I was walking across the campus last week. The temperature was -9 when I overheard someone say “It’s so cold today! So much for global warming.” This was not the first time that I have heard this statement either; it made me feel obligated to educate my fellow Western students about the topic of global warming as many do not seem to fully understand it.
First and foremost, what is global warming? And what are its main causes? Global warming is the observed century-scale rise in the average temperature of Earth’s climate system. It is caused by the human expansion of the “greenhouse effect”– warming that results when the atmosphere traps heat radiating from Earth towards space. Certain gases in the atmosphere block heat from escaping. This green house effect is cause by the release of green house gases by human activity of energy consumption. The gases form a layer that acts like a blanket around the earth.
So this raises the question: if increased energy consumption is causing the global climate to increase its temperature, how is it that winters are getting colder? To find the answer to this question, you have to look at the big picture. Even though the last couple of winters were really cold, the overall longterm temperature is increasing. I like to use this analogy: “if you are cold it doesn’t mean that global warming doesn’t exist, just like if you are full it doesn’t mean that world hunger doesn’t exist.” Humans brains are well adapted to deal with clear and present dangers, but they are not so good at handling complex long term probabilistic forecasts like temperature change.
This trend can be seen from the graph below. According to the scientist’s at NASA’s Goddard Institute for Space studies, since 1880, the global warming temperature change has increased – and the planet’s has warmed by 0.8 degrees C (1.4 degrees F). This might not seem to be a large increase but remember that this is the global climate that we are talking about. It doesn’t take a lot to change the temperature of a city by some degrees but when we are talking about a whole planet, then it’s a big deal!
So what might happen if the earth get too hot? There are many consequences of increasing the global temperature:
- Extreme weather, making hot days hotter, rainfall and flooding heavier, hurricanes stronger and droughts more severe.
- Rising sea levels due to thermal expansion of water in oceans.
- Extinction of species. Some polar bears are drowning because they have to swim longer distances to reach ice floes, decreasing their population further.
- Water scarcity. If the ice caps and glaciers continue to melt at the same rate, there will not be any fresh water available in the future.
This post was inspired by a Youtube video that would perhaps explain the situation further. Click here to watch the video .