I finished making my speech.

Global warming
You’ve heard ‘global warming’ haven’t you?
Do you know the ice of Arctic Ocean will melt in 30 years and disappear?
It is true developed society is very convenient for us, but if we continue to develop, we can’t live near feature. Though most people may have known ‘global warming’, we rely on developed and convenient society. I feel there are some contradictions. Today, I goanna tell you what is global warming and what we can do for earth. After listening, I’m happy if you are interested in global warming.
Global warming refers to the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. The Intergovernmental Panel on Climate Change (IPCC) concludes, “most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations" via the greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward. Climate models referenced by the IPCC project that global surface temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100. The range of values results from the use of differing scenarios of future greenhouse gas emissions as well as models with differing climate sensitivity. Although most studies focus on the period up to 2100, warming and sea level rise are expected to continue for more than a millennium even if greenhouse gas levels are stabilized. This reflects the large heat capacity of the oceans. An increase in global temperatures is expected to cause other changes, including sea level rise, increased intensity of extreme weather events, and changes in the amount and pattern of precipitation. Other effects of global warming include changes in agricultural yields, glacier retreat, species extinctions and increases in the ranges of disease vectors.
There is ongoing political and public debate worldwide regarding what, if any, action should be taken to reduce or reverse future warming or to adapt to its expected consequences. Most national governments have signed and ratified the Kyoto Protocol, aimed at reducing greenhouse gas emissions.
Then, what can we do? We don’t have to think it difficult. The small step is going to be great. I’ll tell you what we can prevent global warming below.
1. Refrain from using air conditioner.
2. Use public vehicles.
3. Take shopping bag with you from home, when you go shopping. Don’t buy things wrapped too much.
4. Don’t take a shower too long.
5. Abstain from using elevators.

If you change and improve your life style, you can save the earth. Moreover, you save your money! Such consciousness makes the earth beautiful. It’s time we have to change our life style, in order to hand down the beautiful earth to our children!!