Climate News: World’s Most Potent Greenhouse Gas Found

NASA_global_warming_predFor over a century now, scientists have understood the crucial link that lies between greenhouse gases and the effect known as “Global Warming”. For decades, scientists have been focused on the role played by carbon dioxide and methane gas, the two principle polluters that are tied to human behavior and the consequences of our activities.

But now, a long-lived greenhouse gas, more potent than any other, has been discovered in the upper atmosphere by chemists at the University of Toronto. It’s known as Perfluorotributylamine (PFTBA), a gas that has a radiative efficiency of 0.86 – which is one measure of a chemical’s effectiveness at warming the climate (expressed in parts per million).

upper_atmosphereAt present, the biggest contributor to climate change is carbon dioxide, mainly because its concentrations are so high — 393.1 parts per million in 2012 and growing, thanks to human activity. However, many other gases contribute to this trend – such as nitrogen trifluoride and various chloroflurocarbons (CFCs) – but are less involved in the overall warming effect because their concentrations are lower.

According to the research article, which appeared in a recent issue of Geophysics Research Letters, the concentrations of PFTBA are very small — about 0.18 parts per trillion by volume in the atmosphere (at least in Toronto, where it was detected). But even though the overall contribution of PFTBA is comparatively small, its effect is “on the same scale as some of the gases that the monitoring community is aware of.”

Toronto Skyline With SmogAccording to 3M, a producer of PFTBA, the chemical has been sold for more than 30 years for the purpose of cooling semiconductor processing equipment and specialized military equipment, much in the same way that CFCs have been used. It is effective at transferring heat away from electronic components, and is stable, non-flammable, non-toxic, and doesn’t conduct electricity.

The chemical has an average lifespan of about 500 years in the lower atmosphere, and also like CFC’s, it has long been known to have the potential to cause damage to the ozone layer. But up until now its ability to trap heat in the atmosphere had not been measured, nor had it been detected in the atmosphere. The reason PFTBA is so potent compared to other gases is that it absorbs heat that would normally escape from the atmosphere.

electromagnetic-spectrumHeat, or infrared radiation comes, in different colors, and each greenhouse gas is only able to absorb certain colors of heat. PFTBA is different in that it manages to absorb colors that other greenhouse gases don’t. It was after some was discovered on the university grounds by Professor Scott Mabury that his team began to consider whether any had made it into the atmosphere as well.

Shortly thereafter, they conducted a series of tests to measure the radiative efficiency of the chemical and then began looking for samples of it in the air. This involved deploying air pumps to three locations – including the University of Toronto campus, Mt. Pleasant Cemetery and Woodbine Beach. The samples were then condensed and concentrated, and the PFTBA separated by weight.

airpollution1The end result was that PFTBA was found in all samples, including those upwind from the University of Toronto, suggesting that it wasn’t just coming from the chemistry building. However, the measurements were local and therefore not representative of the global average concentrations of the chemical. Still, its discovery is an indication that dangers might exist.

According to Angela Hong, a PhD student at the UofT department of chemistry and the lead author of the paper, this danger lies in the combined effect PFTBA could have alongside other gases:

If you’re suddenly going to add a greenhouse gas and it absorbs in that region. it’s going to be very potent.

Its effect is far more intense if its effect per molecule is considered, since it is about 15 times heavier than carbon dioxide. What’s more, PFTBA survives hundreds of years in the atmosphere, which means its effects are long-lasting. Fortunately, its use has been regulated under a U.S. Environmental Protection Agency program that promotes alternatives to chemicals that deplete the ozone layer.

pftba-toronto-537x402In addition, chemicals that deplete the ozone layer are recognized by the Kyoto Protocols. As such, it should be an easy matter (from a legal standpoint anyway) to legislate against its continued use. As 3M indicated in a recent press statement:

That regulation stipulates that PFCs [the class of chemical that PFTBA belongs to] should be used only where there are no other alternatives on the basis of performance and safety. 3M adheres to that policy globally.

It added that the company “has worked to limit the use of these materials to non-emissive applications” and emphasized that the concentration of PFTBA found in the atmosphere is very low.

????????????????Nevertheless, this represents good news and bad news when it comes to the ongoing issue of Climate Change. On the one hand, early detection like this is a good way of ensuring that gases that contribute to the problem can be identified and brought under control before they become a problem. On the other, it shows us that when it comes to warming, there are more culprits than previously expected to contributing to it.

According to the most recent IPCC report, which was filed in 2012, the likelihood of us reaching a critical tipping point – i.e. the point of no return with warming – this century is highly unlikely. But that still leaves plenty of room for the problem to get worse before it gets better. One can only hope we get our acts together before it’s too late.

Sources: cbc.ca, IO9

The Future is Here: The Invisibility Cloak!

quantum-stealth-fieldInvisibility cloaks have long been considered the next frontier of modern warfare. With stealth aircraft, stealth ships and even stealth tanks in service or on well on their way, it seems like the time is ripe for a stealth soldier. But difficulties remains. Whereas cloaking planes, ships and tanks is a matter of simply coating them in materials that can obscure them from radar and thermal imagine, soldiers need camouflage that can move, bend and flex with them.

In recent years, the efforts to produce a working “invisibility cloak” have born considerable fruit. And while most of these took the form of large, cumbersome, desk-mounted constructions that were more of a proof of concept for the material being tested, they did demonstrate that the technology itself worked. This was certainly true of the “cloak” which was created by scientists at Duke University in November of 2012.

INVISIBILITY-CLOAKAnd then came news the following month that a Canadian company named Hyperstealth developed a material that renders the wearer “completely invisible by bending light waves around the target.” Known as “Quantum Stealth”, this true cloak is an apparent follow-up to their SmartCamo – a material that could reportedly adjust its camouflage markings to match its surroundings – that was released at the International Camouflage Symposium in 2010.

Unfortunately, due to security reasons, little was ever known about SmartCamo other than its reported abilities. The same holds true for Quantum Stealth, which the company has been forced to remain clandestine about due the demands of the US Army, to whom they are contracted. So until such time as it enters widespread use, the details and inner workings of the technology will remain inaccessible.

invisibility_cloak1Luckily, the University of Texas in Austin is under no such constrictions, and it is from them that the latest and greatest news comes. In addition to being composed of conventional materials, their new cloak measures a mere 166 micrometers thick and is capable of obscuring an object from multiple directions at once. And though it may not be able to render a soldier truly invisible, it does render them all but invisible to radar detection, which is the intent here.

The fabrication process involved placing a 66µm-thick sheet of carbon (or a metascreen) onto a a 100µm-thick sheet of flexible polycarbonate. The copper is patterned specifically so that the scattered light from the cloak and the cloaked object cancel each other out. This flexible sheet also allows the cloak to conform to the shape of the object, or person, and provides cloaking from microwave radiation from all directions.

invisibility_cloak_uoftNow here’s where things get literal. The researchers responsible for this breakthrough have indicated that, in theory, this cloak could be used to cloak visible light as well. After all, microwaves, infrared and visible light are all physically identical; they are just waves that oscillate at different frequencies. And their design would be more capable of doing this than any cloak composed of metamaterials.

Still, size and scale are still an issue. Whereas their new patterned material scattering technique is capable of hiding an object from multiple directions, it also inversely scales with wavelength. That means that it is only capable of hiding micrometer-scale objects from 400-800THz of visible light. Still, this is exciting news and a step in the right direction!

Before we know it, stealth troopers could be marching all over the planet, invisible to the naked eye and any means of radar detection… Holy crap, what a scary thought! Is it too late to rethink this technology?

future_soldierSource: Extremetech.com, (2)