Can Carbon Cycle Save Us from Climate Change???

I was preparing for Atmospheric Chemistry’s exam when this question popped up in my mind. So, first of all, I hope you all know about our beloved Carbon Cycle. You should also know that carbon dioxide is a major greenhouse gas and recently its concentration in atmosphere has increased to 400ppm mainly due to human activities.

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So, now comes the question how carbon cycle acts as a thermostat for our Earth? It does so mainly by positive and negative feedback mechanisms. In positive feedback, the processes that are occurring in nature are enhanced (for example, upon increase in temperature these mechanisms support warming), while in negative feedback mechanisms, the processes are opposed (for example, upon increase in temperature these mechanisms support cooling). Maybe this figure will explain them better than I can!!

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Here Albedo means the reflectance of radiations from ice surfaces, thus decreased albedo means high absorbance of radiation. 

 

Now let’s observe how climate change affects carbon cycle and its feedback mechanisms.

  1. Terrestrial Environment 

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In some areas where temperature increases due to climate change, there will be an increase in respiration by plants and this will reduce carbon storage in plants, releasing more carbon dioxide to the atmosphere (positive feedback). Though, in other areas where decrease in temperature occurs, the period of photosynthesis will increase as respiration will be slow, thus carbon will be stored from atmosphere (negative feedback). More carbon dioxide concentrations also support higher rate of photosynthesis.

Similarly, soil stores more carbon at colder temperature and high precipitation as rate of decomposition is reduced. 

This table clearly represents how various factors effect feedback mechanisms.

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2. Ocean Feedbacks
CO2 is far more soluble in colder water than in warmer water, thus warmer sea surface temperatures will affect the oceans’ ability to dissolve CO2 and their carbon chemistry. A warmer ocean might cause dissolved organic carbon to decompose faster and convert to CO2, reducing the amount of atmospheric CO2 that can be absorbed by the oceans (a positive feedback). Warming might also cause a decrease in the extent of sea ice, which could increase plankton and other marine growth in high-latitude regions. This would result in a greater uptake of atmospheric CO2, thereby acting as a negative feedback (Read more here).

Evidence exists that the relationship between climate change and carbon cycle will be very important in the future for determining emissions and carbon dioxide concentrations in the atmosphere.

Increasing Efficiency of Solar Cells by Mimicking Cabbage White Butterflies

A team of researchers from the University of Exeter has shown that the efficiency of solar panels can be increased by nearly 50% by mimicking the v-shaped posture adopted by Cabbage White butterflies to heat up their flight muscles before take off.

08-sn-univ-butterflies-fig1                              butterfly-technique

The angle at which these butterflies hold their wing is approximately 17 degrees. This is the reason due to which these butterflies take flight before other butterflies on cloudy days.

The research team analyzed and tried to replicate the butterfly wing structure to create a new lightweight reflective material with the capability to produce solar energy. The process produces not only lighter, but also more efficient panels.

 

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Ever Used This Device?

I hope you did use it at some point of your lives. This pulse oximeter measures the oxygen level in blood and also records heart rate. It’s so amazing and thought provoking that such a small device can do such wonders. Let’s see how it does so!

pulse-oximeter

So, the basic principle of pulse oximetry is based on the red and infrared light absorption characteristics of oxygenated and deoxygenated hemoglobin. Oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through. Deoxygenated hemoglobin absorbs more red light and allows more infrared light to pass through. Pulse oximeter uses a light emitter with red and infrared LEDs that shines through a reasonably translucent site with good blood flow.

figure-1-dr-petty-brochure An emitter and photo detector are involved in the transmission and receiving of these LEDs. After the transmitted red (R) and infrared (IR) lights pass through the measuring site and are received at the photodetector, the R/IR ratio is calculated. For example,

  1. a R/IR ratio of 0.5 equates to approximately 100% SpO2,
  2. a ratio of 1.0 to approximately 82% SpO2,
  3.  and a ratio of 2.0 equates to 0% SpO2.

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References and further reading

http://www.oximetry.org/pulseox/principles.htm

http://www.nonin.com/How-Does-a-Pulse-Oximeter-Work

How pulse oximeters work explained simply.

 

Test: How Well Do You Know Your Environment?

Hi. I am thinking about starting a daily quiz on environment. I hope you enjoy it and that it helps us know more about our environment! Please answer my question by typing in the correct option in the comments section. The winner’s name will be shared in the next quiz along with the correct option.

Which element causes the minamata disease?

a) Arsenic

b) Mercury

c) Cadmium

d) Uranium

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