What if Earth's core get cold?

The other day, i was searching through and browsing topics related to my recently asked questions popping up in my mind, one of those question is, "what possibly is the role of molten core of earth has on maintaining our planet stability?" Why did i get curious about that though? Good question, because the other day i was looking for content material on the topic of Planetary Habitability Factors and turns out earth's core indeed play a huge role for life!

So before we get into the answer for the title, we have to at least understand the earth structure first. Here we go... Introduction

Source : https://edu.rsc.org

Uhh.. i hope this is not too complicated to look at, chill..won't go deep wasting time explaining each of the sub-layers of earth but yeah at least say hello to them.

so let's start with Crust...

Crust is the outermost layer, there are two parts of earth crust, first is oceanic which made of magma eruption on seafloor and continental crust which is made from igneous, metamorphic, sedimentary rocks. Crust is important because it is a zone where dry & hot rock from the deep Earth reacts with the water and oxygen of the surface, making new kinds of minerals and rocks which are essential for life habitats

Next is mantle

Mantle made of hot solid rock, Scientists know that the mantle is really...really hot because of the heat flowing outward from it plays an important role in the evolution of the crust and provides the thermal and mechanical driving forces for plate tectonics.

Earth Core

The inner core is solid, the outer core is liquid. Earth’s inner core is solid because the pressure prevents it from melting. The outer core is liquid because the pressure is lower there. It plays a crucial role in outer core liquid motions and the geodynamo, which generates the Earth's magnetic field.

Magnetic field is indeed crucial for our survivability because it protects us from solar radiation. Now.. how is the mechanism of geo-dynamo i was talking about?

So basically, inside the earth core there are flowing stream of liquid metal in the outer core and inner core moving at different speed eventually generates electric currents. These electric current along with earth rotation on its axis causes these electric currents to form a magnetic field which extends around the planet.

Image Source : BBC.com

Now it's time to answer the question hehe..

So yes..earth core is cooling down overtime so one day earth core is going to be completely cool and become solid

The slow cooling of our planet causes the molten iron in the outer core to flow and swirl fast as heat is transported to the mantle, and this gives Earth its magnetic field. The magnetic field is like a magnet that acts at a distance, so let's say if earth core cool down instantly..

first, Earth will lose its atmosphere

Earth magnetic field has been protecting our planet from intense solar radiation so the amount of radiation going in is under safe dose, however without the existence of magnetic field then.. solar radiation will immediately wipe out earth atmosphere causing earth to evolve like Mars, it would be a global climate catasthrope

second, No Tectonic plate movement,

No Volcanoes spewing lava & No Earthquakes..yaaay? no...in simpler explaination it means no nutrition on earth soil, no mountain formed and slowly mountain will erode without being renewed, and overall no lava or deep earth materials means no more minerals and rock forming which is bad for agriculture, farming, and stuff..

third, Earth will be dark place & Ocean will boil although may not fully due to remaining atmospheric pressure

it will become dark place because there will be no geothermal energy needed to produce electricity so yes earth will be darker place. Ocean water will boil because liquid pressure exceed the external atmospheric pressure so there will be a lot of water vapor.

the rest of remaining water will freeze so apparently earth will be left with thick layer of ice.

Fourth, air pressure drops and earth will be more quiet place

yes.. atmosphere is what keep the air pressure as ideal as current condition, just like planet Mercury that almost has no atmosphere at all, air pressure? The pressure of Mercury's atmosphere was determined to be about 10^−12 bar (compared to the 1 bar atmospheric pressure at sea level on Earth). At that level of pressure and atmospheric particle density sound will have less medium to travel so... yeah it will be more quiet place.

Fifth, No greenhouse effect

Where's the greenhouse dome when radiation wipes out the atmosphere? none.. it's gone, so since there is no greenhouse effect the heat emitted by the Earth would simply pass outwards from the Earth's surface into space and the Earth be freezing icy ball brrrr.. just like Mars. Plus without green house gases it is not sustainable for life to continue thriving, plants requires CO2 to do photosynthesize. Nitrous oxide provides plants & animals with nutrients.