Mars is blanketed by a thin, mostly carbon dioxide atmosphere -- one that is far too thin to keep water from freezing or quickly evaporating. However, geological evidence has led scientists to conclude that ancient Mars was once a warmer, wetter place than it is today. To produce a more temperate climate, several researchers have suggested that the planet was once shrouded in a much thicker carbon dioxide atmosphere. For decades that left the question, "Where did all the carbon go?"

The solar wind stripped away much of Mars' ancient atmosphere and is still removing tons of it every day. But scientists have been puzzled by why they haven't found more carbon -- in the form of carbonate -- captured into Martian rocks. They have also sought to explain the ratio of heavier and lighter carbons in the modern Martian atmosphere.

The intensity of Earth’s geomagnetic field has been dropping for the past 200 years, at a rate that some scientists suspect may cause the field to bottom out in 2,000 years, temporarily leaving the planet unprotected against damaging charged particles from the sun. This drop in intensity is associated with periodic geomagnetic field reversals, in which the Earth’s North and South magnetic poles flip polarity, and it could last for several thousand years before returning to a stable, shielding intensity.

With a weakened geomagnetic field, increased solar radiation might damage electronics — from individual pacemakers to entire power grids — and could induce genetic mutations. A reversal may also affect the navigation of animals that use Earth’s magnetic field as an internal compass.

Joe Davis is an artist who works not only with paints or pastels, but also with genes and bacteria. In 1986, he collaborated with geneticist Dan Boyd to encode a symbol for life and femininity into an E. coli bacterium. The piece, called Microvenus, was the first artwork to use the tools and techniques of molecular biology. Since then, bioart has become one of several contemporary art forms (including reclamation art and nanoart) that apply scientific methods and technology to explore living systems as artistic subjects. A review of the field, published November 23, can be found in Trends in Biotechnology.

Bioart ranges from bacterial manipulation to glowing rabbits, cellular sculptures, and--in the case of Australian-British artist Nina Sellars--documentation of an ear prosthetic that was implanted onto fellow artist Stelarc's arm. In the pursuit of creating art, practitioners have generated tools and techniques that have aided researchers, while sometimes crossing into controversy, such as by releasing invasive species into the environment, blurring the lines between art and modern biology, raising philosophical, societal, and environmental issues that challenge scientific thinking.

It's big. It's cold. And it's melting into the world's ocean.

It's Zachariae Isstrom, the latest in a string of Greenland glaciers to undergo rapid change in our warming world. A new NASA-funded study published today in the journal Science finds that Zachariae Isstrom broke loose from a glaciologically stable position in 2012 and entered a phase of accelerated retreat. The consequences will be felt for decades to come.

The reason? Zachariae Isstrom is big. It drains ice from an area of 35,440 square miles (91,780 square kilometers). That's about 5 percent of the Greenland Ice Sheet. All by itself, it holds enough water to raise global sea level by more than 18 inches (46 centimeters) if it were to melt completely. And now it's on a crash diet, losing 5 billion tons of mass every year. All that ice is crumbling into the North Atlantic Ocean.

Big hopes are riding on the 2015 United Nations climate change conference planned for Nov. 30-Dec. 11 in Paris, where more than 190 nations will strive to hammer out an international agreement aimed at lowering global temperatures through significant reductions in human-made greenhouse gas (GHG) emissions. But the meeting, known as COP21, or the 21st Session of the Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC), is also attracting a fair amount of skepticism.

For good reason: More than two decades of UN climate summit meetings have yielded limited results. The Kyoto Protocol of 1997 established GHG emissions reduction commitments for a small number of industrialized countries from 2008 to 2012, but was not ratified by the U.S. because it made no demands on developing countries. Overcoming this hurdle, the Copenhagen meeting in 2009 produced voluntary pledges from both developed and developing countries through the year 2020 that promised little headway in keeping global temperatures below the 2 degree Celsius threshold identified by the UNFCCC as necessary to avoid the most serious impacts of climate change.

Landmark research by The George Institute for Global Health has found that exercise can save lives, with an increase in the number of steps walked each day having a direct correlation with long term mortality.

Study author Professor Terry Dwyer said this was the first time research had been able to make the link between exercise, measured directly through pedometers, and reduced mortality over time in people who appeared healthy at the outset.

'Inactivity is a major public health problem, with conditions like obesity costing the economy tens of billions of dollars every year,' Prof Dwyer said. 'This shows more clearly than before that the total amount of activity also affects life expectancy.

Human activities, such as greenhouse gas emissions and land use, influenced specific extreme weather and climate events in 2014, including tropical cyclones in the central Pacific, heavy rainfall in Europe, drought in East Africa, and stifling heat waves in Australia, Asia, and South America, according to a new report released today. The report, “Explaining Extreme Events of 2014 from a Climate Perspective” published by the Bulletin of the American Meteorological Society, addresses the natural and human causes of individual extreme events from around the world in 2014, including Antarctica. NOAA scientists served as three of the five lead editors on the report.

"For each of the past four years, this report has demonstrated that individual events, like temperature extremes, have often been shown to be linked to additional atmospheric greenhouse gases caused by human activities, while other extremes, such as those that are precipitation related, are less likely to be convincingly linked to human activities,” said Thomas R. Karl, L.H.D., director of NOAA’s National Centers for Environmental Information. 

Researchers at the University of California released a study today indicating that rat poisons increasingly pose a significant risk for California’s imperiled Pacific fishers, small, forest-dwelling mammals that are protected under the California Endangered Species Act. The study shows that increasing numbers of fishers are being exposed to, and dying from, greater varieties of rat poisons, or rodenticides, found at illegal marijuana farms. It also affirms reports and data from across the state that rodenticides continue to poison and kill numerous California wildlife species. 

“These poisons are silently killing our country’s most majestic wildlife by indiscriminately causing animals to literally bleed to death from the inside out,” said Jonathan Evans, environmental health legal director at the Center for Biological Diversity. “It’s time to ban these poisons from the market to protect fishers, bald eagles, great horned owls and kit foxes from a painful, gruesome fate.”

Germany's Volkswagen said Tuesday (3 November) an internal probe had found that 800,000 more vehicles showed "inconsistencies" on carbon dioxide emissions, including the first petrol engines.

Among the engines affected are 1.4, 1.6 and 2.0 litre motors of VW, Skoda, Audi and Seat vehicles, said a VW spokesman, adding that these cars had been found to be releasing more of greenhouse gas CO2 than previous tests had shown.

At least one petrol engine is concerned, the company said.

Annual snow accumulation on West Antarctica’s coastal ice sheet increased dramatically during the 20th century, according to a new study published today (Wednesday 4 November) in the American Geophysical Union journal Geophysical Research Letters. The last three decades saw more snow build up on the ice sheet than at any other time in the last 300 years.

The research gives scientists new insight into Antarctica’s ice sheet. Understanding how the ice sheet grows and shrinks over time enhances scientists’ understanding of the processes that impact global sea levels.

The new study used ice cores to estimate annual snow accumulation from 1712 to 2010 along the coastal West Antarctic. Until 1899, annual snow accumulation remained steady, averaging 33 and 40 centimeters (13 and 16 inches) water, or melted snow, each year at two locations.