【推荐3】Next fall, when you see geese heading south for the winter, flying along in a V-formation (阵式), you might consider what science has discovered as to why they fly that way.

As each bird moves its wings, it creates uplift for the bird immediately following. By flying in a V-formation the whole group adds at least 71% greater flying range than if each bird flew on its own. People who share a common direction and sense of community can get where they are going more quickly and easily because they are traveling on the thrust (用力推) of one another.

When a goose falls out of its formation, it suddenly feels the drag and resistance of trying to go it alone and quickly gets back into formation to take advantage of the lifting power of the bird in front. If we have the same sense as a goose, we will also stay in the formation with those who are headed the same way we are.

When the head goose gets tired, it rotates (旋转) back in the wing and another goose flies to the point. It is reasonable to take turns doing demanding jobs—with people or with geese flying south. Geese honk (雁鸣) from behind to encourage those to keep up their speed. What do we say when we honk from behind?

Finally, and this is important—when a goose gets sick or is wounded by gunshots, and falls out of its formation, two other geese fall out with that goose and follow it down to lend help and protection. They stay with the fallen goose until it is able to fly or until it dies, and only then do they fly out on their own, or with another formation to catch up with their group. If we have the sense of a goose, we will stand by each other like that.

【推荐2】The tornadoes that recently hit the U.S. are some of the most destructive and deadly in history. The death in Kentucky, the hardest stricken state, reached 80 on Monday, with dozens still not included. The scale of destruction and timing of the tornadoes so late in the year — most tornadoes happen in the spring and summer — is leading to discussion about how climate change may have affected this deadly disaster.

“In my 40 years as a meteorologist (气象学家), this was one of the most shocking weather events I’ve ever experienced,” says Jeff Masters, at Yale Climate Connections. “Watching these storms on Friday night, my thought was, ‘Is no season safe?’ Extreme tornadoes in December. That was mind blowing to me.”

Unlike heat waves and floods, the connection between a warming world and tornadoes is complex (复杂的) and uncertain. Scientists have several ideas about how tornado behavior may change. Tornadoes in December are possible. But it remains to be seen whether climate change will strengthen or increase the frequency (频率) of tornadoes.

According to NOAA’s data, there has been a recorded increase in the number of observed tornadoes since 1950, which experts believe is largely because of better technology such as Doppler radar. There’s been no observed increase in the frequency of major tornadoes over time. For example, 59 of the most serious F5 tornadoes in the U.S. have happened since 1950. But if the storm that destroyed Kentucky turns out to have been an F5, it will have been the first since 2013 — bringing to an end the longest recorded period so far.

However, “given the general influence of global warming on the atmosphere, it makes sense that it should be having an effect on tornadoes too,” says Victor Gensini, an extreme weather expert at Northern Illinois University. “Rather than asking: ‘Did climate change cause this tornado?’, it’s better to operate under the thought that climate change did play a role,” he says.

While the science on climate change and tornadoes isn’t clear, meteorologists are predicting conditions benefiting tornadoes will continue this month. “ To be honest, I’m worried about the rest of the year. I don’t think we’re out of the woods yet.” Gensini says.

【推荐3】Climate change is perhaps the key issue of our time. Often, however, it is presented to us as being so abstract that it seems impossibly distant. For those of you looking for something a little more concrete, a new report suggests that the effects of climate change may significantly affect coffee.

The report, put out by The Climate Institute, describes the effects of climate change on various coffee-growing nations and the resultant effects on the plants and those who grow them.

Coffee Arabica plants, which produce 70% of all commercial coffee, can be adversely affected by even a half-degree change in typical weather conditions. This sensitivity to temperature puts the plant at increased risk of the effects of climate change.

In Central America the average temperature has risen by a full degree Celsius since 1960. In Ethiopia the average temperature has increased by l. 3 degrees. This increase is enough to have notable effects on the plants. In Tanzania the productivity per hectare of coffee has fallen by half since the 1960s due to changes in temperature.

Indeed, studies claim that by 2050 the area of the world suitable for growing coffee will be cut by half. Coffee production is likely to then be pushed to higher elevations(海拔) to take advantage of lower temperatures, but this will not be enough to make up for lost lowland areas.

Coffee is the second most traded goods by developing nations, and the inability of producer nations to export it could cause dramatic chain reactions in their economies.Millions of people make a living in the production, processing, transport, and sale of coffee;their livelihoods would stand to take a blow as growing areas decrease and prices rise.

As the temperature keeps rising, your cup of coffee will become much more expensive,and it may also carry an aftertaste bitterer than usual, for all those workers in the coffee belt left without the means to make a living as conditions worsen. Not only that, but the economic effects will cost the West millions in increased foreign aid.