What is the ozone layer and what does it do?

Recent Met Office forecasts for UV are indicating low to moderate levels, however there is a possibility that the levels may in fact be much higher than this today.

Scientists say high UV levels are due to changes in the ozone layer.

Migrating birds sprint in spring, but take things easy in autumn

Passerine birds, also known as perching birds, that migrate by night tend to fly faster in spring than they do in autumn to reach their destinations. This seasonal difference in flight speed is especially noticeable among birds that only make short migratory flights, says researcher Cecilia Nilsson of Lund University in Sweden, in Springer's journal Behavioral Ecology and Sociobiology.

Air pollution responsible for more than 2 million deaths worldwide each year, experts estimate

More than two million deaths occur worldwide each year as a direct result of human-caused outdoor air pollution, a new study has found.

In addition, while it has been suggested that a changing climate can exacerbate the effects of air pollution and increase death rates, the study shows that this has a minimal effect and only accounts for a small proportion of current deaths related to air pollution.

The study, which has been published Publishing's journal Environmental Research Letters, estimates that around 470,000 people die each year because of human-caused increases in ozone.

Temperature most significant driver of world's tallest trees

Understanding forest biodiversity and how carbon dioxide is stored within trees is an important area of ecological research. The bigger the tree, the more carbon it stores and a study in New Phytologist explores global variance in tree height, identifying temperature as the most important factor behind the tallest species.

Height gives canopy trees, the focus of much forest carbon research, a competitive advantage as they can place leaves at higher light levels while suppressing their competitors. Height also allows for wind-dispersed pollen and fruits to travel further.

The new study explores the role of temperature in driving tree height, a study which may allow us to forecast how forests adapt to climate change. The research examined the temperature-driven physiological model of tree height in order to explain the thermal climates in which the tallest individuals of the tallest tree species grow.

The tallest specimens of the world's nine tallest tree species were found to grow in climates with an unusually small seasonal temperature variation, which accounted for only 2.1% of global land area. In contrast their distance from the equator ranged from 3900 to 5500 km, their altitude above sea level from 50 to 1750 m, and the distance between the most distant localities ranged from 2700 km in Australia to 1400 km in western North America.

Insights on whale shark populations and evidence for their historic rise, recent decline

In the largest study on the genetics of whale sharks conducted to date, researchers found that the world's biggest fish likely exist in 2 distinct populations with minimal connectivity between the Indo-Pacific and the Atlantic Ocean. The findings suggest that mixing of whale sharks between the Indian and Atlantic was and is rare.