Earth Sciences

Credit: Don Davis

By Claire Belcher, University of Exeter and Rory Hadden, University of Edinburgh

The asteroid that wiped out the dinosaurs set off an intense heat wave that briefly boiled the Earth’s atmosphere – but it didn’t burn off all the plants.

The debate over wind turbines is heated, so it's best to rely on solid science. Fir0002/Flagstaffotos/Wikimedia Commons, CC BY-NC

By Jacqui Hoepner, Australian National University and Will J Grant, Australian National University

There are tens of thousands of human-made chemicals circulating today and some have been bad despite studies that didn't initially find harm, yet almost every chemical is under siege by environmental groups, and they all claim science is on their side.

Everything from bisphenol A used in plastics to neonicotinoid pesticides to glyphosate weed-killers are criticized by lawyers at environmental groups despite the science consensus. How can the public know which ones really pose threats to our health and environment and which ones are just studies designed to keep poisoning lab animals until they show an effect?
Sometimes the whole is greater than the sum of its parts, said Aristotle. That certainly applies to biology, where molecular motions in living systems have a macroscale effect - such as large muscles that contract due to protein motors.

A team at CNRS's Institut Charles Sadron led by Nicolas Giuseppone, professor at the Université de Strasbourg has  used this concero to make a polymer gel that is able to contract through the action of artificial molecular motors. When activated by light, these nanoscale motors twist the polymer chains in the gel, which as a result contracts by several centimeters. Another advantage is that the new material is able to store the light energy absorbed. 
A new species of dinosaur has turned out not to be a dinosaur at all, it is instead one of the large reptiles that lived before dinosaurs took over the world. But like many dinosaurs, it looked fearsome. 

Nundasuchus songeaensis was a 9-foot-long carnivorous reptile with steak knife-like teeth, bony plates on the back, and legs that lie under the body.  The basic meaning of Nundasuchus, is "predator crocodile," "Nunda" meaning predator in Swahili, and "suchus" a reference to a crocodile in Greek.

As the Earth warms and glaciers all over the world begin to melt, the natural concern has been how all of that extra water will contribute to sea level rise.

Less considered is what happens to all of the organic carbon found in those glaciers when they melt. A new paper estimates what could happen if major ice sheets break down.

Glaciers and ice sheets contain about 70 percent of the Earth's freshwater and ongoing melting is a major contributor to sea level rise. But, glaciers also store organic carbon derived from both primary production on the glaciers and deposition of materials such as soot or other fossil fuel combustion byproducts.  

From the beginning of time, uranium has been part of the Earth and, thanks to its long-lived radioactivity, it has proven ideal to date geological processes and figuring out Earth’s evolution. 

Natural uranium consists of two long-lived isotopes uranium-238 and the lighter uranium-235 and  uranium isotopes leave a distinct ‘fingerprint’ in the sources of volcanic rocks, making it possible to gauge their age and origin.   

Crops genetically engineered to produce proteins from the bacterium Bacillus thuringiensis (Bt) to control insect pests have been planted on a cumulative total of more than a billion acres worldwide since 1996 and they have been very successful.

But pests evolve just like everything else and to avoid that, companies recommend a variety of strategies to avoid 'herd immunity'. Biotech companies have also introduced Bt crops called "pyramids" that produce two or more Bt toxins active against the same pest. They have been adopted in many countries since 2003, including the United States, India and Australia.

One of the biggest struggles in toxicology is creating the correct parameters so you are modeling the real world as closely as possible. It's an enormous task to model the environment with its millions of factors, so controlled studies are done using animals.

Scientists design experiments that give an animal a lot of something at once and that can tell them 'this is the threshold where more analysis is a waste of time' and perhaps also find an effect that may be worth studying in more detail. It's a time-honored technique but it's also a technique that can be exploited.

 On November 23rd, 2014, a new volcano eruption commenced on Fogo, one of the Cape Verde Islands, and it continues even now, making it the largest and most damaging eruption - and the biggest natural disaster no one in the western world was reading about it - on the archipelago for over 60 years. 

Most of the damage was caused by lava flows advancing into populated regions and numerous buildings, homes and roads were destroyed. In total, three villages have been abandoned and thousands of residents were evacuated.