SkyTruth

In case you haven't caught up with it yet, SkyTruth is going to create something of a revolution - a tool for actually seeing what is happening to our world in real time and providing the ability to see  changes over time.  I first heard about it from Michael Field of Fairfax on New Zealand National Radio on Friday the 14th of February, 2014.  He kindly sent me a transcript of the guts of what was talked about so rather than writing it out again, I have pasted it below.  It has been a long time coming since the beginning of the Satellite era but here it is finally. It is worth noting that you can't access it at present because the information is proprietary but this will change some time this year with the launch of a new satellite.

Shock at the scale of fishing in South Pacific

Michael Field

Fleets of sophisticated Chinese and Spanish fishing boats working the edge of New Zealand’s exclusive economic zone (EEZ) have been exposed by an American volunteer group whose work is creating a revolution to the environmental movement.

Fishing boats create picket fence lines on the edge of the EEZ around places like the Kermadecs and off East Cape, taking bluefin tuna, swordfish and orange roughy.

‘‘Most people would be gobsmacked by what we are finding,’’ geologist John Amos said from Shepherdstown, West Virginia, (pop. 805) where the group SkyTruth operating out of an office behind a draper’s shop.

They’ve also spotted an unusual 34-year-old Cambodian flagged tuna boat, Gral, leaving Suva, Fiji, and making straight for New Zealand’s Raoul Island despite having no licence, permissions or complying with normally strict quarantine procedures.

SkyTruth has been commissioned by the US based US$792 million (NZ$972 million) asset rich Pew Charitable Trusts to monitor what is happening around the Kermadecs, an archipelago 1100 km north of Auckland, home to one of the world’s most diverse marine life.

Pew has supported the Kermadec Initiative which is calling for a 620,000 sq km ocean sanctuary from the existing island reserves out to the EEZ.

SkyTruth use Automatic Identification System (AIS) satellite data transmitted from ships and satellite radar imagery to detect fishing boats that turn off or do not use AIS. 

Amos says they find many vessels ‘‘fishing-the-line’’ to catch valuable fish before the stock gets into New Zealand waters.

‘‘Not just around New Zealand, but also in Chilean waters, we see Chinese, Ukrainian and Spanish flag vessel fishing right up to the line.... You see this concentration of fishing effort around the line and you wonder how many of these migratory fish even make it through.’’

‘‘It is like a picket fence of fishermen.’’ Amos said they are producing a South Pacific map that will show the cumulative fishing that has gone on over a 12-month period.

‘‘That is the kind of thing we can do now,’’ he says, adding people will be shocked by what they see. 

New Zealand makes some money off the Spanish.

Last November two of the armada ships, Carmen Tere and Artico, were serviced in Whangarei. Their Indonesian crews complained of poor treatment at the time.

SkyTruth in the last couple of weeks has spotted Carmen Tere working a line off East Cape and Artico is on picket duty at the Kermadecs. A fleet of four Spanish ships is gathered in an area of orange roughy fishing grounds.

Most of their catches are taken to Papeete, or transhipped at sea.

With a new European Space Agency satellite, Sentinel 1, in orbit next month, SkyTruth expect a ‘‘stream of free radar imagery....

‘‘Clouds of data seems to be what we humans are good at producing these days, and using that is for good purposes.’’

It can identify problems in the EEZs and shows the sheer persistence of the fishing industry.

‘‘There is no place these guys don’t go.’’

SkyTruth first came to world attention when the White House used it to work out the scale of 2010’s Deepwater Horizon oil spill in the Gulf of Mexico.

Amos, 50, recently cataloguing the number and size of fracking operations, is a folk hero in the US.

‘‘You can track anything in the world from anywhere in the world,’’ Amos told the Washington Post last year.

‘‘That’s the real revolution.’’

SkyTruth’s technology edge was revealed when a 498 ton ‘‘fish transporter’’ Gral pulled into Suva on January 17.

Owned by South Korea’s ‘‘Aururoa Shipping’’ it had been called Arche until December – and before that the tuna longliner Gaia, Oryong No 332 and Sam Song No 507.

On January 20 it sailed out of Suva and made directly for Raoul, arriving at 2.55am on January 23.

Conservation Minister Nick Smith said he had not been briefed on Gral and referred questions to officials who could not provide information on it.

The Ministry of Primary Industries said ‘‘it had broken down and was undertaking repairs’’.

Amos dismisses the MPI line.

