What will happen to the earth if it slowly decelerates it’s rotation over the course of, let’s say a 30 years?

127 viewsOtherPlanetary Science

I know what exactly will happen if the earth stops rotating all of a sudden – the momentum would cause untold destruction and everything not securely anchored to the ground would be hurled eastward at devastating speeds. I’ve seen a shittona clickbaity videos on YouTube. I also know the final result of this would be 6 months of daytime and 6 months of night. But what would be the other visible effects on earth which would start as soon the deceleration begins? Will we be able to survive?

In: Planetary Science

8 Answers

Anonymous 0 Comments

What effects are you interested in? It would affect everything.

In your scenario is the Earth still rotating at all? Or is it tidally locked to the sun with a permanent dark and light side?

Anonymous 0 Comments

The slowdown itself would be harmless and likely unnoticable. There would be a sideways acceleration about one bilionth the gravitational acceleration.

The disruption of the climate would however be immense. Just turning off the coriolis effect would remove the driver from many ocean currents, resulting in a more stagnant ocean. Meanwhile the easterly and westerly winds are also due to the coriolis effect. They would be replaced with winds blowing from the equator towards the poles largely uninterupted.

Not to worry, because this would be overwritten by the consequences of extremely long days. The poles might remain remotely hospitable, but the rest of Earth would alternate between polar winter and summers unlike anything on Earth today. The massive temperature difference would drive extremely powerful winds between the day and night side, making even the transition unlivable.

Anonymous 0 Comments

Astronomers would notice almost instantly. The rotation of the earth is measured within fractions of a millisecond, and you’re talking about losing several seconds daily.

At the end of day 1, GPS systems are a few hundred metres out, and this gets worse very quickly.

After 1 year, the day is about 25 hours long, making days hotter and nights colder. Our calendar is probably still in use, but is out of sync with the seasons by about 1 week. The weather is unpredictable because meteorological models assume a 24 hour day, though there will have been time to update some

The drift accumulates, and everything is three times worse at the end of year 2. The extreme temperatures start to wreak havoc with agriculture, pushing up food prices. The climate is probably also affected.

Parts of the world become uninhabitable in summer by about year 3 to 5, because the days are just so long and they heat the ground so much. This leads to a massive refugee crisis, but not as massive as the sheer number of deaths – these places include some of the most densely populated areas on earth. Nobody wants to live anywhere near the tropics. The global economy is totally trashed, nobody anywhere has enough food.

Heating of the ocean pumps massive amounts of water into the atmosphere, which leads to megastorms like we’ve never even imagined.

From then on out it just gets steadily worse.

Anonymous 0 Comments

If i did the calculation right, this is lowering the rotational energy by 63%

From today 2.58 x 10^29 Joules down to 1.63 x 10^29 Joules.

That is 9.50 x 10^28 Joule.

A number with 28 digits.

The biggest known atomic bomb the Tsar counts 50 Megatons = 2.092 x 10^17 Joule.

That is 4.541 x 10^11 biggest atomic bombs

41 Million bombs per day

1.7 Million bombs per hour

479 Tsar bombs per second every day 30 years long.

Anonymous 0 Comments

The trade winds probably slow down. Hot places will become much hotter, cold places much colder. The weather pattern changes fairly quickly since the cooling and heating cycles change. Wet places might become much wetter and dry places much drier. Since many river systems depend on snow accumulation and precipitations in higher altitudes, they might fail too. Rivers run dry or with much less water. Many areas will see plant and animals dying off.

Humans might initially cope but probably not very well or for very long. Many areas without water will also see either mass migration or mass human life extinction. If the final outcome is a tidally locked earth to the sun (ie one side facing the sun permanently), then there will only be a very narrow band where temperatures are reasonable – one side being cold and the other super hot. It is unlikely that any humans survive by then unless we start living permanently underground as there might very well be very vicious winds and weather caused by the heating and cooling. We’d certainly need some kind of super structure built to withstand the weather and to possibly maintain the minimal amount of agriculture needed to grow food.

Of course without much plant life, the oxygen and carbon dioxide levels will also dramatically shift meaning whatever artificial environment created would need to be able to manage this as well. And without rotation, the protective magnetic field of the earth is gone – meaning we’d have to make shelter that shields us from cosmic and solar radiations. After a while, even the atmosphere might be stripped from earth due to this radiation. At that point humans are probably gone.

Anonymous 0 Comments

>I’ve seen a shittona clickbaity videos on YouTube.

You know this is actually a not really good source to claim that you know about something right?

Anonymous 0 Comments

Technically, the Earth **is** slowly decelerating. It’s just over much more than 30 years. Each century, a day becomes almost 2ms longer.

Still, if it just decelerates before coming to a stop in 30 years, that’s slow enough to avoid any immediate collapse. It will mess up satellites and various time measurements, but nothing we can’t adapt to. That’s going to break a lot of computer systems for a while, but then we can take the change into account to fix it. So it’s just a messy transition period.

The real problems starts not because it decelerates, but because it becomes too slow. Having very long day and very long night is going to create much large differences in temperature. The nights are colder, the days are warmer. This in turn can lead to more violent winds. The climate get all messed up, far beyond the global warming that we know.

Once you reach about 6 month days and 6 months nights, most of the planet is wasted. Temperatures in the day are going to be hotter than the hottest summer we’ve ever seen, and nights are going to be colder than the coldest winter. We could try living on the small temperate zone in the twilight/dawn area. But that’s also where you should expect the most violent winds. And that area is moving, so we’d have to migrate to always follow it. How are we going to sustain agriculture in such a world?

Some forms of life are probably going to manage to adapt, maybe in the deep sea more than elsewhere. But I don’t think humanity will survive this for long.

Anonymous 0 Comments

Water that will get to the shady side will freeze and never go back to sunny side. Over time all water will end up there