We have heard a lot about global warming, the melting icecap, rising sea level etc. Global warming has been popularized by environmentalists and politicians alike. Head of various governments gathered at the Copenhagen Summit in 2009 to discuss ways to mitigate the rising temperature of our planet. There are, however, some parties who refuse to acknowledge the existence of global warming. Global warming, they claim, is a hoax, created by the science community to achieve certain political purposes. The earth, they say, is actually experiencing a reverse effect called
What causes global warming?
Our transportation system, industries, and cow farming release million of tonnes of carbon dioxide, carbon monoxide, methane, etc into the atmosphere every year. These gases have a special characteristic; they absorb and emit radiation within the thermal infrared range.
When the amount of greenhouse gases in our atmosphere increases, they absorb the heat from our sun and trap it within our atmosphere. The heat cannot escape out to space and thus the temperature of earth increases. This is just like the way greenhouse works, and hence its name "greenhouse effect".
This situation is further exacerbated by deforestation; plants need carbon dioxide to undergo photosynthesis to create food. By eliminating the trees, we are eliminating the carbon sink of Mother Nature.
Although our oceans are absorbing carbon dioxide too, but recent discoveries suggest that our oceans are becoming too acidic and had lost their appetite for the gas~
So why global cooling?
On the surface of the sun, there is this thing called "sunspot", a dark patch on photosphere with lower temperature compared to its surrounding. Sunspots are caused by the intense magnetic field of the sun, causing the inability of the core to convect energy efficiently to the photosphere, and thus creating sunspots. Sunspots have lower temperature, typically around 3000K, compared to its surrounding, which could reach 6000K.
Sunspots would lead to solar flare and solar wind. These are charged particles flung out from the surface of the sun due to the magnetic field. In the movie 2012, the solar wind is the reason why our earth got "cooked" from the inside and thus triggering the Yellowstone Volcano, but it's a hoax anyway, just a movie.
The number of sunspots varies in a 11-year cycle, and the number gathers to produce a graph called the Butterfly Diagram.
We can see that for the year 2010, the number of sunspots hits minimum. Since the number of sunspot is directly proportional to the average temperature of the earth, hence we can conclude that the sun is emitting less heat at earth. Bingo!
This is the reason why there are scientists suggesting global cooling instead of global warming.
But wait a minute.
The sun is not the main culprit of global warming. Global warming is due to the increment of greenhouse gases in our atmosphere that causes the heat from the sun, although not as much, cannot escape out to space. It has not much to do with sunspot minimum or maximum. Of course it is one of the contributing factor but even with lower sunspot activity, the heat from the sun still accumulates in our atmosphere and causing the temperature to rise.
So global warming is true after all.
Again! More amazing discoveries!
National geographic reported that the ice in Antarctica is growing in size(we have heard of the opposite; the melting of icecap, I guess not many of us know about the ice growing in Antarctica).
Why is that possible, especially with our temperature rising annually? Are they not supposed to melt under higher temperature? Why are they growing in size? Something wrong with the ice?
Well, it is yet another effect of global warming, and El Nino.
El Nino is a quasi-periodic climate pattern that occurs across the tropical Pacific Ocean on average every five years, which causes the warming of the ocean. It is a natural phenomenon.
Flooding due to El Nino
When the temperature rises, water vapor accumulates in our atmosphere. And some of the vapor fall as rain, while some are blown to the pole and fall as snow.. as simple as that. Bingo!
It is, however, imperative to understand that the rate of ice growth will never surpass that of rising temperature. Eventually the rising temperature will catch up with the rate of ice growth and cause the ice to melt, this time in greater amount!
So.. global warming is not a hoax. It is true. China is the largest contributor of greenhouse gases, with 6.2 billion metric tonnes of greenhouse gases released in 2006 alone. US, in second place, has put shame to Herself by releasing 5.8 billion tonnes of greenhouse gases in the same year.
We all know the threat poses by global warming. Lowland would complete submerge in water, places like Venice would be completely wiped off the map.
We are encouraged to reduce, reuse and recycle. Is it really that hard to lend Mother Nature a hand when she's having fever? I guess not. =)