‘‘It appears that the moment they left from Fiji, (Raoul) was the destination.’’

Fuel was expensive and from watching marine traffic SkyTruth saw ships always went the straightest line possible.

A Tauranga ship, Claymore II, under charter to the Department of Conservation, earlier this month found Gral anchored in a bay they would use.

Its owner, Nigel Jolly, said before they left New Zealand, DOC rules required divers inspect the hull for marine life and a quarantine dog was run through.

‘‘After all those precautions we get a permit to go there, but if fishing boat or a visiting yacht seeks shelter at Raoul Island, no matter if it is a reserve, the law of the sea says it has a right.’’

They never found out what Gral was doing.

Bronwen Golder, director of Pew’s Kermadec Initiative, says SkyTruth under-scores the vulnerability of the area and the need for a marine sanctuary.

‘‘What this daily tracking shows is that there is constant international fishing activity just outside of New Zealand’s EEZ over extended periods and in fleets such as the Spanish,’’ she said.

SkyTruth has tracked Gral out of New Zealand’s EEZ and headed toward French Polynesia.

On the high seas late last week it rendezvoused with a Russian fishing boat, the 1137 ton Palmer which had switched its AIS off until the meeting.

On Saturday they remain within five kilometres of each other.

10 february 2014

Natural Selection and Evolution

This blog was triggered by an item I heard on National Radio here in New Zealand.  An ornithologist was talking about banding birds and how they band the common house sparrow.  Apparently they band them, both to learn about sparrows but also to give their people practice in banding small birds before they tackle rare and endangered species.  In the talk, he mentioned that with multiple clutches, a pair of sparrows can easily produce 20 young each summer season.  He also mentioned that the natural life span of a sparrow is about 10 years.

This got me to thinking how quickly a population of sparrows could grow.  Start with one pair and by the end of the year you have 11 pair*.  Next year these 11 pairs breed and you have 121 pairs.  In the third year these breed and you have 1331 pairs.  Let's go to 10 years which is the life span of the first pair.  You get up to `259,374,246 pairs.  Over half a billion individual sparrows in a decade.

*The 10 pair they produce plus themselves.

Now clearly, the only time that such an expansion could occur would be when the sparrow was introduced into a new environment in which there was abundant food, no natural diseases, no predators and abundant nesting sites.  Even then, this sort of expansion would be unlikely to continue for more than a few years.   No matter how large the food supply, the sparrows would soon exhaust it.

We actually observe that in any area where sparrows have been extant for a while, the sparrow population remains pretty much the same.  There are good sparrow years and bad sparrow years but overall the population varies around a  mean.  Let's assume for the sake of the argument that with the various factors working on the population, the average life span of the first successful breeding pair is actually 5 years.  We are being pretty generous here.  What this means  for the successful breeding pair, is that on average,  of the 100 babies that they produce over their life time (at 20 per year for 5 years), only one pair will survive.  If more survived the population would grow, if less, it would shrink.  That is a 98% death rate or more to the point, 98% don't get to pass on their genes to the next generation*.  This is natural selection.  It is huge.  Talk about survival of the fittest.  Sure some will succumb to random accidents that have nothing to do with their fitness but consider the sparrows that will survive to pass on their characteristics.  A surviving sparrow will likely have:

*In evolutionary terms, not passing on your genes is 'death'.

*Better disease resistance
*A beak that is adapted to cracking the seeds that exists in the region.
*An ability to utilize other food sources
*The same colouring as its fellows so that it doesn't attract the attention of Kestrils
*A great ability to choose safe nest building sites and to build good nests
*A very strong inclination to look after it's young.
*A flexibility in choosing nesting material and, nowadays,  being able to utilize human products.

and on and on the list goes.

Here we come to one of the main characteristics of Natural Selection.  Once an animal is pretty well adapted to it's environment, and the environment is unchanging, Natural Selection has much more to do with keeping the animal the same than it has to do with producing new varieties.  Most variations will be less successful than the standard and with the huge reaping of the young, only the best will make it.  Paliantologists have been puzzled by punctuated evolution*.   Here, at least, is the explanation for the  opposite; the long periods in which no apparent evolution occurs.  Let's look at predation for example.

*Punctuated evolution - An animal or plant staying the same for a long time and then suddenly radiating into a bunch of new forms.

