1 . People depend on insects to pollinate the plants that make many of the fruits, nuts and vegetables we eat. Past studies had shown urban air pollution might veil the smells insects use to find flowers. Computer models predicted this would cause problems for insects, seeking flowers for a meal. But scientists weren’t sure that would happen in real life.

James Ryalls, a biologist, and his team decided to find out if it would. Working in a field, his group crafted a system made up of large rings. Each area was open, so nearby insects could fly into it. The researchers pumped pollutant gases into these rings. Then during each field season, the scientists recorded how many times pollinators visited the flowers in each ring.

“The results were much more severe than we thought,” Ryalls says. Adding pollution “caused up to 90 percent fewer insects to be able to find the flowers that they need for food,” he says. This was in comparison to the pollutant-free rings. In some cases, only some 30 percent of the pollinating insects even entered the circles with polluted gases.

Counting insects proved easier than getting the pollution into the rings, notes Ryalls. He spent much of his time working on parts of the system that needed fixing. Along the way, gas spills occurred. “By the end of each summer experiment I smelt like a petrol station,” he says. One effect: “Insects now avoid me.”

Later, they counted seed pods on the plants. Overall, only around seven in every 10 flowers had been pollinated. That means there were far fewer seeds in polluted circles. If these were fruit or vegetable plants, there would have been far less food produced.

This study focused on insects finding flowers. But insects also use smells for communication and attracting mates. If air pollution covers those smells too, these tiny animals might face more threats to their survival.

3 . A team at Oregon State University has started a three-year study into the effects of poor air quality from wildfires on dairy cows(奶牛). In an area hit by increasingly severe and numerous wildfires, and where there are a large number of cows, identifying the impacts of wildfires on cows' milk production and welfare is vital.

Previous research from the University of Idaho has found that cows exposed to poor air quality and heat stress, which were caused by wildfires, produced around 1.3 liters less milk per day than the average. The study must be expanded in order to explore broader patterns.

Ashly Anderson, who worked on this particular study, said, “Due to climate change, we're going to be seeing more wildfires-and because of that there are going to be more animals exposed to wildfires. Being able to tell what kind of effects there are and how they might be affected in the future is very important.”

In an attempt to collect more data, Juliana Ranches and her colleague Jenifer Cruickshank have begun their three-year study. They have put 30 cows, which they refer to as “smoke cows”, out to pasture(牧场). Each time there is a wildfire event which results in an Air Quality Index measure of over 50, Ranches takes daily milk samples and blood tests. She also monitors and measures the cows' respiratory(呼吸的)rates and body temperatures.

“We're getting a clearer picture of what these cows are experiencing, through poor air quality associated with wildfires—a better understanding of the effects on them. With that information, we can start to look at the negative effects and minimize the damage," Juliana Ranches said.

As summers in Oregon become hotter and drier, wildfires are on the rise, even in western parts of the state which have not historically seen them as frequently. This study and others into the impacts of smoke on dairy cows provide important information for dairy farmers, when it comes to both the welfare of their animals and their commercial productivity.

4 . The world’s coral reefs are in bad shape. Climate change has led to coral whitening. Overfishing has disturbed the ecosystems that keep reefs healthy. Poisonous runoffs from human industry are destroying the “rainforests of the sea.” A new study has highlighted another threat to coral reefs：plastics.

Researchers analyzed corals from reefs in Southeast Asia and Australia. Almost everywhere they looked, they saw bits of plastic, including chip wrappers, Q-tips, garbage bags.

The team estimates that at least 11 billion plastic items are trapped in coral reefs in the Asia-Pacific and that number is increasing alarmingly. This could spell disaster for the world’s reefs. The likelihood of the corals developing a disease jumps from 4 to 89 percent when corals come into contact with plastics.

Further investigations are needed to determine precisely how and why plastics make coral open to different diseases. But it seems that plastic debris（碎片）slices open the skin of the corals, exposing them to bacteria.

“Plastic debris can cause damage to coral tissues by accelerating invasion of bacteria or by exhausting resources for immune system function during wound-healing processes,” the authors of the study write. Drew Harvell, co-author of the study, says that plastics also “shade the light coral needs and cut off water flow.”

It is vital to preserve the health of coral reefs for a number of reasons. Many marine creatures make their homes within the reefs. Reefs also protect coastlines from waves and tropical storms, support fishing industries and generate billions of dollars for the worldwide tourism industry every year.

Throughout the research, scientists noticed that the plastics problem was not evenly distributed. Reefs near Indonesia had the highest amount of plastic rubbish, while reefs near Australia had the lowest. This could be because Australia has the best waste removal system. It suggests that there is a relatively easy fix to the issue.

“We can clean up the problem,” Harvell told Fears. “It’s so much easier than climate change.”