第1个回答 2015-12-08
1. Human beings are dependent on the Earth’s diversity of species. Wild species play a vital role in the maintenance of the planet’s ecological functions, yet every day on the planet 40-100 species become extinct.
2. Human life cannot exist in the absence of complicated interactions of millions of species in biological systems.
3. 50,000 plant an animal species disappear each year due to tropical deforestation, expanding agriculture and human settlement.
4. Human activities impact the environment, including clearing agriculture land; air, land and water pollution; urban and suburban development; and the introduction of invasion or non-native wildlife species. If land and wildlife are poorly managed, human being will risk fragmenting habitat.
5. We are living in the midst of a great chemical experiment, and some serious consequences are becoming apparent to scientist. More than two billion pounds of chemicals are spewed into the air each year. These chemicals are brewing a disastrous stew, resulting in an atmosphere crisis. The greatest consequences of the atmosphere crisis may be global warming and the ozone depletion. If human kind wants to survive well into the next millennium, we must stop this horrible destruction of our own environment.
6. The earth appears to be warming due to the greenhouse effect. Scientists estimate that the average temperature could climb about 2 degrees Celsius in 20 years. This change in the global climate would have disastrous results, including drought, coastal flooding and increased species extinction. And, scientists have discovered a hole in the ozone layer. The ozone layer is the only protection for life on Earth against deadly ultraviolet radiation from the Sun. Once the ozone layer is completely destroyed, all life on Earth will cease to exist, killed by the deadly radiation. The planet will become a barren rock devoid of all life.
7. It allows for an unbelievably large amount of downloads and uploads of information, music,videos and all sorts of other things, as it is the engine of the information superhighway of our Information Era, in witch we live.本回答被网友采纳