The ozone layer where the ozone concentration is higher,can prevent overmuch solar ultraviolet from harming the living creatures on the earth.The depletion of the ozone layer had increased the skin cancer by 26%

　 The pollution and transfer of the waste are problems caused by indiscriminate waste discharge from production and life,inclduing the exhaust gas、waste liquor and solid waste,all of which seriously pollute the air、river、lake、sea and terrestrial environment as well as harm people's health seriously.The hazardous waste dumped by the developed countries to the sea and the developing countries direcly pollute these places and do harm to the health of the local people.According to statistics,every year from cities there is more than 6 billion garbage which covers an area of 0.5 billion square meters awaiting final disposition,and the urban per capita annual garbage is as much as 440kg.

　 Water is the fountain of life.Water seems to be everywhere,but the shortage of drinking water poses a threat to human existence.Currently,the annual water consumption reached 7,000 million cubic meters,accompanying water scarcity-a wake-up call for the whole human race.According to the Global Water Quality Monitoring Project,about 10% of the monitored rivers are polluted.And statistics from the UN show that currently there are over 100 countries and regions in soaring demand for domestic water,among which there are 43 countries having a serious water shortage-a threat to the existence of 2 billion people mainly distributed in Africa and the Middle East area.Many scientists predicted that water would become the scarcest resources over the 21st century.And people never wish to see their tears becoming the last drop of water on earth.

　 Forests,with an indispensable regulating effect towards the environment,are halled as "the lungs of the earth" and“the dispatching center of nature”.In order to meet the import demand of the developed countries and to meet the developing demand of farming and animal husbandry of the developing countries,large areas of forest has been consumed.The earth,asked for incontinently by mankind,is in a critically endangered status.

　 The biodiversity decline is a phenomenon of endless loss of all species caused by the destruction of ecological balance、overdevelopment of resources、environmental pollution and the introduction of foreign species.Most experts agree that 25% of the living creatures will be endangered during the next 20 to 30 years,and 5% to 15% species may die out during the 30-year period from 1990 to 2020,which means that 40 to 140 species become extinct per day.

　Land degradation and desertification is a process in which the land is downgraded and is turned into desert gradually caused by overstocking 、excess reclamation、deforestation and a series of natural factors.In the past 20 years the number of the population suffering from starvation has risen from 0.46 billion to 0.55 billion because of land degradation and desertification.