Fast Pace of Glacier Melt in the 1940s: Lower Aerosol Pollution

Gorner glacier. In the 1940s, the glaciers were melting at a faster pace than today.

(Credit: Matthias Huss / ETH Zurich)

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The most recent studies by researchers at ETH Zurich show that in the 1940s Swiss glaciers were melting at an even-faster pace than at present. This is despite the fact that the temperatures in the 20th century were lower than in this century. Researchers see the main reason for this as the lower level of aerosol pollution in the atmosphere.

In Switzerland, the increase in snow in wintertime and the glacier melt in summertime have been measured at measurement points at around 3,000 metres above sea level -- on the Clariden Firn, the Great Aletsch glacier and the Silvretta glacier -- without interruption for almost 100 years. As part of his doctoral work, Matthias Huss used this unique range of measurements to examine how climate change in the last century affected the glaciers. The work was carried out under the supervision of Martin Funk, professor and head of the Department for Glaciology at the Laboratory for Hydraulics, Hydrology and Glaciology ('VAW') at ETH Zurich, who is also co-author of the study.

Solar radiation as the decisive factor

In its work, the research team took into account the solar radiation measured on the Earth's surface in Davos since 1934. Studies over the past two decades have shown that solar radiation varies substantially due to aerosols and clouds, and this is assumed to influence climate fluctuations. Recent years have seen the emergence of the terms 'global dimming' and 'global brightening' to describe these phenomena of reduced and increased solar radiation respectively. These two effects are currently the subject of more and more scientific research, in particular by ETH Zurich, as experts feel that they should be taken into account in the climate models.

The new study, published in the journal 'Geophysical Research Letters', confirms this requirement. This is because, taking into account the data recorded for the level of solar radiation, the scientists made a surprising discovery: in the 1940s and in the summer of 1947 especially, the glaciers lost the most ice since measurements commenced in 1914. This is in spite of the fact that temperatures were lower than in the past two decades. "The surprising thing is that this paradox can be explained relatively easily with radiation," says Huss, who was recently appointed to the post of senior lecturer at the Department of Geosciences at the University of Fribourg in Switzerland.

On the basis of their calculations, the researchers have concluded that the high level of short-wave radiation in the summer months is responsible for the fast pace of glacier melt. In the 1940s, the level was 8% higher than the long-term average and 18 Watts per square metres above the levels of the past ten years. Calculated over the entire decade of the 1940s, this resulted in 4% more snow and ice melt compared with the past ten years.

Furthermore, the below-average melt rates at the measurement points during periods in which the glacier snouts were even advancing correlate with a phase of global dimming, between the 1950s and the 1980s.

Less snow fall and longer melt periods

The researchers arrived at their findings by calculating the daily melt rates with the aid of climate data and a temperature index model, based on the half-yearly measurements on the glaciers since 1914. These results were then compared with the long-term measurements of solar radiation in Davos.

Huss points out that the strong glacier melt in the 1940s puts into question the assumption that the rate of glacier decline in recent years "has never been seen before." "Nevertheless," says the glaciologist, "this should not lead people to conclude that the current period of global warming is not really as big of a problem for the glaciers as previously assumed." This is because it is not only the pace at which the Alpine glaciers are currently melting that is unusual, but the fact that this sharp decline has been unabated for 25 years now.

Another aspect to consider -- and this is evidenced by the researchers' findings -- is that temperature-based opposing mechanisms came into play around 30 years ago. These have led to a 12% decrease in the amount of precipitation that falls as snow as a percentage of total precipitation, accompanied by an increase of around one month in the length of the melt period ever since this time. Scientists warn that these effects could soon be matched by the lower level of solar radiation we have today compared with the 1940s.
Story Source:
Adapted from materials provided by ETH Zurich.

Journal Reference:
Huss et al. Strong Alpine glacier melt in the 1940s due to enhanced solar radiation. Geophysical Research Letters, 2009; 36 (23): L23501 DOI: 10.1029/2009GL040789

Nanoparticles To Combat Polluted Groundwater

Nanotechnology - Cleaning Up Our Water
Chemical Engineers Call On Nanoparticles To Combat Polluted Groundwater

Chemical engineers created nanoparticles out of gold and palladium to break down pollutants in groundwater. Adding the particles to groundwater converts dangerous contaminants like trichloroethylene into non-toxic compounds.

He's just 37 years old, but he's already making a difference in the world! A young engineer is creating small solutions to big problems.

We've seen it in the movies -- polluted drinking water is a health and environmental concern. In fact, right now, 30 states need to clean up their groundwater. "They've been designated by the EPA as being highly contaminated, and they've got to do something about the contaminated water," Michael Wong, Ph.D., a chemical engineer at Rice University in Houston, told Ivanhoe.

Dr. Wong is one of Smithsonian Magazine's America's Young Innovators … and for good reason. He's trying to come up with a way to use nanoparticles to clean up our water. "Water is not just H2O. Water has all sorts of stuff in it and the stuff we don't want, those are the things that can really hurt you," Dr. Wong explains.

He's using nanoparticles made out of gold and palladium -- a metal related to platinum -- to get rid of chemicals. One of the most common pollutants in United States groundwater is trichloroethylene, or TCE, a solvent used to degrease metals. And it can cause cancer.

"Our idea was, let's go ahead and break it down -- break it down into something that's safer," Dr. Wong says. "Safer chemicals that won't hurt your body and hurt the animals and the fish and what not."

Wong uses nanoparticles -- ten thousand times smaller than a human hair -- and hydrogen to break TCE into something non-toxic. "We are going to pump water through this guy here and the water is being pumped from the bottom up," Dr. Wong explains.

Glass beads will help to hold the nanoparticles in place. "Then clean water comes out," Dr. Wong says. Dr. Wong plans to test it at military sites first -- then move onto industrial sites and dry cleaning businesses. "I'd like to see our reactor do a really good job of getting rid of some of the contaminants," Dr. Wong says. Possibly, making our water and environment cleaner in the future. Dr. Wong says his reactor will be more efficient and cost less than the carbon reactors being used now.

WHAT IS HAZARDOUS WASTE? In the U.S., hazardous waste is defined as any discarded solid or liquid that is highly corrosive, toxic, reactive enough to release toxic fumes, or easily ignited. It can include solvents, pesticides, and spilled chemicals -- including acids, ammonia, chlorine bleach and other industrial cleaning agents -- as well as most heavy metals. Long-term exposure to hazardous waste can lead to chronic respiratory diseases such as asthma, damaged liver and kidneys, or cancer. Poisoning and chemical burns can result from contact with even small amounts of toxic chemical waste. Even brief exposure can cause headaches, dizziness, and nausea.

WHERE THAT GLASS OF WATER COMES FROM: Drinking water can come from either ground water sources, via wells, or surface water sources, such as rivers, lakes and streams. Most U.S. water systems in small and rural areas use a ground water source, while large metropolitan areas tend to rely on surface water. Causes of contamination can range from agricultural runoff to improper use of household chemicals.

SECONDARY STANDARDS: Even if your tap water meets the EPA's basic requirement for safe drinking water, some people still object to the taste, smell or appearance of their water. These are aesthetic concerns, however, and therefore fall under the EPA's voluntary secondary standards. Some tap water is drinkable, but may be temporarily clouded because of air bubbles, or have a chlorine taste. A bleachy taste can be improved by letting the water stand exposed to the air for a while.