The Kestrel is known colloquially as the sparrow hawk for a very good reason.  It hunts sparrows and it hunts them on the wing. Our Kestrel is stooping on a flock of sparrows.  One of them is white.  How much easier it is for the Kestrel to keep it's eye on one individual bird if it is different.  If it keeps shifting it's focus from bird to bird, it is always chasing a fresh bird rather than the one it initially locked on to.  If all the sparrows were white then a dun coloured bird would be at a disadvantage but as long as the majority are dun, the white one will have a very limited life.  Think of Lions and Zebra's as another example. 

However if one beneficial mutation does occur which doesn't have a down-side, you can see how fast it could spread through the population as the carriers of this new gene out-compete the standard sparrow.

It's an interesting thought that the greatest enemy to a sparrow is another sparrow. We see the population staying more or less the same so  this enmity between sparrows is not apparent to our eye.  One sparrow does not predate another sparrow.  However they compete for exactly the same resources.  They compete for nesting sites, food, mates and so forth.   The successful sparrow passes on his genes, the unsuccessful one does not.

Even more so, if a huge number of ecological nitches are left empty after, say, a meteor strike such as occurred 65m years ago, evolution can go wild.  And as each new variety changes, it changes the environment for a range of species around it.  An environment is not only the trees and bushes and physical features where you live.  It also includes all the other animals in the vicinity that you prey on, the animals that prey on you and those that you compete with for food.There is an arms race such as occurs with humans during a protracted war.  Look at all the developments in a wide range of fields that occurred because of the first and second world wars.  Not only did we have the classic better shell, better armour, better shell better armour but also developments in medicine, radar, communication, aircraft technology and so forth.  The same happens amongst the animals and plants when they face a new environment. If they are sufficiently adapted to survive at all, they then undergo rapid evolution which better suits them to the new environment.  Darwin's finches are one of the best documented examples of this process.

Now let's assume that blown on the wind or brought on the feathers of a migratory bird, some seeds arrive.  These seeds are for a plant that has seeds that our sparrow could eat but only with a stronger beak.  The plant flourishes because nothing is eating it and eventually, with genetic variability, a sparrow is born that can use these seeds.  With a new food source that only he can utilize, his survival potential and his potential to produce surviving offspring who can also use this new food source is huge.  Remember, the potential to increase your population if there is a new food supply is huge.  The population of this new model expands very rapidly and since it competes with the older variety in every other aspect of its life, it rapidly replaces the original type.  All we notice is that the beaks of collected birds of this species increase in size over a period and we puzzle over why.  In fact there has been a huge unobserved mortality amongst the standard variety.

We come now to the question of how much natural variability is available for natural selection to work on.  We study various populations over our life time and through the museum and even the fossil record and rarely see an animal that varies much from the norm so we assume that "sports" are rare.  We, however, only have to look at our domestic plants and animals to realize how wrong we are.  Look at all the dog breeds we have.  We replaced selection by nature with human selection and we can keep alive whichever varieties we desire.  In a few thousand years, starting with the wolf, we have produced all the breeds of dogs you see today.  The wolf hasn't changed much over this period.  He is constrained by natural selection to stay in the already well adapted form that he has had for thousands of years.  Our conclusion??

Given a change in the environment that favors a different type of animal or plant, evolution can occur explosively.  There will be lots of sports to choose from and the selection process is relentless.  The expansion potential for an animal or plant that can exploit a new opportunity is vast. This may be the explanation of what geneticists call punctuated evolution.  It is most likely to occur when something has changed an environment.  This can include:

*A disease or human intervention that wipes out a species, especially a key species such as the beaver, or the honey bee.

*A cataclysm such as a large meteorite or mega volcano that wipes out the animals of an area.  But note here that some pretty large events can occur with no apparent effect on the make up of plants and animals of an area.  As long as some populations of each component of the ecology still exist, then after a bit of argy bardgy, they will pretty well re-establish the original ecology. 

*The introduction of a new species of plant or animal into an environment.  This can be causes geologically, when a continent such as India bumps into the under side of Asia (55m years ago) or when man brings a new animal or plant to an island or continent where it didn't exist before.

Something curious that emerges from this, very incomplete list, is that man can  have (and has had) a much larger effect than a major meteorite strike or a mega volcano erupting.

On a  time scale, much shorter than geological,  Natural selection / evolution has huge potential to create new varieties given the right set of circumstances.  In a well established environment, thought, it mainly works to keep everything the same.

