Good news about global warming, at last!

I normally try to write about drinking water, but I stumbled across some good news about global warming. It's a bit bizarre, but the take home message is that we could be so much worse off, apparently.

Global warming by production of greenhouse gases, especially carbon dioxide and methane, has lead to concerns over the survival of the planet. Actually, it's the survival of humans on this planet that is the real issue - the Earth will muddle along without us very well, and even probably do better without our polluting ways!

We have just completed a string of ten relatively stable years, 2000-2009, with respect to Earth's temperatures, that has been partly attributed to a reduction in water vapour in parts of the middle atmosphere, the Stratosphere, according to an article published online at the journal Science this week. Water vapour absorbs solar energy and then re-emits it as heat down into the lower Troposphere and the Earth below, thus acting as a heat-trap or 'greenhouse'. This fall in concentration of water vapour in the Stratosphere (for reason(s) unknown) has slowed the rate of Earth's warming by a staggering 25%. So that's 25% slow-down from a 10% change in water vapour, 10 miles over our heads, over the past 10 years. Not bad.

Compare this to 1980-2000, when an increase in water vapour in the Stratosphere sped up the rate of warming. This was due to higher rates of methane emission; methane oxidises into water vapour and carbon dioxide, which trap heat:


NB: not all carbon dioxide comes from methane, the majority of it comes directly from our activities.

It has long been known that water vapour in the lower Troposphere, the layer nearest the Earth, amplifies the effect of greenhouse gas emission, but this finding of its effects when present in the Stratosphere is novel.

Good news as far as it goes, but it doesn't let us off the hook there is no doubt that the Earth is still warming, its just not doing it as fast as we used to see.

Clean water shortages in wake of Haitian earthquake

The earthquake in Haiti on 12th January 2010 has claimed the lives of up to 200,000 people and left hundreds of thousands more living on the streets of Port-au-Prince. With up to 3 million affected by the 7.0-magnitude quake, the country is understandably struggling to cope. Aftershocks are a very real danger: one of magnitude 4.5 severely hampered resue efforts for a time in parts of the city.

Help is now needed in providing enough clean drinking water for the survivors to prevent dehydration and outbreak of waterborne diseases. Survivors are camping under plastic sheets without proper food, drinking water or medical supplies. Water is available for sale on the streets at inflated prices and aid agencies are deperately trying to fill the gap between demand and supply. Desalination equipment is en route from the US by sea to provide 25,000 litres of water a day to supplement the 35,000 litres per day being produced by the aircraft carrier USS Carl Vinson, that is already there. International aid is also arriving by air, although the airport at Port-au-Prince is overwhelmed with relief flights trying to land. Some bottled water has been shipped but water purification systems will provide the most efficient and cost-effective long-term solution. Distributing this water to the population is proving difficult as the devastation has cut transport communications and bottlenecks have been reported. Camps are to be set up for shelter, water and latrines and will be a focus for distribution of supplies to survivors and aid-workers alike.

The British public has already donated more than £23 million to the DEC, the Disasters Emergency Committee, an umbrella organisation for 13 humanitarian aid agencies. You can donate by going to their website at www.dec.org.uk and giving what you can afford.

Water is life. Help save a life today

Over-enthusastic chlorine filtration kills hotel visitor

Whole house chlorine filtration sounds a great way to get rid of the nasty-tasting chlorine: by removing the chlorine from the mains water supply as it enters the property, not only can you drink the water from any tap, but also all baths and showers don't give off that 'swimming-pool' smell of chlorine given off as you bathe and can help reduce skin irritation.

As I said, sounds great, but what are the potential pitfalls? Well, the reason we have a chlorinated mains water supply is that chlorine treatment helps prevent cholera, Legionnaire's disease and other horrible water-borne bacteria. The chlorine is present to help deliver safe drinkable water to our taps - it's like the plastic bag a loaf of bread comes in. The plastic bag helps keep the bread fresh on the shop's shelf, protects it as we carry it home, and helps preserve its freshness further at home as we eat it - but we don't eat the plastic bag. Chlorine in mains water is necessary for safe delivery to our taps, but we don't need to drink it...

So what went wrong at that hotel in Miami where the chlorine-treatment system installed has been blamed on the death of one tourist and the sickness of more? Well, it seems that Legionella bacteria was able to grow in the hotel's water supply, so that some guests contracted Legionnaire's disease, a rare form of pneumonia caught by contaminated water droplets entering the lungs which can be fatal in up to 1/3 of sufferers. The water droplets enter the lungs usually from drinking liquid (tap water) or inhaling water vapour water during a bath or shower. The hotel installed the system to enhance the quality of its drinking water for guests, but the mistake was that the system was too good at its job and heavily de-chlorinated water was allowed to stand in the waterpipes serving the hotel, giving bacteria chance to colonise.

The best way to dechlorinate tap water is to have a filter fitted just before it exits the tap or showerhead so the water pipes in a property only have chlorinated water standing in them and bacteria won't accumulate. Certainly, large buildings that may maintain a cold water header tank should not have a whole-house filtration system, as the bacteria would be very happy in such tanks - and human users would suffer the consequences. Through careful design and siting of tap water filtration systems, these remain the most economic, healthiest and greenest form of delivering pleasant drinking water to users compared to bottled water systems.

The Just Water Now mains-water filtration products are fitted at the 'point-of-use', just where the water is drawn off by a user, so that there is minimal chance of contamination. e.g the JWN Unit Filter is a simple cold-water filtration system that fits existing taps. We also ensure that a non-return valve is fitted to prevent backflow of dechlorinated water back into the distribution pipes if a fault developed.


Visit www.justwaternow.com to find out more.

My thanks to Bill Burton for the 'loaf of bread' analogy.