Jornal2

What’s your idea about the most important key word for 21st century? Global warming may be the first choice for most of people. Yes, we heard about this phrase day by day, from the serious text-books to the household electrical appliances advertisement. Our minds are filled with words like greenhouse gases and carbon footpath. But what is our attitude towards to the phenomenon which can totally change our life style or even the future of human beings? Unfortunately, we don’t care about it. In most people’s mind the global warming is nothing to do with their daily life. They pay for it, consume it, and forget about it. But I want to say, we can do much more just by saving a little electricity and gas.
We can easily save a lot of electricity and reduce the global warming effect by just adjusting the setting of the air-conditioner. The first reaction when I walked into the airport is, wow, it is so cold there. I am wondering that if it is necessary for people to create another winter indoor when we have already had one outdoor. In my opinion, the purpose of air conditioner is to create a comfortable environment for people but not a cold one. How to define the word comfortable? A study recommends room temperature should be at a maximum of 77.0°F (25.0°C) 1. But the fact is almost every air conditioner in the public are set at 65°F or even low temperature. In this kind of situation the air conditioner is creating a bad weather for us instead of a comfort one. The result of it is the energy consuming, which has directly related to the carbon dioxide releasing. As we know, we can save 4%-6% of energy by just make the temperature 1°C higher 2. It means, we can both save the energy and reduce the greenhouse gas and live in a better condition, why don’t do that?
Another way to save the earth is decrease the number of big cars like mini-van or SUV. A big difference between Europe and America is that people in Europe always drive small cars (2 seats, 1.0L engine) but people in America prefer the big cars. But in most cases there is only one passenger, the driver, in these cars whose capacity are 4 people or more. We need much more gas to start the car itself rather than carry people. I know that big cars are convenience when people need to make a move but considering the gas we lost in the daily life, it may be cheaper to contact a moving company. Most people need drive everyday but few people need make a move frequently.
All in all, we can do much than we thought. To save earth equals to save ourselves, why start now?


1/Dan Norbäck (1995) Subjective Indoor Air Quality in Schools - The Influence of High Room Temperature, Carpeting, Fleecy Wall Materials and Volatile Organic Compounds (VOC) Indoor Air 5(4), 237-246.

2/《工程热力学》清华大学出版社 (It is my textbook in thermodynamics)