The destruction of Planet Earth

Sorry, I just wanted to get your attention.  There is no way (well almost no way) we could destroy Earth*.  In the words of my second favourite comedian**, George Carlin, the world will be just fine.  We may not be here but the world will be hunki dori.

* I've included a way at the end of this blog but it is pretty far "out there".
**My favourite is Bill Maher

It's true we may bring nature to a state where there is no animal larger than a cat remaining on the surface but evolution will refill all these lovely empty ecological nitches and it will do it surprisingly fast  in a wild flurry of evolution.  In one or two million years, we won't recognize the place???

The first people who arrived on any uninhabited  island or continent eliminated a huge range of megafauna.  Most of it was done within a few hundred years.  Then when European man arrived with his modern technology, he destroyed and is still destroying whole ecosystems.

When Europeans arrived in, for instance, North America, Australia and New Zealand, the fauna they saw was but a pale remnant of what was there before the first humans arrived.  The first humans had wiped out anything they could eat.  Then European man got busy, trying, quite successfully, to eliminate even this pitiful remnant and doing his best, as well, to eliminate the first people.    Who eliminate who often seemed to depend on who had the best armoury of diseases that they, but not the other side, were immune to but that's another story.

About the only area that has retained some semblance of her megafauna is Africa and only because animals  evolved escape capabilities as humans improved their hunting techniques.  As our killing methods advanced, the more wary animals survived to breed.  Later European man, in South Africa, had almost eliminated Africa's megafauna when he realized that everything he held dear was about to vanish and set aside large parks and brought back the major megafauna that had survived early man. Once more under the first people but with European killing technology, the animals are on the way out again.

As long as we don't destroy too many animals there are all sorts of animals just waiting in the wings to appear and fill all sorts of empty places in nature at a rapid rate.  I know that sounds pretty strange so let me explain.

Let's use the tail of a monkey as an example.  Our monkey has a prehensile tail which he uses as a fifth hand.  As he travels through the trees, he holds on to branches with his tail, freeing his hands (and feet) to pick fruit.  Any monkey that suffers a mutation that makes his tail less effective has a greater chance of falling and hence of not passing on his genes to the next generation.  This constant removal of monkeys with less effective tails highlights one of the characteristics of evolution.  Once an animal or plant is pretty well adapted to its environment, natural selection has far more to do with keeping animals (and plants) the same  than it has  to do with producing new species.

Now let's suppose that some of these monkeys start to move out on to the nearby plains to use a previous unutilized source of food.  They no longer need a prehensile tail.  Monkeys with less effective tails are no longer selected against and all sorts of tail mutations can be retained in the population.  Let's suppose that a tail is even a disadvantage.  At the very least, it takes resources to make a large specialized tail so perhaps that would tip the balance in favour of monkeys without tails*.  Here something interesting can happen.

*This assumes that the tail is not co-opted by evolution**  into some new function.  If so, natural selection will fit it closer and closer to whatever function it is now being used for. 

**Sorry for the anthropomorphism but you know what I mean.

Genetic sequences to produce some characteristic have actuator genes at the start of the sequence.  They turn the sequence on and off.  You can see this in your development.  You aren't born able to father (or mother) children.  The genes to do this are actuated at puberty. See this neat link.

If one of these actuator genes is mutated in the forest monkeys in such a way that the animal has no tail, that monkey is at a great disadvantage but in our hypothetical  monkey, by contrast, who lives on the savanna,  no tail is an advantage.  Having the actuator gene turned off imparts an advantage and leads to this characteristic being fixed in the plains living monkeys.

Even though the actuator gene is turned off, the gene sequence is still extant.    Without the pressure of a constant selection against animals with less effective tails that was occurring in the jungle, this dormant sequence can slowly degenerate.  Most mutations are harmful and the sequence for a tail will slowly be mutated and degraded.  It is a very slow process.  Occasionally an animal will be born in which the starter gene is turned on and this animal will have a tail.  The longer the time since the actuator was  turned off, the more degenerate the tail will be.  In fact, even though we humans are multi-millions of years away from the last of our ancestors that had a tail, very occasionally a human is born with a vestigial tail.  How does this all relate to a rapid radiation of new species, that I mentioned,  to fill empty ecological nitches.

