Author Archives: Jenny Tang

Will electric cars fully replace combustion engine cars in the future?

Vehicle emission is one of the largest contributions to air pollution in the world. In order to reduce exhausts, people can choose to drive electric cars. Although electric cars seem to be more environmentally friendly, in my view, petrol and diesel-fueled cars cannot be completely replaced in the future because of their convenience and efficiency.

Electric cars vs. diesel-fueled cars; Photo courtesy by Chris Tosic

In terms of fuel efficiency, fuel-filling cars are more efficient than electric cars. Due to the limited capacity of batteries, fully charged electric cars normally cannot drive as far as fully fueled petrol and diesel cars. The usual battery life for today’s electric cars is about 100 to 150 kilometers. However, a fully fueled car with combustion engine can travel at least 400 to 500 kilometers normally. Although today’s most popular electric car brand “Tesla” has developed more powerful batteries for their electric cars to allow the driving distance to increase up to 572 kilometers, the price of the car with higher electric capacity becomes so high that it can be economically inefficient.
Apart from driving distance, the way of getting energy is another big concern for electric cars. In today’s community, we can find a lot more fuel-filling stations than electric charging stations in cities. Here is an example for the United States:

NO. of US Gas Stations VS. Electric Charging Stations; Data table provided by Loren McDonald

Moreover, the fuel charging only takes a few seconds or minutes to complete. In this case, we do not need to worry if the car does not have much fuel left. Conversely, electric cars take a much longer time to charge, and we do not have many electric charging stations in the city at present. For example, the total time required for a Tesla “90kWh Model S” electric car to be fully charged at a 30A public charging station is about 17.8 hours; even “Tesla Supercharger Station,” which is recognized as worlds’ fastest charging station, still takes 75 minutes to recharge an electric car. As we know, the higher capacity battery takes longer charging time. Therefore, petrol and diesel-fueled cars save much more time on fueling and cannot be completely replaced by the inconvenient electric cars.

In the future, people may develop more advanced electric cars that require shorter charging time and have longer battery life. It is important to note that recycling of large batteries may also become a significant environmental issue. Consequently, there are still many challenges in the development of advanced electric cars.
By Jenny Tang

Save the plastic = Save the life


This video is from National Geographic “How the global ocean plastic pollution problem has become ubiquitous”.

Recently, a catastrophic news “Plastic Garbage Patch Bigger Than Mexico Found in Pacific” published last year has caught public attention. It reported a new finding of a huge region of plastic pollution in South Pacific (near the coastal region of Chile and Peru).

The plastic pollution in the ocean not only means floating bottles or buoys which can be easily discovered but also includes the small pieces of plastic debris which may be invisible. So the ocean cleanup is very difficult. Based on the historical data in 2012, the mean abundance of plastic pollution in South Pacific was roughly 71 kg/km2. What a shocking number it is! The extreme increase of the plastic pollution in South Pacific over the last six years has threatened many marine species and seabirds.

The plastic garbage “patch” includes both big piece (macro-plastics) and very small piece (micro-plastics). In a short-term effect, those seabirds and marine species who accidentally ingested or consumed plastics will stick in their tissues forever (just like the image below). The previous research has shown that mussels ingested micro-plastics through gills would transport to the stomach and digestive glands. In biology classes, we learned that toxins will be accumulated through the food chain and magnified in carnivorous species. As a result, more species will be harmed. Eventually, the whole ecosystem may be negatively impacted.

Plastic debris was found in seabird’s stomach; Photo courtesy by Chris Jordan

Right now, the first aid is to clean up the plastic waste in the ocean. This is because the residence time of plastics in the ocean is very long. Also, its degradation time under UV light and water is still uncertain. After breaking into small pieces, micro-plastics will further sink down to the ocean and release toxic chemicals. Although it is a difficult work to clean up all the plastics in the ocean, we still need to try our best to solve the existing garbage. Thus we can prevent further contamination of the marine environment.

Moreover, it is important to increase public awareness of the garbage dumping near coasts. Since most of the containments are anthropogenic, if the general public can get better understandings of the harmfulness of certain behavior, the marine ecosystem will be more sustainable.

In the future studies, scientists should focus more on the problem solving of the ocean plastic pollution, especially appropriate garbage disposal and recycling. Also, an alternative material to plastics that is nontoxic and easily degraded is encouraged to be investigated.

By Jenny Tang