TED演讲：改变荒漠现状,扭转气候变化(4)

 　　Clearly, we have never understood what is causing desertification, which has destroyed many civilizations and now threatens us globally.  显然，我们从未明白什么导致了荒漠化，这种荒漠化已经毁掉了很多的文明社会，而现在对我们的威胁是全球性的。

　　We have never understood it. Take one square meter of soil and make it bare like this is down here,  我们从来都没有搞清楚过。像这样一平方米的土壤表面像下面这样程度的裸露着，

　　and I promise you, you will find it much colder at dawn and much hotter at midday than that same piece of ground if it's just covered with litter, plant litter.  我敢说，它会比被植被覆盖的地方，同样的大的地方，黎明的时候会冷得多，中午时会热得多。

　　You have changed the microclimate.  你已经改变了这个地方的微气候。

　　Now, by the time you are doing that and increasing greatly the percentage of bare ground on more than half the world's land, you are changing macroclimate.  现在，就像你刚才做的那样，如果世界上裸露的土地的面积快速的增长到超过了世界土地一半以上的面积，大气候就被我们改变了。

　　But we have just simply not understood why was it beginning to happen 10,000 years ago?  但是我们还是无法理解为什么这个过程一万年前就开始了？

　　Why has it accelerated lately? We had no understanding of that. 又为什么最近加快了？我们对此无法理解。

　　What we had failed to understand was that these seasonal¹ humidity environments of the world,  我们过去不了解的是，世界上这些季节性雨水充沛的环境中，

　　the soil and the vegetation developed with very large numbers of grazing animals,  伴随着植被的蓬勃生长，

　　and that these grazing animals developed with ferocious² pack-hunting predators³.  数量可观的游牧食草动物也随之而来，而这些游牧的动物又引来了凶猛的猎食者。

　　Now, the main defense⁴ against pack-hunting predators is to get into herds⁵,  游牧动物防御捕食者的主要方法是群居生活，

　　and the larger the herd⁶, the safer the individuals.  兽群越大，个体就越安全。

　　Now, large herds dung and urinate all over their own food,  大量的兽群在自己的食物上大小便，

　　and they have to keep moving, and it was that movement that prevented the overgrazing of plants,  而它们又必须不断的迁移，这些迁移过程防止了过渡放牧的现象，

　　while the periodic trampling⁷ ensured good cover of the soil, as we see where a herd has passed. 同时定期的踩踏土壤，正如这群动物路过时发生的那样，确保了土壤表面得到了很好的覆盖。

1 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

2 ferocious   

adj.凶猛的，残暴的，极度的，十分强烈的

参考例句：

• The ferocious winds seemed about to tear the ship to pieces.狂风仿佛要把船撕成碎片似的。
• The ferocious panther is chasing a rabbit.那只凶猛的豹子正追赶一只兔子。

3 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

4 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

5 herds   

兽群( herd的名词复数 )； 牧群； 人群； 群众

参考例句：

• Regularly at daybreak they drive their herds to the pasture. 每天天一亮他们就把牲畜赶到草场上去。
• There we saw herds of cows grazing on the pasture. 我们在那里看到一群群的牛在草地上吃草。

6 herd   

n.兽群，牧群；vt.使集中，把…赶在一起

参考例句：

• She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
• He had no opinions of his own but simply follow the herd.他从无主见，只是人云亦云。

7 trampling   

踩( trample的现在分词 )； 践踏； 无视； 侵犯

参考例句：

• Diplomats denounced the leaders for trampling their citizens' civil rights. 外交官谴责这些领导人践踏其公民的公民权。
• They don't want people trampling the grass, pitching tents or building fires. 他们不希望人们踩踏草坪、支帐篷或生火。