̶a̶s̶ ̶1̶ ̶j̶o̶u̶l̶e̶ ̶p̶e̶r̶ ̶s̶e̶c̶o̶n̶d̶ ̶ A̶ ̶w̶a̶t̶t̶ ̶f̶o̶r̶ ̶1̶ ̶s̶e̶c̶o̶n̶d̶ ̶t̶h̶e̶r̶e̶f̶o̶r̶e̶ ̶e̶q̶u̶a̶l̶s̶ ̶1̶ ̶j̶o̶u̶l̶e̶,̶ ̶a̶ ̶m̶e̶a̶s̶u̶r̶e̶ ̶o̶f̶ ̶e̶n̶e̶r̶g̶y̶ - A̶ ̶T̶e̶r̶a̶w̶a̶t̶t̶ ̶f̶o̶r̶ ̶a̶ ̶d̶a̶y̶ ̶i̶s̶ ̶t̶h̶e̶r̶e̶f̶o̶r̶e̶ ̶a̶l̶s̶o̶ ̶a̶ ̶m̶e̶a̶s̶u̶r̶e̶ ̶o̶f̶ ̶e̶n̶e̶r̶g̶y̶.̶ [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] See: https://gosolarquotes.com.au/amount-of-solar-energy-hitting-earth/ https://gosolarquotes.com.au/amount-of-solar-energy-hitting-...
- treyd 2y agoYeah 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.
- deleted 2y ago[deleted]
- jessekv 2y agoso... close... petawatts ;)
- spacedcowboy 2y agoSo, 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… [1]: https://gosolarquotes.com.au/amount-of-solar-energy-hitting-earth/ https://gosolarquotes.com.au/amount-of-solar-energy-hitting-...
- deleted 2y ago[deleted]
- CorrectHorseBat 2y agoNo 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
- AlienRobot 2y agoI think a clearer example would be saying a car runs 20KM/H every day.
- gpderetta 2y agoOn the other hand batteries energy capacity is commonly rated in Watt hour. Watt*day is a perfectly cromulent energy statement although a bit misleading.
- Ekaros 2y agoWatt*day is weird, but at least unit of energy. Watts a day is not. Really common mistake in general to use kWh as a kW. Watthour is unit of energy. As watt is energy by time period. So you get back to units of energy. Technically watt/day could be change in power consumption.
- spacedcowboy 2y agoThat’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.
- jijijijij 2y agoIf 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. Edit: And let's be real, we all only feel very smart here because we just watched the latest Technology Connections video https://www.youtube-nocookie.com/embed/OOK5xkFijPc https://www.youtube-nocookie.com/embed/OOK5xkFijPc :D
- deleted 2y ago[deleted]
- simpaticoder 2y agoI 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.)
- deleted 2y ago[deleted]
- hollerith 2y ago>watts/day instead of joules You mean watt days (watts * days).
- ChainOfFools 2y agoI 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.
- hollerith 2y agoI 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.
- mextrezza 2y ago> 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!
- andyjohnson0 2y agoNevertheless the meaning is clear, and it serves to illustrate their point about reduction in cloud cover.
- two_handfuls 2y agoThe meaning is not clear at all. As a reader, what I got is "the writer made such a basic mistake that what they claim cannot be trusted."
- roter 2y agoUnits 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. [0] https://bionumbers.hms.harvard.edu/bionumber.aspx?id=100943 https://bionumbers.hms.harvard.edu/bionumber.aspx?id=100943
- jessekv 2y agoIf you read it like "Earth gets over 170,000 terawatts of solar energy- all day, every day" then it works.
- amazingamazing 2y agoThese 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.
- TheBigSalad 2y agoWe could solve this problem in a few years with technology if we really wanted to.
- amazingamazing 2y agoNot 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.
- shrubby 2y agoNet zero will come. Whether by collapse or by us shaving the wasteful excess. Excess being the leeches who don't pay taxes or follow rules.
- amazingamazing 2y agoThe issue isn’t taxes. The world’s rich (top 25%) pay virtually all the taxes already but contribute to also virtually all the emissions. You are right though, there will be a correction.
- Aerroon 2y agoJust 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.
- jansan 2y agoWhat causes the shinkage of clouds? By writing "we’re stepping on the gas" you seem to imply that somehow humanity is causing this.
- anthropodie 2y agoDo you mean my dog or other animals are responsible for this? Humans are the only species that are capable of modifying the environment.
- itishappy 2y agoNo 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.