The Earth average temperature today is clearly warmer then it was a century ago. The earth itself will naturally warm up slowly that is how the earth has gotten out of all of the ice ages. Many Scientist strongly agree that increasing quantity of human greenhouse gases (like the gas that comes from cars) is causing the rate of the warming to increase. This is cleary being shown over the last few years the surface temperature of the oceans have gained from 1.8 to 3.6 degrees. This may not sound like much but as the surface temperature rises the strength of our hurricanes will surely gain force. According the the Massechusettes instituted of Technology the Atlantic and Pacific storms have increased in intesity about 50% since 1970.
Global warming causes more than just the temperature to be a few more degrees warmer in the summer. No the effects will be much more severe. One of the most hazardose Would be the rising sea level. The sea will rise up to one whole foot. May not sound like a lot but the effect on the areas close to the sea (The swamps and marshes) will be flooded even more ruining a habitat thus killing hundred of secies. Also the in the artic glaciers are shrinking more rapidly then before. Again killing more species of animals. Like the polar bear whose entire life depends on stable ice so they can walk on to reach the fising spots these animals will not be able to adapt fast enough and already they are fading.
What can you do to help. Well what you hear on T.V. is mostly true. Changing the smallest thing in your life can make a big difference. Like changing a light bulb from a normal to a energy efficient one. Driving less will greatly lower the number of emmissions let out. Also walking is healthy for you and the enviorment.