Warmer water temperatures caused by climate changes alter coral reefs areas by stimulating coral bleaching due to their sensitivity to changes in temperature. Coral reefs without zooxanthellae, turn white, since this is what gives corals their appealing color, and makes them weak. 

Round 2: What if.... the energy gradient change? 

 Less reading, yet key terms are not as easy and cute as it appears to be.
Only 5 minutes but let's see how many times you have to review :)

Oceanic circulation: Thermohaline circulation and Wind-driven circulation

What do we need to know about thermohaline circulation?
Thermohaline circulation is how ocean water move around the world by density gradient. This mechanism is influenced by temperature and salinity (salt content).

What is salinity? How salinity is different among the sea? How this impact climate change?

Don't worry, Cute Furball is coming to rescue!

Consider this experiment 
There is a frozen salt water in the fridge. After 20 minutes, the ice cold start to melt a little bit. You pull a small portion into a small cup (A). After 1 hour, all the ice has melt down, you pull another portion into another cup (B). Cup A is more salty than cup B.
Why? Because in cup A has less water but more salt (the water still store in the ice). While in cup B, the ice have all melt down, leaving the cup with more water and salt.
Cup A: is represent the water in the Poles (cold and salty)
Cup B: represent water at the equator (warm and more mixed with molecules)

Remember what we learn from Chemistry?
Cold and salty-->higher density--> Sink
Warm and less salty-->lower density-->Rise.
This is how thermohaline circulation work.

Thermohaline circulation is important to climate change because it is the absorption mechanism that controls the amount of carbon dioxide in the ocean. The more carbon dioxide absorb into the ocean, the warmer the sea temperature. Increasing temperature is not the only changes that global warming bring to the ocean floor, but it is also the increasing ocean acidification which we will further discuss in the next section.

 

Got it? Ready for round 2? The global warming and changes in thermohaline circulation?

Question: Why does the global warming in the atmosphere have to to with changing temperature in the ocean?

Answer: The atmosphere and the ocean exchange energy simultaneously based on the different in energy, density, and pressure gradient. Any changes in energy gradient in the atmospheric circulation would eventually reflects on oceanic circulation as well. 

Question: What is climate feedback?

Answer: Feedback is things that respond to temperature change (and also affect temperature as well). The picture illustrates positive feedback of oceanic temperature which influence by changing atmospheric temperature.

As more CO2 is put into the atmosphere, more CO2 is then absorbed into the ocean.

The amount of CO2 that is coming into the ocean is greater than the amount of CO2 that is leaving it, as well as the amount that plant life in the ocean can absorb from it.  This leads to the ocean becoming more and more acidic over time.

The absorbed CO2 travels in ocean currents that travel on the surface and deep in the ocean as a result of the ocean's thermohaline circulation.

As the CO2 travels along the surface currents the acidity of the CO2 infused ocean water can effect the development of sea life.

This increased amount of CO2 has a particularly harmful effect on coral reef growth and health, as well as the health of all the marine life that lives in the coral reefs themselves.

The increased CO2 emissions that we have created over time will have a dramatic effect on all ocean life, but especially coral reefs which are very sensitive to even the smallest change in the chemical makeup of the ocean.

If these effects on the ocean continue, there may not be any coral reefs in the future to speak of.