A new analysis of ice-core climate data, archeological evidence and ancient pollen samples strongly suggests that agriculture by humans 7,000 years ago likely slowed a natural cooling process of the global climate, playing a role in the relatively warmer climate we experience today.

A study detailing the findings is published online in a recent edition of the journal Reviews of Geophysics, published by the American Geophysical Union.

“Early farming helped keep the planet warm,” said William Ruddiman, a University of Virginia climate scientist and lead author of the study, who specializes in investigating ocean sediment and ice-core records for evidence of climate fluctuations.

A dozen years ago, Ruddiman hypothesized that early humans altered the climate by burning massive areas of forests to clear the way for crops and livestock grazing. The resulting carbon dioxide and methane released into the atmosphere had a warming effect that “cancelled most or all of a natural cooling that should have occurred,” he said.

That idea, which came to be known as the “early anthropogenic hypothesis” was hotly debated for years by climate scientists, and is still considered debatable by some of these scientists. 

The most efficient way to clean up ocean plastics and avoid harming ecosystems is to place plastic collectors near coasts, according to a new study.

Plastic floating in the oceans is a widespread and increasing problem. Plastics including bags, bottle caps and plastic fibres from synthetic clothes wash out into the oceans from urban rivers, sewers and waste deposits.

A UC Davis scientist flying in a pollution-detecting airplane provided the first, and so far only, estimates of methane emissions spewing from the Aliso Canyon Natural Gas Storage Facility in Southern California since the leak began on Oct. 23, 2015.

Those estimates were provided to the California Air Resources Board in November. Pilot and UC Davis project scientist Stephen Conley continues to measure emissions from the still uncontrolled leak, which has displaced thousands of residents in the affluent Porter Ranch neighborhood in northern Los Angeles. On Jan. 6, Gov. Jerry Brown declared a state of emergency in the community.

To date, Conley estimates that the leak has emitted nearly 80,000 tons of methane, or about 1,000 tons per day.

Last week, the California Air Resources Board (CARB) said “no deal” to Volkswagen’s proposal to buy back some of the vehicles that were outfitted with cheat devices. According to CARB, the plan, which would see the recall of only a fraction of the 600,000 U.S. cars affected in the latest VW scandal, does “not adequately address overall impacts on vehicle performance, emissions and safety,” and would not fix the cars’ pollution problems quickly enough.

Scientists have shown that a process known as oxidative stress is at work during encounters between certain nanoparticles and immune cells, selectively modifying proteins on macrophages, a type of immune cell. The findings, by researchers at the Department of Energy's Pacific Northwest National Laboratory, were published in the journal ACS Nano.

While oxidative stress is a common way for cell damage to occur, the findings were a surprise in some ways.

"Oxidative stress is occurring selectively even at low levels of exposure to nanoparticles," said Brian Thrall, a nanotoxicology expert at PNNL and a corresponding author of the study. "We've demonstrated an approach that is sensitive enough to detect effects of nanoparticles on macrophages long before those cells die. This gives us the opportunity to understand the most sensitive cellular targets of oxidative stress and the pathways involved more completely than before.

"This is important information for understanding how nanoparticles can alter cell function and for beginning to identify functions that allow cells to adapt versus those that are potentially involved in adverse effects," Thrall added.

An ongoing methane gas leak at a facility in Southern California — what’s been called “the nation’s biggest environmental disaster since the BP oil spill” — has officially been declared an emergency by Governor Jerry Brown.

Natural gas, or methane, first started leaking from Southern California Gas Co.’s Aliso Canyon storage facility on October 23 last year.

Some 2,300 homes have been evacuated in nearby Porter Ranch, a neighborhood of Los Angeles, after residents began experiencing nosebleeds, rashes, headaches and other serious health impacts due to the gas leak and the sulfur-like smell that is blanketing their community.

Today, the U.S. Environmental Protection Agency (EPA) and the National Institutes of Health’s (NIH) National Center for Advancing Translational Sciences (NCATS), and NIH’s National Toxicology Program (NTP) within the National Institute of Environmental Health Sciences (NIEHS) are announcing a new challenge that will award up to $1 million to improve the relevance and predictivity of data generated from automated chemical screening technology used for toxicity testing.

Out of thousands of chemicals in commerce today, very few have been fully evaluated for potential health effects. Scientists from EPA, NIEHS/NTP, and NCATS are using high-throughput screening (HTS) assays to evaluate the potential health effects of thousands of chemicals. High-throughput screening uses automated methods that allow for a large number of chemicals to be rapidly evaluated for a specific type of biological activity.

Meeting the Paris Climate Agreement goal of limiting the increase in the global average temperature to well below two degrees Celsius compared to pre-industrial levels will require increased use of renewable energy and reducing the CO2 intensity of fossil energy use.

The intermittency of when the wind blows and when the sun shines is one of the biggest challenges impeding the widespread integration of renewable energy into electric grids, while the cost of capturing CO2 and storing it permanently underground is a big challenge for decarbonizing fossil energy.

However, researchers from Lawrence Livermore National Laboratory, Ohio State University, University of Minnesota and TerraCOH, Inc. think they’ve found an answer to both of these problems with a large-scale system that incorporates CO2 sequestration and energy storage.

Two-and-a-half billion people worldwide have no access to safe, durable sanitation systems. Brian Arbogast, director of the water, sanitation and hygiene programme at the Bill & Melinda Gates Foundation, tells SciDev.Net how innovative toilet technologies and business models could help fix this — and help communities cope with the devastation of climate change.

How does climate change impact sanitation?

With sea levels rising, you have flooding that causes huge health problems. As latrines and septic tanks get flooded and waste goes into the streets and streams, it can carry a lot of disease, including cholera, dysentery and typhoid.

The problem is that the world has only one gold standard for sanitation, which is having flush toilets connected to sewer lines, that are further connected to big and expensive wastewater treatment plants. Growing cities that already have water shortages may not have enough water for everybody to bathe and cook, let alone to flush toilets. So, are these cities going to follow the same path we have taken for the last century in developed cities?

The U.S. Department of Justice, on behalf of the U.S. Environmental Protection Agency, today filed a civil complaint in federal court in Detroit, Michigan against Volkswagen AG, Audi AG, Volkswagen Group of America, Inc., Volkswagen Group of America Chattanooga Operations, LLC, Porsche AG, and Porsche Cars North America, Inc. (collectively referred to as Volkswagen). The complaint alleges that nearly 600,000 diesel engine vehicles had illegal defeat devices installed that impair their emission control systems and cause emissions to exceed EPA’s standards, resulting in harmful air pollution. The complaint further alleges that Volkswagen violated the Clean Air Act by selling, introducing into commerce, or importing into the United States motor vehicles that are designed differently from what Volkswagen had stated in applications for certification to EPA and the California Air Resources Board (CARB).

“With today’s filing, we take an important step to protect public health by seeking to hold Volkswagen accountable for any unlawful air pollution, setting us on a path to resolution,” said Cynthia Giles, assistant administrator for enforcement and compliance assurance at EPA. “So far, recall discussions with the company have not produced an acceptable way forward. These discussions will continue in parallel with the federal court action.”

“Car manufacturers that fail to properly certify their cars and that defeat emission control systems breach the public trust, endanger public health and disadvantage competitors,” said Assistant Attorney General John C. Cruden for the Justice Department’s Environment and Natural Resources Division. “The United States will pursue all appropriate remedies against Volkswagen to redress the violations of our nation’s clean air laws alleged in the complaint.”