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.
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!!
Now let’s observe how climate change affects carbon cycle and its feedback mechanisms.
- Terrestrial Environment
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.
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.
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.
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.
This specific issue became evident to me when I surfing twitter. Artisanal and small-scale gold mining (ASGM) is the extraction of minerals by miners working in small and medium sized operations, using rudimentary techniques. Simple practices with minimum economic investment are employed be these miners. It is the largest intentional-release source of mercury in the world.
How can mercury be used for gold-mining? Mercury is used to separate and collect the gold from the rocks. Mercury binds with gold to form an amalgam which facilitates it to separate from rock, sand or other material. The amalgam is then heated to vaporize the mercury leaving the gold behind.
Mercury is a powerful neurotoxin that is harmful to people, especially to developing fetuses, and young children. Once emitted, it can travel great distances through the atmosphere, causing global contamination of ecosystems, fish, birds, mammals, and the human food chain.Local exposures in mining communities that use mercury can be acute.
What to do now?
- The most important measure a mining community can take to reduce its mercury use is to concentrate the gold-containing portion of the ore before adding mercury. This can be done by crushing and grinding the ore and then using carpeted or magnetic sluice boxes or gravity concentration techniques such as panning or centrifuges. In this way, more gold will be captured, less mercury will be required and residual mercury can be more completely captured.
- Protective measures include the use of retorts when burning amalgam and the use of gloves by those handling mercury or amalgam.
- Most promising technology to replace the use of mercury is cyanidation, but this method may not be affordable or technically available to all artisanal miners. Also, cyanidation methods must be used with care and carefully introduced due to its significant risks to human health and the environment.
For further info check reference texts http://www.unep.org/hazardoussubstances/Portals/9/Mercury/AwarenessPack/English/UNEP_Mod3_UK_Web.pdf
(For those who don’t like reading science stuff scroll down and have a look at the infographics)
Agroecology is this short answer. It can help us establish sustainable food systems.
Just a few month back I was very surprised and unhappy that we were to be taught this subject. But since I attended this subject’s first class I have been in love with it. So, the first question in your mind would be what is wrong with our current food system. The following infographic will make that clear to you and later on I’ll ramble about it.
The current agriculture is highly dependent on human inputs. This dependence is mainly due to the agricultural practices like monoculture (planting same crop over a larger area), intensive tillage, use of fertilizers, insecticides, pesticides, factory farming, etc. These practices make an ecosystem of their own that is agroecosystem. Agroecosystem cannot sustain itself. In this system, energy and nutrients are lost. It is not resilient to disturbances and change. It has very simplified food chains. Hence, agroecology applies ecological principles to agroecosystems. This can be done by increasing biodiversity thus making food chains complex, agroecosystems stable, reducing dependence on human inputs, etc. Some of these methods have been beautifully described in the following infographic.
The difference between agroecological and conventional agricultural practices can be observed very clearly in this infographic.
Here goes an infographic about how agroecology relates to climate change.
Sources of infographics have been linked.
So, in my last post, I asked you for your suggestions at Need Suggestions Please (about shoes)! about whether or not to buy high boots. If you visit my previous post you’ll understand why I wanted suggestions. Thanks to the suggestion of milae, I was motivated to buy them. I ordered them online (my first online shopping experience) and they look awesome.
So, Alhamdulillah I fulfilled my dream!
P.S: Mehwish you’re right. I have bought them but still don’t know how I am going to wear them!
I wish to buy high boots but the issue is I don’t wear jeans at all. All my clothes have shalwars or trousers. And the length of the shirts are till knees or below.
So, there is a sale that will last till 12 AM today. My budget is limited I want them as cheap as possible. But these shoes are knee high.
How can I wear high boots on shalwar and palazzos????
Another option is to wait for offseason sale on ankle high boots.Please tell me what to do..
She entered her room hastily and closed the door. She couldn’t bear to listen to her parents’ conversation. Only because it conveyed her a message. The message that she was growing up. She couldn’t bear the mere thought of leaving her comfort zone. Her home. How could she go away from a brother who does nothing but love her? Who she loved so much. How could she go away from her sister with whom she shared every laugh, joke, and feeling? How could she get away from her mother who loved her above all else? A father who loved her no matter what. But this was essential. And was going to happen one way or another. It was going to happen someday. And she would have to accept it that day.