Average chloride concentrations often exceed toxic levels in many northern United States streams due to the use of salt to deice winter pavement, and the frequency of these occurrences nearly doubled in two decades. Chloride levels increased substantially in 84 percent of urban streams analyzed, according to a U.S. Geological Survey study that began as early as 1960 at some sites and ended as late as 2011. Levels were highest during the winter, but increased during all seasons over time at the northern sites, including near Milwaukee, Wisconsin; Chicago, Illinois; Denver, Colorado; and other metropolitan areas. The report was published today in the journal Science of the Total Environment.

Princeton University researchers have uncovered a previously unknown, and possibly substantial, source of the greenhouse gas methane to the Earth's atmosphere. After testing a sample of abandoned oil and natural gas wells in northwestern Pennsylvania, the researchers found that many of the old wells leaked substantial quantities of methane. 

Natural gas power plants produce substantial amounts of gases that lead to global warming. Replacing old coal-fired power plants with new natural gas plants could cause climate damage to increase over the next decades, unless their methane leakage rates are very low and the new power plants are very efficient.

These are the principal findings of new research from Carnegie’s Ken Caldeira and Xiaochun Zhang, and Nathan Myhrvold of Intellectual Ventures that compares the temperature increases caused by different kinds of coal and natural gas power plants. Their work is published in Environmental Research Letters.

The climate warming caused by a single carbon emission takes only about 10 years to reach its maximum effect. This is important because it refutes the common misconception that today’s emissions won’t be felt for decades and that they are a problem for future generations. For the first time, a study conducted by Carnegie's Katharine Ricke and Ken Caldeira has evaluated how long it takes to feel the maximum warming effect caused by a single carbon emission. Their work is published in Environmental Research Letters.

Scientists have presented the most comprehensive evidence to date that climate extremes such as droughts and record temperatures are failing to change people’s minds about global warming. Instead, political orientation is the most influential factor in shaping perceptions about climate change, both in the short-term and long-term, said Sandra Marquart-Pyatt, a Michigan State University sociologist and lead investigator on the study.

The deliberate, large-scale intervention in the Earth’s climate system is not a “quick fix” for global warming, according to the findings of the UK’s first publicly funded studies on geoengineering.

The results of three projects – IAGP, led by the University of Leeds; SPICE, led by the University of Bristol; and CGG, led by the University of Oxford – are announced at an event held at The Royal Society, London, on 26 November.

Researchers from North Carolina State University have created a model that mimics how differently adapted populations may respond to rapid climate change. Their findings demonstrate that depending on a population's adaptive strategy, even tiny changes in climate variability can create a "tipping point" that sends the population into extinction.

Carlos Botero, postdoctoral fellow with the Initiative on Biological Complexity and the Southeast Climate Science Center at NC State and assistant professor of biology at Washington State University, wanted to find out how diverse populations of organisms might cope with quickly changing, less predictable climate variations. 

Small volcanic eruptions might eject more of an atmosphere-cooling gas into Earth’s upper atmosphere than previously thought, potentially contributing to the recent slowdown in global warming, according to a new study.

One of the most abrupt rises in the carbon dioxide concentration in the atmosphere at the end of the last ice age took place about 14,600 years ago. Ice core data show that the CO2 concentration at that time increased by more than 10 ppm (parts per million, unit of measure for the composition of gases) within 200 years. This CO2 increase, i.e. approx. 0.05 ppm per year, was significantly less than the current rise in atmospheric CO2 of 2-3 ppm in the last decade caused by fossil fuels. 

If you want to see into the future, you have to understand the past. An international consortium of researchers under the auspices of the University of Bonn has drilled deposits on the bed of Lake Van (Eastern Turkey) which provide unique insights into the last 600,000 years. The samples reveal that the climate has done its fair share of mischief-making in the past. Furthermore, there have been numerous earthquakes and volcanic eruptions. The results of the drilling project also provide a basis for assessing the risk of how dangerous natural hazards are for today's population. In a special edition of the highly regarded publication Quaternary Science Reviews, the scientists have now published their findings in a number of journal articles. In the sediments of Lake Van, the lighter-colored, lime-containing summer layers are clearly distinguishable from the darker, clay-rich winter layers — also called varves. In 2010, from a floating platform an international consortium of researchers drilled a 220 m deep sediment profile from the lake floor at a water depth of 360 m and analyzed the varves. The samples they recovered are a unique scientific treasure because the climate conditions, earthquakes and volcanic eruptions of the past 600,000 years can be read in outstanding quality from the cores.