Scientists have spent many years in order to find out the cause of global warming. They have observed natural events and cycles known to affect climate. But the amount of warming cannot be explained only by these factors. So, they came to the conclusion that the main cause of global warming is the effect of the greenhouse gases released by humans. There are three main greenhouse gases (GHGs): carbon dioxide (or CO2), methane released from landfills and agriculture, and CFCs (gases used in old refrigerators banned nowadays). When CO2 together with the other heat-trapping emissions get into the air, they cause heat being held in the atmosphere thus warming the planet.
The main points of human activity that cause global warming are: 1) the burning of fossil fuels to drive cars and to produce electricity, and 2) tropical deforestation. When fossil fuels or forests are burned, they release enormous amounts of carbon into the atmosphere. Moreover if there is no forest (point 2), there is no absorption of CO2 from the air.
Global warming results in severe climate change with extremely hot summers and severe cold winters, extreme storms, severe droughts, rising sea levels and acidic oceans which can influence the sources of food and water.
What can we do to lessen the effects of global warming? I think that we should start from ourselves. The smallest thing we can do is to plant a tree. If every person plants a tree, there will be a small forest. We are to consume less electricity and to use green products. As for the country level, I would suggest that our government give more attention to people who invent environmentally-friendly devices such as electric cars, sun energy consuming facilities or equipment for producing sustainable energy. If I were the senator, I would lower (or even ban) taxes for those who start to produce such kind of equipment.