articles

The amount of methane gas escaping from the ground during the long cold period in the Arctic each year and entering Earth's atmosphere is likely much higher than estimated by current carbon cycle models, concludes a major new study led by San Diego State University and including scientists from NASA's Jet Propulsion Laboratory, Pasadena, California.

The study included a team comprising ecologists Walter Oechel (SDSU and Open University, Milton Keynes, United Kingdom) and Donatella Zona (SDSU and the University of Sheffield, United Kingdom) and scientists from JPL; Harvard University, Cambridge, Massachusetts; the National Oceanic and Atmospheric Administration, Boulder, Colorado; and the University of Montana, Missoula. The team found that far more methane is escaping from Arctic tundra during the cold months when the soil surface is frozen (generally from September through May), and from upland tundra, than prevailing assumptions and carbon cycle models previously assumed. In fact, they found that at least half of the annual methane emissions occur in the cold months, and that drier, upland tundra can be a larger emitter of methane than wet tundra. The findings challenge critical assumptions in current global climate models. The results are published this week in the Proceedings of the National Academy of Sciences.

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.

Accelerating rates of sea-level rise linked to climate change pose a major threat to coastal marshes and the vital carbon capturing they perform. But a new Duke University study finds marshes may be more resilient than previously believed. 

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. 

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.