Suppose now that man has hunted all the jungle monkeys with prehensile tails for their beautiful skins.  This nitch is empty and there are monkeys close by on the plains that occasionally have a "throw back" to a monkey with a tail.  If too much time has not gone by, and the tail is still effective, such a monkey finds that he is much more adept in the trees than his fellow monkeys and he no longer has competition from the much more tree-adapted jungle monkeys since man has wiped them out.  That nitch fills up again and natural selection once again selects for more and more effective tails*.

*  This process of starting up a disabled genetic code is sometimes called atavism activation and also works in the opposite sense.  For instance, in the ontogony (embryonic development) of a chicken (and presumably other birds) a "dinosaur" tail starts to develop.  Then another sequence actuates which re-absorbs the tail.  Evolution works in wierd and wonderful ways.  If you could turn off this tail absorbing sequence, a chicken would be hatched with a a tail.  To go into all the inns and outs of the way you could produce new species from the genetic material hidden in the present species would get very messy.  This is just a hint. Incidentally, the same sort of thing occurs in the "hand" of a bird with the fusion of the distal bones.  Turn this one off and a chicken will have an "arm" much like a dinosaur.  Also, teeth begin to develop and are absorbed before a chicken hatches.  Turn off these three genes and  Presto "dynochicken".

Of course this all depends on the fact that we didn't hunt all the plains monkeys to extinction as well.  The more populations that exist, the more possibilities there are for rapid radiation of species to fill empty nitches.  Otherwise, evolution has to start from scratch again.

This site gives some amusing  speculations about what might evolve

However, even if we were to eliminate everything except single celled organisms, evolution would once more populate the earth.  It would just take far longer and the results would likely be less recongnizable than if more familiar animals were still alive to radiate into the emptyness.

For that matter, we would be very unlikely to eliminate all humans.  We are like cockroaches.  Very hard to kill.  Our present civilization would become the stuff of legends with these fabulous beings (us) having supernatural characteristics.  Humans of the future would have all sorts of inventive explanations for what uses the artifacts they found were used for. I'd love to be a fly on the wall and hear how they explained, for instance, those little plastic bits that we use to close the bread bag.  If it didn't fall so close to home it would be rather fascinating to see us eliminate ourselves as a species.

Destroying the Earth
When I talk about destroying the earth, I am talking about the biosphere and taking it back to an environment with only single celled organisms extant.  There is a way and we are pushing the system in that direction.  However even our awesome ability to destroy would be hard pushed to cause this much destruction.  Let me relate a little story first.

In a previous life I worked for a research outfit and we did some work for the Tsawassen ferry.  The Ferry takes off from Tsawassen which is located on the BC coast near the American border.  The bottom shelves off very gradually so they had to construct a causeway of fill to get into deep enough water for the Ferries to dock.  They found that seaweed was collecting in the angle between the beach and the causeway on one side and this thick collection of organic material began to rot.  It was thick enough to be anaerobic and one of the break down products of anaerobic decay is Hydrogen Sulphide.  Besides being smelly, and in fairly low concentrations, lethal, it was turning the nearby houses black.  In those days, the white pigment in paint was white lead and when Hydrogen sulphide reacts with Lead oxide it makes lead sulphide which is black.  We sorted out the problem but that is another story.

It has been suggested that previous extinction events, the production of Hydrogen sulphide from the oceans was a contributing factor.  Let's look at the most widely known extinction; the one that wiped out the dinosaurs.  Apparently a large chunk of rock slammed into the Yukitan peninsula and disrupted a layer of gypsum.  Gypsum is Calcium Sulphate and the extreme heating that occured would have produced acids of sulphur.  The total effect was a shading of the world, perhaps for a few years, and a sharp decrease in photosynthesis.

With photosynthesis largely shut down, the only oxygen entering the oceans would have been by diffusion and many of the oceans probably became deficient in oxygen and even anaerobic.  All the life in any part of the ocean that was depleated of oxygen would have died, rotted and produced Hydrogen Sulphide.  The food chain would have been totally disrupted since it depends on the growth of phytoplankton.    Hydrogen sulphide is highly toxic and would have contributed to the woes of the animal life on the land and in the seas.

At present, we have destroyed many of the fisheries of the world and are turning the oceans into jelly fish cultures.  Places where polluted rivers flow into the sea have huge blooms of algae which die periodically and turn the water dead*.  We are acidifying and warming the ocean.  It is conceivable that we could start a chain reaction by killing enough of the ocean that it depleats the oxygen in other areas which generate hydrogen sulphide and kill even more etc.

