Monday, 24 August 2015

One of the last hopes to defeat climate change just got debunked

Forests eat a lot of carbon dioxide — roughly a quarter of humanity's total yearly output. So when it comes to the future trajectory of climate change, the behavior of forests is one of the largest potential variables. If forests grow and thrive as the concentration of atmospheric carbon dioxide increases (thus providing them more potential food), then climate change could be strongly mitigated.

On the other hand, if changing weather patterns fueled by global warming kill them off instead, they could release much of the carbon contained in their wood, as they die and rot. The potential range is enormous, says climatologist Dr. William Anderegg, associate professor at the University of Utah and lead author of a new paper in Science on trees and drought. By 2100, world forests could go from a net carbon sink of roughly six billion metric tons per year, to a net source of about the same size.

Anderegg's paper is about hysteresis in forests, a term that might be familiar from economics. Climate change will likely cause increased drought as it gets worse, and just as long spells of unemployment can have lingering effects on those who suffer it, "droughts have lasting effects on ecosystems of forests," says Anderegg. Forests grow slower during droughts, of course, but they also grow slower after the drought is over. In the first year after a drought, Anderegg and his team found trees grew an average of about 9 percent slower; in the second year about 5 percent. They estimate this effect could result in a 3 percent decline in the total carbon stored across their sample size by 2100.

The study also reveals a significant weakness with most major climate models. "Most models don't have mechanisms for drought stress," says Anderegg. Instead, they have a light-switch model, where drought has negative effects while it's happening, but they vanish instantly when the drought is over. He and his colleagues are working to incorporate their drought results into climate models. It's a tricky task, since the models are already very complicated and computationally heavy, but they are close to developing a streamlined technique that can capture most of the measured effects, he says.

This figure shows the overall average effect of drought across the sample size on the right, the difference between wet and arid forests in the middle, and the difference between Pinaceae (the pine tree family) and Fagaceae (that of beech and oaks) on the right:

However, one must be careful not to over-generalize at this point. Anderegg and his team mostly studied semi-arid forests in North America and Europe. Tropical and boreal forests — which make a far greater proportion of forests overall — were largely not studied.

The reason they didn't is simply measurement challenge. Tropical forests, in particular, are dramatically more difficult to study, because most of the trees do not create rings as they grow. (Since the tropics typically don't have regular seasons, growth is basically even and constant.) Without rings, then one is forced to rely on foliage studies from satellites or aerial photography, which are reasonably easy to do but don't contain the whole history of each tree. Or, one can go into the forest and take regular manual measurements of tree size, which is similarly missing the history, and is also enormously labor-intensive. (Not to mention the fact that many tropical regions, like the Democratic Republic of the Congo, are chronically unstable with poor infrastructure.)

However, this study is still suggestive. The 3 percent figure given above is "almost certainly an underestimate," says Anderegg. Drought does not just weaken trees, it also kills them. Studies on recent drought in the Amazon and Borneo found significant mortality, particularly among the largest trees. More recently, scientists have found a slowing rate of carbon uptake in the Amazon.

So in context, Anderegg's paper is a reasonably strong piece of evidence pointing towards the hypothesis that forests will not be a net carbon sink. Best not to pin our hopes for climate change on future mega-forests.

 
#science 
 » see original post http://theweek.com/articles/569733/last-hopes-defeat-climate-change-just-got-debunked

Ferrolic: A Clock with a Liquid Face Powered by Magnetism

clock-1

Way back in 2000 I downloaded a screensaver designed by Yugo Nakamura called DropClock that tied in with your systems’ internal time to create a functional clock face depicting Helvetica numbers dropping into water in slow motion. It was mesmerizing to watch and I kept it running for years. Designer Zelf Koelman took the idea of merging time and liquid a step further by creating Ferrolic, a self-contained clock that literally displays time with liquid. It’s almost exactly what would happen if a digital clock and a lava lamp had a baby.

Ferrolic utilizes ferrofluid—a liquid that becomes strongly magnetized in the presence of a magnetic field—to display recognizable shapes in response to magnets embedded inside the clock’s aluminum frame. The moving blobs look almost alive, a fact not lost on Koelman who refers to them as “creatures.” He shares:

Ferrolic was designed from a strong fascination for the magical material Ferro Fluid. The natural dynamics of this fluid makes that this display bridges the gap between everyday digital screens and tangible reality.

Because the fluid behaves in a unpredictable way, it is possible to give the bodies perceived in the Ferrolic display a strong reference to living creatures. It is this lively hood that enables Ferrolic to show a meaningful narrative like for instance having the creatures play tag. In addition the natural flow of the material, it can be used to form recognisable shapes and characters. Ferrolic uses these both layers in parallel in order to display scenes and transitions in an poetic, almost dance like, choreographed way.

The clocks are a bit of a prototype so far, only 24 of the devices are available at a price of about $8,000 each, making it much more of a limited edition art piece than a consumer-grade alarm clock. You can learn more here. (via Boing Boing, Fast Company)

 
#funandrandom 
 » see original post http://feedproxy.google.com/~r/colossal/~3/XF2slAcQldk/

A Hypnotic Infinite Model Train Loop that Travels Rapidly in Either Direction

Model train enthusiast James Risner decided to turn several toy locomotive sets into a contemporary kinetic art installation of sorts by creating an infinite loop. The seven linked trains can travel forward or backward at surprisingly quick speed, creating a hypnotic spiral of of motion. I wonder if this could be scaled to a Metropolis II level? (via Laughing Squid)

 
#funandrandom 
 » see original post http://feedproxy.google.com/~r/colossal/~3/NCWeLtyMEBQ/