My Science School

There's a good reason our planet is called "the water planet- nearly two-thirds of it is covered in water. To quantify it further, that's more than 300 million cubic miles of water. That's quite adequate for humans, isn't it? Well, not really. Because, 97% of it is in the oceans - salty, undrinkable and not usable for cooking or raising crops. Oh, so we have just 3%? Well, not even that much. Because about 2.5% of that is trapped in glaciers, ice caps, the atmosphere, and soil or is inaccessible because it lies very deep under the Earth's surface. So that leaves us - over seven billion humans (and wildlife!) - with less than 0.5%. Do you know how little that is? A report says that if all the water in the world can be equated to 100 litres, then all the freshwater we have access to is about half-a-teaspoon! Our drinking and cooking water sources are groundwater, freshwater lakes, rivers, etc Though water can be seen as a renewable resource, the demand for freshwater has been slowly outdoing how much is replenished naturally, especially through the likes of rain. This is indicative not just of imbalance and a changing planet but also of potential global health and political crisis. That wars could be fought over water may not be a problem of a distant future. Which is why there has been consistent and loud calls for water conservation and recycling universally. The impact of water shortage has been showing, and when the problem becomes even more acute it will affect not just humans but also the plants and animals in it and most importantly, our planet itself as a whole.

 

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The history of our planet has been divided into tiny sections of time, and this is called geologic time. Depending on many factors within a specific period, these sections are called eons, eras, periods, epochs, and age. What we now live in is officially called the Holocene (meaning “entirely recent”), an epoch that began more than 11,000 years ago after the last major Ice Age. However, for decades now, many scientists have been calling for a specific name to be given to the epoch that begins mid-20th Century. A name that will sum up how intensely and singularly we humans have altered our planet – Anthropocene (anthropo meaning “human” and cene, “new”). Mid-century was chosen because that’s when the first atomic bomb exploaded leaving behind radioactive debris in sediments and glacial ice, “becoming part of the geologic record”. While we do not know if Anthropocene will be officially accepted and adopted, what we can be sure of is that our actions are directly responsible for how the Earth is today. In fact, we’re in the midst of the sixth mass extinction – the first one for which humans are to blame! But many are still hopeful that we can work collectively to save the planet despite the window of opportunity closing really fast.

 

Picture Credit : Google

Our planet did not always have seven continents.  surprised? Our universe began with the Big Bang about 14 billion years ago, and Earth was formed about 4.5 billion years ago. During its history. Earth has witnessed the coming together and the breaking up of its land masses several times, A single large land mass is called a supercontinent. There have been many supercontinents so far. The youngest supercontinent is Pangaea, formed more than 300 million years ago. This is said to have been formed when two land masses Euramerica and Gondwana - collided. Pangaea began to break up nearly 175 million years ago, and gradually fomed the world as we know it today - Gondwana became Africa, South America, Antarctica, India and Australia, and North America split from Europe. This tremendous geographical alteration also means great impact on the environment climate and biodiversity. For instance, the collision of land masses results in the creation of large mountain chains, which directly impact the dimate in the region. Also, when only one large land mass exists, the most interior regions are far removed from oceans and experience dry weather. However, when the land mass breaks up, many regions earlier in the central part get surrounded by water, altering weather patterns over a period of time. Studies also show that broken-up continents "create more ecological niches and promote favorable dimate and environmental conditions that are conducive to biodiversity" A study said that "marine species tend to become more numerous when the continents divide", and come down in great numbers when continents come together - a small example of a supercontinent's direct impact on biodiversity.

 

Picture Credit : Google

Take a moment to look around and you will realise plastic is truly a ubiquitous material. It is difficult to imagine life without plastic Plastic production has increased exponentially over the years from 48 million tonnes in 1970 to 448 million tonnes in 2015.

Plastic materials not only remain in the landfills for years, leaching out chemicals into the environment, but also affect marine life when they end up in the ocean. Thankfully, people are slowly waking up to the dangers plastic poses to life and the environment. Globally, consumers and manufacturers are scrambling to find alternatives to plastic. One of the promising finds turns out to be bioplastic.

What's bioplastic?

Bioplastic simply refers to plastic made from plant or other biological materials. (Conventional plastic is derived from petroleum, a fossil fuel.) There are two main types of bioplastics. While PLA (polyactic acid) is typically made from the sugar in com starch, cassava or sugarcane, PHA (polyhydroxyalkanoate) is biosynthesised by microorganisms. The former is commonly used in food packaging and making utensils, the latter is used in medical devices such as surgical sutures and cardiovascular patches.

Advantages

While petroleum-based plastics are generally not biodegradable. bioplastics are biodegradable and compostable under the right conditions.

Bioplastics are made from renewable resources, thus limiting the use of fossil fuels.

However…

There are some environmental issues associated with bioplastic

• Research has found that bioplastic production can result in pollution due to the fertilizers and pesticides used in growing the source crop. • Plant-based bioplastic production also requires extensive land which could otherwise be used for food production.


• Production of some plastics leads to emission of cancer causing toxins into the air.


• Bioplastics often end up in landfills where they may release methane, a greenhouse gas more potent than carbon dioxide, during degradation


• In most cases, bioplastics will break down only in a high-temperature industrial composting facility and very few cities have the infrastructure needed to deal with them. In case of bioplastic not being treated, it is as bad as conventional plastic.


• If bioplastics end up in marine environments, they will last for decades, posing a danger to marine life.

Scientists are working towards finding a way to address the above issues.

 

Picture Credit : Google