Musings, politics and environmental issues

Archive for October, 2013

Promising new method for producing hydrogen fuel

Scientists in California have developed a novel device that harnesses sun and sewage to produce hydrogen fuel, at the same time as improving the efficiency of wastewater treatment. The device is made up of two components: a microbial fuel cell (MFC) and a kind of solar cell called a photoelectrochemical cell (PEC). In the MFC component, bacteria degrade organic matter in the wastewater, generating electricity in the process. The biologically generated electricity is delivered to the PEC component to assist the solar-powered splitting of water (electrolysis) that generates hydrogen and oxygen.

Both types of fuel cells can produce electricity on their own but are expensive when used on a large scale as additional electricity is required. In comparison, the hybrid solar-microbial device is self-driven and self-sustained, because the combined energy from the organic matter (harvested by the MFC) and sunlight (captured by the PEC) is sufficient to drive electrolysis of water.

A press release from the University of California describes additional technical details. But I think the technique is worth circulating more widely, as hydrogen production is often criticised for being energy-intensive – and this looks like it won’t be.


Majority of urban dwellers subject to carcinogenic air pollution

The European Environment Agency has just released a report that is quite horrifying: around 90% of residents in the EU/EEA are exposed to one or more of the most damaging air pollutants – particulate matter and ozone (O3) – although levels of lead (Pb), sulphur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide (CO) have decreased.  Here is an excerpt of the main findings:

Emissions of the main air pollutants in Europe declined in the period 2002–2011. This resulted in improved air quality across the region — at least with respect to certain pollutants. Certain individual sectors have seen emissions of some pollutants increase during this period. For example, PM emissions from fuel combustion in the commercial, institutional and household sector, has increased by around 7 % since 2002. This sector is now the most important contributor to total European Union PM emissions … However, due to the complex links between emissions and air quality (which include emission heights, chemical transformations, reactions to sunlight, additional natural and hemispheric contributions and the impact of weather and topography), emission reductions do not always produce a corresponding drop in atmospheric concentrations, especially for PM and O3. For example, while reductions of O3 forming substances (O3 precursor gases) have been substantial in Europe, ozone concentrations (in relation to the target value for the protection of health) have generally decreased slowly but have increased in places between 2002 and 2011.

The report goes on to explain that:

In terms of potential to harm human health, PM poses the greatest risk, as it penetrates into sensitive regions of the respiratory system and can lead to health problems and premature mortality. PM in the air has many sources and is a complex heterogeneous mixture. The sizes and chemical composition of this mixture can change in time and space, depending on emission sources and atmospheric and weather conditions.
PM in the atmosphere originates from:

  • primary particles emitted directly;
  • secondary particles produced as a result of chemical reactions involving PM forming (precursor) gases after their emission: SO2, NOX, NH3 and non-methane volatile organic compounds (NMVOC). When these gases react, they produce PM.

The size of PM is expressed in micrometers. The largest particles of concern are 10 microns in diameter or smaller (PM10). But the group of particles of most concern is 2.5 microns in diameter or smaller (PM2.5). Some of these are small enough to pass from the lung into the bloodstream … The health effects of PM are caused after their inhalation and penetration into the lungs and blood stream, leading to adverse effects in the respiratory, cardiovascular, immune, and neural systems. A fraction of ultrafine particles (with a diameter less than 0.1 microns) may even enter the brain directly through the nose.

In urban areas in the EU, 97-98% of the population is exposed to levels of ozone over WHO guidelines. With PM2.5 and PM 10, 91-96% and 85-88% of the population is exposed to levels above the WHO recommended guidelines respectively. A high proportion of the population, 76-94%, is also exposed to one of the damaging poly-aromatic hydrocarbons, benzo(a)pyrene (BaP), which is a known carcinogen.

Yesterday, just two days after the EEA report, the WHO announced that outdoor air pollution is a leading environmental cause of cancer deaths, in particular lung cancer but also bladder cancer. They evaluated PM separately and classified that too as carcinogenic. They say that the main sources of air pollution are transportation, stationary power generation, industrial and agricultural emissions, and residential heating and cooking.

The EEA also covered the effects of air pollution on climate and ecosystems.

Climate departure and climate change

A paper that details worrying tends about climate change has just been published in Nature. Basically, the authors say that if greenhouse gas emissions continue to increase as they have done in  past decades, very soon  – even as early as 2020 for some places on the equator such as Manokwari in Indonesia – the coldest year in any particular city or region will be hotter than the hottest year ever in its past, “past” here being defined as 1860 to 2005. The authors of the paper call this “climate departure”.

The research was carried out by scientists in Hawaii, who studied massive amounts of data, weather observations and computer models in 263 cities. Countries on the equator – which have in general done very little to hasten global warming – will be affected first, and other cities will follow according to their distance from the equator. Thus New York will experience its climate departure in 2047, Cape Town  in 2038 and Reykjavik in 2066. As the furthest away, Anchorage in Alaska will climate depart in 2071. There is a five-year standard deviation on the figures and if greenhouse gas emissions are reduced, it will take about 20-25 years longer for each city to reach its climate departure point.

The scientists, headed by Camilo Mora,  also looked at other variables including ocean acidity, which they found to be very disturbing. Give or take three years, in 2008 ocean acidity had already exceeded its historical bounds.

Food for thought.

“Immediate promises” in the political sense

For the first few months of their political comeback, the ministers of the Icelandic Independent Party/Progressive Party coalition – none of whom had previously been in a ministerial position – frequently said something which was retracted the next day by someone else, usually the PM, Sigmundur David Gunnlaugsson. For instance, Agriculture, Fisheries and Environment Minister Sigurdur Ingi Johannsson’s remark about the government doing away with the environment ministry completely was corrected next day by SDG.

Now the draft budget for next year has been released and the opposition is angry, especially about the plan to charge patients a (albeit modest) fee for a hospital stay, which is on the cards. “Oh, but we don’t mean everyone will have to pay,” said the health minister, Kristjan Thor Juliusson, a few days later.  The previous government had allocated a special grant for hospital equipment for this year, but that no longer exists.

Icelanders remember well the PP’s promise pre-election of vastly increased sums for the beleaguered national university hospital in Reykjavik, Landspitalinn, not to mention immediate help for home-owners who are often having to pay more in loans than their property is worth. But now Vigdis Hauksdottir, a PP member who is chair of the Althingi’s finance committee and part of the committee that was tasked with finding our how budget cuts could be made, has come up with a new definition of “immediate”. Because a government is elected for four years, “immediate” could be defined somewhat flexibly. she says.

So there you have it.