Boys and girls, do you understand how much environmental knowledge, know? Protecting the environment is the human consciously protect natural resources and make them get reasonable use, to prevent the pollution of natural environment and damage. Now, the earth environment gradually destroyed. Because there are many environmental destruction, someone for reason, there are natural causes. But most people are deforestation, litter and other factors.
As far as I know from the Internet, 30 years from 1950 to 1950, more than half of the world's forests have been destroyed, one half of the forest land into desert in Africa. Green vegetation is present in the human nature of "being" of life. World the 50 years after the 20th century, however, damage to people and animals live in green environment, green vegetation is in a recession, the global soil loss to increase to 25.4 billion tonnes a year, desertification, soil is at an annual rate of 5 to 7 square kilometers expanded rapidly.
In 1998, through China the earth in the Yangtze river, the songhua river, such as large rivers, lost the past gentle beautiful smiling face, out of ferocious ferocious terror. Raging storms, the roaring river, rolled up the flood peak, and again engulfed entire villages, pieces of land, cities and counties, each factory, a school... Oh my god, this is what a loss!
In recent years, because humans cut down trees, also damage the environment, make the vegetation destroyed, causing the phenomenon of land desertification, soil erosion, etc. Trees also gradually reduce, then, to absorb carbon dioxide, large amounts of carbon dioxide make the air become warm, creates the world present situation: the greenhouse effect.
Campus is always has a beautiful scenery, now everyone don't protect the environment, it makes our environment destruction. Look at the corner of the street is filled with plastic bags, cigarette butts. On the flower beds in the neighborhood is filled with dirt, we should protect everything we have good resources. I have people here don't protect environment under the condition of reverie: one day, the tree my grandfather in the beautiful scenery in a rest, suddenly to a few people, to prepare for a picnic here. Not for a moment here a beautiful environment becomes dirty, but this a few people or ignored. "The men finally walked" the tree grandpa sad cried, alas! The men got the cigarette butts on the grass, the ground filled with plastic bags, bottle. A few days later the tree grandpa dyspnea died because of bad environment.
同學們，環保知識你們了解多少，知道多少?保護環境是人類有意識地保護自然資源並使其得到合理的利用，防止自然環境受到污染和破壞。現在，地球上環境逐漸遭到破壞。環境遭破壞的原因有許多，有人為原因，也有自然原因。不過大多數是人們亂砍亂伐，亂扔垃圾等因素。
據我從網上了解，自1950年到1980年30年間，全世界有一半以上的森林面積被毀，其中非洲的二分之一林地變成不毛之地。綠色植被是大自然贈於人類的“生命之被”。可是，世界進入20世紀50年之後，人和動物賴以生存的綠色環境遭到破壞，綠色植被正在衰退，全球土壤失量現以增加到每年254億噸，沙漠化土壤正以每年5-7萬平方公里的速度迅速擴展。
1998年時，流經中國大地的長江、松花江等大江大河，失去了往日溫柔美麗的笑臉，露出了兇猛恐怖的猙獰。肆虐的暴雨，咆哮的江水，捲起了一次次洪峰，吞噬了一個個村莊，一片片田地，一個個市縣，一座座工廠，一所所學校……天哪，這是多么大的損失啊!
近幾年，也因為人類大量砍伐樹木、破壞環境，使植被遭到破壞，造成了土地沙漠化、水土流失等現象。樹木也漸漸減少，於是，二氧化碳無法吸收，大量的二氧化碳使空氣變得溫暖，就造成了世界上目前出現的狀況：溫室效應。
園裡都總有一處美麗的風景，可現在大家都不保護環境，這才使我們的環境遭受破壞。你看街道上的角落到處都有塑膠袋，菸頭。小區裡的花壇上到處都有髒東西，我們應該保護好我們現在所擁有的一切美好資源。我就在這人們不保護環境的情況下遐想：一天，大樹爺爺在一處美麗的風景休息，突然來了幾個人，準備在這裡野餐。沒一會兒這裡美麗的環境一下變得髒兮兮了，但這幾個人還是置之不理。“這幾個人終於走了”大樹爺爺悲哀的叫著，唉!那幾個人把小草上弄上了菸頭，地上掉滿塑膠袋，瓶子。沒過幾天大樹爺爺因環境不好呼吸困難死去了。