Our sun will one day become a faint white dwarf star - but prior to that, for a few tens of thousands of years as its atmosphere is blown away into space  it could be surrounded by spectacular and colorful glowing clouds of ionized gas known as planetary nebulae.

"What are the radiation doses to airplane passengers from the intense bursts of gamma-rays that originate from thunderclouds?" researchers asked at a press conference during the European Geosciences Union in Vienna today.

An unusual fossil of Euphanerops, a fossil jawless fish that swam in the seas around 370 million years ago, has fins behind its anus - a pair of them.  The find makes the fish one of the first vertebrate to develop paired appendages such as fins, legs or arms. 

Long ago, obesity and high blood pressure were signs of being a wealthy elite. But the world has progressed and now even the poorest countries can eat enough to be fat. As recently as 1980 those health risks were more prevalent in countries with a higher income but a new analysis in Circulation shows that the average body mass index of the population is now just as high or higher in middle-income countries. For blood pressure, the situation has reversed among women, with a tendency for blood pressure to be higher in poorer countries.

Rising temperatures will lead to a "greening" of the Arctic by mid-century, according to a new numerical model. 

The greening not only will have effects on plant life, the researchers noted, but also on the wildlife that depends on vegetation for cover. The greening could also have a multiplier effect on warming, as dark vegetation absorbs more solar radiation than ice, which reflects sunlight.

In the paper, scientists detail their new computer projections stating that wooded areas in the Arctic could increase by as much as 50 percent over the coming decades. The researchers also show that this dramatic greening will accelerate climate warming at a rate greater than previously expected. 

Chlorogenic acids, natural substances extracted from unroasted coffee beans, can help control the elevated blood sugar levels and body weight that underpin type 2 diabetes.