1-stem 阻止，遏制

2-curb 限制，抑制

Efforts to stem the spread of the novel coronavirus are changing the way people work and play-and those changes are temporarily curbing greenhouse gas emissions.

3-the tip of the iceberg 冰山一角

Fears of the outbreaks already led to a drop in passenger demand in January, according to the industry group International Air Transport Association, which called it " just a tip of the iceberg ".

4-dip 减少，下降

That dip in travel means less pollution from planes.

5-curtail 减少，缩减

6-lean 不景气的

Now, as both business and leisure travel curtailed, airlines are facing a near future, that is both cleaner and economically leaner.

7-keep sth/sb out of 阻止……进入

To meet that requirement, airlines need to spend money on renewable energy or tree-planting project that help keeping heat-trapping gases out of the atmosphere.

8-backtrack 倒退，变卦＋on

9-carbon offset 碳补偿

10-push for 争取，追求

11-lax 宽松的

Some environmentalists worry that facing this increased pressure, airlines may backtrack on their climate pledges or push for more lax standards on the quality of carbon offsets they are allowed to purchase.

12-keep one's eye on the ball 持续关注

It also has to keep its eye on the ball of the long term climate issue - which is not going away.