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A new study, published today in the International Journal of Epidemiology [1], has dismissed the concept of 'fat but fit'. In contrast, the results from the new study suggest that the protective effects of high fitness against early death are reduced in obese people. 

Although the detrimental effects of low aerobic fitness have been well documented, this research has largely been performed in older populations. Few studies have investigated the direct link between aerobic fitness and health in younger populations. This study by academics in Sweden followed 1,317,713 men for a median average of 29 years to examine the association between aerobic fitness and death later in life, as well as how obesity affected these results. The subjects' aerobic fitness was tested by asking them to cycle until they had to stop due to fatigue.

Climate change is rapidly warming lakes around the world, threatening freshwater supplies and ecosystems, according to a new NASA and National Science Foundation-funded study of more than half of the world's freshwater supply.

Using more than 25 years of satellite temperature data and ground measurements of 235 lakes on six continents, this study -- the largest of its kind -- found lakes are warming an average of 0.61 degrees Fahrenheit (0.34 degrees Celsius) each decade. The scientists say this is greater than the warming rate of either the ocean or the atmosphere, and it can have profound effects.

The research, published in Geophysical Research Letters, was announced Wednesday at the American Geophysical Union meeting in San Francisco.

As nations across the globe negotiate how to reduce their contributions to climate change, researchers at Penn are investigating just how the coming changes will impact the planet. What's clear is that the effect extends beyond simple warming. Indeed, the very physics and chemistry of the oceans are also shifting, and are forecast to change even more in the coming decades.

These changes have implications for, among other things, the single-celled organisms that comprise the base of the ocean's food web and are responsible for half of the world's photosynthetic activity: phytoplankton. Not only are phytoplankton sensitive to changes in climate, they also contribute to those changes, as they can remove carbon from the atmosphere and store it deep in the ocean when they die.

A micrograph of phytoplankton. Like plants on land, phytoplankton growth is controlled by environmental factors such as light, nutrients, and temperature.

Fuel economy is at record highs and carmakers have surpassed strict greenhouse gas emissions standards for the third straight year, according to the Environmental Protection Agency, which released a pair of annual reports about the U.S. fleet of cars and trucks Wednesday.

Overall, fuel economy for vehicles in the U.S. did not budge from last year's record high of 24.3 miles per gallon, the EPA says. The figure includes a new high of 20.4 mpg for trucks, vans and SUVs from model year 2014.

The JRC has been looking into the risks of space weather impact on critical infrastructures. A new report explores the rail sector's vulnerability and the potential impacts, in particular through interdependencies with other infrastructures. Awareness among operators and regulators worldwide is currently limited and vulnerabilities across the rail sector need to be identified, authors say.

Solar activity affects the space environment surrounding the Earth. This so-called space weather can disrupt and damage critical infrastructure in space and on the ground, including satellites, aviation, road and marine transport, banking and power grids. Society relies on these infrastructures and services, which have become inter- dependent and are therefore more vulnerable to space weather.