【英语时差8,16】全球变暖的元凶--煤烟

 Soot¹ was cause for a different concern in another recent study. Scientists with the American space agency, NASA, suggest it as a major cause of global warming. The study says the problem is how soot interacts with snow and ice. Snow and ice have highly reflective surfaces. A lot of the sunlight that hits them is forced back up toward the sky. This helps prevent melting. But the scientists say the problem develops when snowflakes pick up fine particles of soot as they fall. The black carbon in soot reduces the ability of snow and ice to reflect sunlight. Instead, the black soot absorbs the energy and warmth, and causes melting. The scientists say the soot causes the melting season of glaciers² to begin earlier and last longer. This has a large effect, they say, because wet snow is much darker than dry snow. So the problem increases. The scientists estimate that soot is two times as effective as carbon dioxide in changing surface air temperatures. But they say the good news is that cleaner diesel³ engines and other technologies are being developed to reduce soot.

1 soot   

n.煤烟，烟尘；vt.熏以煤烟

参考例句：

• Soot is the product of the imperfect combustion of fuel.煤烟是燃料不完全燃烧的产物。
• The chimney was choked with soot.烟囱被煤灰堵塞了。

2 glaciers   

冰河，冰川( glacier的名词复数 )

参考例句：

• Glaciers gouged out valleys from the hills. 冰川把丘陵地带冲出一条条山谷。
• It has ice and snow glaciers, rainforests and beautiful mountains. 既有冰川，又有雨林和秀丽的山峰。 来自英语晨读30分（高一）

3 diesel   

n.柴油发动机，内燃机

参考例句：

• We experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
• My tractor operates on diesel oil.我的那台拖拉机用柴油开动。