Enviroment

In the first half of the 19th century, a series of large volcanic eruptions in the tropics led to a temporary global cooling of Earth's climate. That Alpine glaciers grew and subsequently receded again during the final phase of the so-called Little Ice Age was due to a natural process. This has now been proven by PSI researchers on the basis of ice cores.

PSI researchers have developed an experimental chamber in which they can recreate atmospheric processes and probe them with unprecedented precision, using X-ray light from the Swiss Light Source SLS. In the initial experiments, they have studied the production of bromine, which plays an essential role in the decomposition of ozone in the lower layers of the atmosphere. In the future, the new experiment chamber will also be available for use by researchers from other scientific fields.

The Laboratory for Energy Systems Analysis at the Paul Scherrer Institute PSI is investigating how Switzerland’s electricity supply might look, up to the year 2050, under a variety of boundary conditions. On the basis of their calculations, the lab’s researchers are able to generate insights on possible future developments of the energy sector, for example, determine how an ambitious reduction in CO₂ emissions could be achieved at the lowest possible cost.

Until now, the onset of copper production in South America was still unclear. Hardly any written records or artefacts from the early high cultures in Peru, Chile, and Bolivia have been preserved. Now, however, researchers of the Paul Scherrer Institute PSI in Villigen (Switzerland) have tracked down the evidence. Through analysis of ice from the Illimani glacier in the Bolivian Andes, they found out that copper was being mined and smelted in South America since around 700 BC.

Atmospheric scientist Julia Schmale is starting out on a three-month research cruise around the Antarctic. There she will be searching for the cleanest air still to be found on our planet.

Clouds consist of tiny droplets. These droplets form when water condenses around so-called aerosols – small particles in the atmosphere. To understand how in turn aerosols come into existence scientists have now created a comprehensive computer model simulation based on profound experimental data. This simulation revealed that in addition to sulphuric acid, two other substances are crucially involved in the formation of aerosols: organic compounds and ammonia. These results have now been published in the renowned journal Science.

Researchers have shown how fine particles are formed from natural substances in the atmosphere. These findings will improve our knowledge about clouds in the pre-industrial era and thus will contribute to a more accurate understanding of both the past and future evolution of our climate.

Forest trees use carbon not only for themselves; they also trade large quantities of it with their neighbours. The extensive carbon trade among trees – even among different species – is conducted via symbiotic fungi in the soil.

In a deep geological repository, low and intermediate level radioactive waste from nuclear applications is solidified by cementitious materials for several thousand years. Researchers from the Paul Scherrer Institute and the Karlsruhe Institute of Technology have now demonstrated how cement limits the mobility of those radioactive substances. The new findings improve our understanding of the processes involved in this early phase of deep geological disposal.

For years, studies have proved that fine dust from petrol engines can damage our health. Modern engine technology does not help, either, as researchers from the University of Bern and the Paul Scherrer Institute (PSI) reveal.

Until it was banned, leaded gasoline dominated the manmade lead emissions in South AmericaLeaded gasoline was a larger emission source of the toxic heavy metal lead than mining in South America – even though the extraction of metals from the region’s mines historically released huge quantities of lead into the environment. Researchers from the Paul Scherrer Institute PSI and the University of Bern have discovered evidence of the dominance of leaded gasoline based on measurements in an ice core from a Bolivian glacier. The scientists found that lead from road traffic in the neighbouring countries polluted the air twice as heavily as regional mining from the 1960s onwards. The study is to be published in the journal Science Advances on 6 March 2015.

As glaciers increasingly melt in the wake of climate change, it is not only the landscape that is affected. Thawing glaciers also release many industrial pollutants stored in the ice into the environment. Now, within the scope of a Swiss National Science Foundation project, researchers from the Paul Scherrer Institute (PSI), Empa, ETH Zurich and the University of Berne have measured the concentrations of a class of these pollutants – polychlorinated biphenyls (PCB) – in the ice of an Alpine glacier accurately for the first time.

On winter smog days in Switzerland wood burning is the main source of harmful carbon-containing fine particles. This is revealed by a large-scale Swiss study on fine particle pollution conducted over a five-year period by scientists at the Paul Scherrer Institute (PSI), the University of Bern and ETH Zurich.

The causes of China's record level fine particulate pollution in winter 2013At the beginning of 2013 a greyish-brown blanket of smog lay over large areas of China for several months. The fine particle pollution was higher by 1 to 2 orders of magnitude than the levels normally measured in Western Europe and the United States. An international team of researchers under the lead of the Paul Scherrer Institute PSI and the Institute of Earth Environment, Chinese Academy of the Sciences revealed the causes of the airpocalypse. The study published in the journal Nature also describes what steps are to be taken to prevent an environmental crisis of this kind in the future.

Scientists know that clouds have a net cooling effect on our planet but the exact magnitude of that cooling effect is not exactly known. A new study by the CLOUD experiment (Cosmics Leaving OUtdoor Droplets) at CERN sheds light on the very first step of cloud formation, thereby contributing to a better understanding of the cloud-climate connection. The study was led by scientists at the Paul Scherrer Institute (PSI) and was published on 16 May 2014 in the journal Science

In some towns small mopeds cause more air pollution than carsNot cars or trucks, but mopeds with their two-stroke engines are the main source of fine particles and other air contaminants in many towns in Asia, Africa and southern Europe. This is revealed by the study of an international research team headed up by researchers at the Paul Scherrer Institute PSI. The reasons for the high emissions are the combustion properties in two-stroke engines and the overly lenient emission requirements for small two-wheelers. The study findings are to be published on 13 May 2014 in the journal Nature Communications.

Researchers from the Paul Scherrer Institute (PSI) and the Hungarian Academy of Sciences joined forces within an EU project to investigate the basic properties of argillaceous rocks in a repository for high-level radioactive waste. As the results reveal, the insights gained so far for Opalinus Clay can be transferred also to the Boda Clay found in Hungary.

With ecoinvent, the Paul Scherrer Institute and its partners at ETH Zurich, ETH Lausanne, Empa and Agroscope have been running the world’s leading database for life cycle inventories for over ten years. The latest ecoinvent version 3 collects new data in areas such as electricity generation, agriculture, transport, mining and chemicals. In the power sector, which is significant for life cycle assessments, the database now covers over 80 per cent of the global production. And technology that has not been considered thus far such as enhanced geothermal systems is to be included in ecoinvent from now on. The result is more accurate ecological assessments of products and services

Aerosols are small particles in the atmosphere. They can influence the global climate by way of direct absorption or scattering of solar radiation, or by acting as nuclei for cloud formation. Efforts by scientists to exactly quantify these effects and then improve climate models are impeded by the lack of a global network of aerosol measurement stations. To remedy this situation, researchers at the Paul Scherrer Institute to facilitate continuous aerosol measurements at sites where the paucity of data is the greatest.

PSI-researcher Martin Gysel receives prestigious European funding (ERC Consolidator Grant) for his studies on the role of soot in cloud formation and global warming.