Global warming is caused by several causes such as pollution from factories, carbon dioxide from rotting trees, the burning of coal, natural gasses and fossil fuels lead to methane travelling into the Earth's atmosphere any transportation vehicles, water vapour, and many other little things, which contribute to make global warming even worse. Scientists have different opinions about whether the current global warming is natural or unusual. Some believe that it is part of the Eath's natural cycle of warming and cooling.
However most believe that what we are now experiencing is unusual and has been caused by human activities. Another great contributor to Global Warming is water Vapour. You may be thinking how does water vapour contribute to Global Warming, well the answer is water vapour does not directly contribute to Global Warming. It contributes to the Greenhouse Effect, which then leads to Global Warming.
In fact, water vapour makes up sixty percent of the Greenhouse gasses, twenty percent is carbon dioxide and the other twenty percent is caused by nitrous oxide , methane , ozone and other varieties of gasses.
How is Global Warming caused?
Save My Sweet Polar Bear
Human activity threatens the extinction of species at three levels. The first, and most direct, is hunting. Then there is direct habitat destruction by farming or construction. And finally there is the indirect threat from habitat loss caused by climate change, which in turn is mostly caused by humans. Of these, it is the last that is easily the most important. Polar bears have been hunted since the arrival of hunter-gatherer Homo sapiens; they have been part of the Inuit economy for as long as that society existed admittedly a small part and mostly without high-powered rifles.
Western urban dislike of hunting should not distract us from the big issue but it can be mobilised to guide people to it. Earlier this year, we reported that Zac Goldsmith, David Cameron's environment adviser, complained that it was easy to raise money to "save" particular animals, whales, pandas and now polar bears but difficult to raise money to "campaign for increasing the fuel efficiency of cars to combat global warming... even though polar bears will not survive climate change".
That is plainly true, but he was wrong to imply that the "soft, feel good things" somehow got in the way of the "grittier stuff". If people care about the fate of polar bears then it is not difficult to persuade them that the real threat to their survival does not come from hunters but from global warming gases produced by humanity's energy hungry prosperity.
Nor is it hard to convert anger at the bloodlust of power sled tourists into a more reasoned critique of the irresponsibility of shooting animals as their habitat melts beneath them. Indeed, the ratchet effect of emotive symbolism is already working. Polar bears are likely to be listed in January as a "threatened" species under the US Endangered Species Act, based on a scientific assessment of the impact of global warming.
Unfortunately, this ratchet effect is working too slowly. Yesterday, for example, the US and Australia both countries previously in the front ranks of climate change scepticism signed a declaration by the Asia Pacific Economic Co operation forum. It did not even promise to "consider", as the G8 richest nations did, the target of halving global emissions by 2050.
Sun remained quite for about 70 years
Our Sun has observed cycle of rising and falling magnetic activity. But as cycles in nature teach us time and time again, you usually can’t set your watch or your calendar by them. The Sun is a huge ball of hot, electrically charged gas (plasma mostly hydrogen and helium ions and electrons). Its constant internal motions of plasma the rising and falling of convection cells, the non-uniform rotation of the Sun that involves a lot of twisting and sheering generate magnetic fields, as any kid who has built an electromagnet might guess. In an electromagnetic, an electric current (moving electrons) generates the magnetic field.
The Sun magnetic fields can grow quite strong in areas, generated beneath the Sun visible surface (photosphere) and rising up through that surface and into the Sun enveloping atmosphere. At the photosphere, the magnetic fields tend to suppress the rising convection of plasma, choking the flow of heat from the interior to the surface and making spots that are less hot than the general surface (4000 degrees as opposed to 6000 degrees). The cooler spots are less bright, and we call them sunspots.
The same magnetic fields that leave their mark on the photosphere as sunspots rise into the solar atmosphere, where their sometimes violent twisting and interaction heats the gases there, and can power violent explosions such as solar flares and coronal mass ejections, both of which can affect the Earth.
So, sunspots are a visible sign of magnetic activity, and over the last 400 years of regular observations and counts of sunspots, a distinct 11 year cycle from one peak of activity to the next has been identified. Between peaks of activity (called solar maxima) are periods of relative "quiet," magnetically speaking, when there are few if any sunspots observed, and events like solar flares and such are not common.
We are currently in the midst of a solar minimum the last solar maximum that occurred was around 2000/2001. But what has scientists buzzing right now is just how "deep" a sleep the Sun seems to be in. 2008 was the quietest year for the Sun on record since the beginning of the space age. Out of the 366 days last year, on 266 of them the Sun was completely spotless, which is well below "normal" for a solar minimum year.
What does it mean? Well that is difficult to say right now. Scientists are still trying to understand why the Sun experiences its 11 year cycle at all. And it’s not unprecedented, the Sun has experienced "deep minima" before. In 1913 there were 311 spotless days. Other deep minima have been seen in the sunspot record, and in almost every case normal solar activity returned, the next solar maximum is expected to peak in 2011 or 2012 maybe 2013
