The news is mainly about______. [originaltext] Scientists say that nighttime

Scientists say that nighttime flights are much more damaging to the environment than daytime air travel. In new research published in the journal Nature, they say vapor trails produced by aircrafts do far more damage during the night. The reason is condensation water vapour emitted from the hot engines of aircraft condensing into trailing clouds.
    The scientists say that in daylight the trails act like mini clouds, they are good for the environment because their white color deflects the Sun’s rays and reduces temperatures. At night when the sun goes down this positive benefit is lost. The impact of night trail is surprisingly large. In the United Kingdom only a quarter of flights take place in darkness, but this accounts for up to 80% of greenhouse effect from condensation.