This is a graph about the increase in global temperature for the past 100+ years. As seen the temperature has been rising and it is quite significant. This has been due to industrialisation and the rapid development in many countries. During the Industrial revolution,much labour was replaced by machines. To power them, much coal was burnt which resulted in the emission of green house gases. Green house gases are those that trap heat in earth, thus also resulting in global warming. Now, as urbanisation is very common, most cities in the world have high energy consumption and so burn many fuels, which also result in CO2 emission. Now, let us look at the amount of Co2 emission values of over the years.

As seen, the amount of atmospheric CO2 has been increasing steadily, with no dip or whatsoever. This supports the reasons that were given.

So, you ask what's so scary/bad about global warming? The first most obvious prediction would be that the ice caps at the two poles will melt faster. Thus there would be a rise in sea level. It will then flood many cities that are low-lying. It could also interupt the water system and change the climate, making some places rain heavier and making other places even drier. Agricultural products will be adversely affected and much money will be lost. The values estimated run from US$-10 per tonne of carbon (tC) (US$-3 per tonne of carbon dioxide) up to US$350/tC (US$95 per tonne of carbon dioxide), with a mean of US$43 per tonne of carbon (US$12 per tonne of carbon dioxide).To prevent this, many countries have agreed to cut down on their CO2 emission through the Kyoto Protocol. However, I feel that countries like China And Inda should not be exempted from it. They are the major emittors of CO2 and thus it is also their responsiblity to reduce CO2 emissions. It is only through the efforts of everyone that we can reduce the effect of global warming. As such, i would also like emphasize on individual efforts to reduce their consuption of energy and do a part for our earth. Save the world,save us.

-Zijun Source:wikipedia