* These areas are not actually dead.  They still grow anaerobic bacteria but to us oxygen breathers this is a close to death as it gets.

It would be so easy to reverse all this but we seem as stupid as a species as we are intelligent as individuals.  Sad.

Solar power and the Ratchet Effect

The Ratchet Effect is why solar power won't be worth while for you to invest in --- or at least not as worthwhile as it should be.  For anyone who has true net metering, that is to say a single meter turning backwards when they are generating excess power, forget about this article.  It's not about you*.  But for anyone who is double metered (or stuck with a single meter with a  double read out) monitoring the output from his solar array,  wind turbine or small hydro system, read on.

*Actually, there is a way the power company and the government can still shaft you if you are net metered but it is diabolical.  I hate to mention it in case I give them the idea but, I suppose, it is better out in the open so that we can be prepared.  I have described it at the end of this blog.

The Ratchet Effect is most easily understood, by using the example of a day in which you  generate just exactly as much power as you  use but applies equally to any day in which you generate and use electric power (that is to say, every day).  I have written about it before but I want to put a name to it so from now on we can talk in Short Hand.  We can talk about  the Ratchet Effect without having to go into the whole explanation again.  So let's look at our hypothetical day in which you generate just as much power as you use.

Say you use and generate 60kWh on this day.  That is not what is registered on your meters.  Fortunately, in my jurisdiction (New Zealand) we are allowed to use our home generated power and only top up if we are short or send power to the grid if we generate an excess.  This is not so in all jurisdictions.  In Germany, for instance, every kWh they generate goes through one meter and every kWh they use through the other.  Do the calculations on that little lot and see what a scam it is.  At any rate, let us say, with the ratchet effect, your meters each read 10kWh.  That is the sum of the instantaneous amounts you imported and exported throughout the day.  Remember, that this happens because your meters record any instant that you are importing or exporting and no meter turns backwards..... And you will hardly ever be using exactly what you are generating.

This occurs because of the following.  Firstly, even if it is sunny all day from daybreak to sunset,  the amount of power you generate throughout the day looks like a sin curve.  That is to say, it starts at nothing, rises to a maximum in the middle of the day and falls to nothing in the evening. Your power use does not follow this pattern.

Then, few days will be sunny all the time.  There will be clouds passing in front of the sun, greatly reducing your power generation.  It rises again as the cloud pass by.

Then there is your use.  In a usual use profile, you will have a small peak of use in the morning, a larger one in the evening and automatic devices such as your refrigerator go off and on during the day.   If you are at home, you may turn your computer on for an hour sometime in the day and then turn it off.  So why is all this important.

What it means is that at practically no time will your power use balance your power generation.  In our hypothetical day even though you generate, over the whole day, exactly what you use, at any given moment, one or other of your meters will be running.  Both only run one way and that is up.  Neither of them goes backwards.  In this hypothetical day, at the end of the day, let's say that both of them read 10kWh.

Now you would think on first thought that the power company will simply take note of these two readings and say that, overall,  you have neither generated or used power.  Wouldn't that be nice.  Not on your nelly.   Ever ask yourself why they bother with two meters* if this is what they intend to do.  Why go to the added expense.  All they would have to do is to install a little electronic device to disconnect you if the grid goes down so that you don't electrocute the lineman that comes to repair the broken wires.  Then they could leave the old analogue meter with the rotating disk where it is, at no expense to you.

*which in most jurisdictions, you will have to pay for and also pay for installation.

The various ways  that the government and the power company can set up  the system are numerous.  Just remember, though,  that once you have installed your system, the power company (and the government) has you by the short and curlies (in politeze 'can change the rules any time they want').  They may tempt you into installing your system with a promise simply to subtract one meter from the other for billing purposes, and the government may say the same for tax purposes.  They may even do as in Germany and promise you a greater rate for excess that you generate than for extra you use.  This will generally be for a specified period*.  Ever get suspicious when something seems too good to be true.  It usually is.  Let's look at one variation.  There are many and each jurisdiction will have their own scam.  Remember that one or other of your meters is ratcheting up at any given moment.

* 20 years from installation in Germany, for instance.

Suppose that the power company gives you less for power you buy than for power you sell. That is fair and right.  The power company has to earn a profit from their business*. Let's say in our example they charge you 20c per kWh and pay you  10c per kWh.  In our example you have used a make up of 10kwh and sent d 10kWh to the grid.  You pay $2 and get $1 for that day and despite having generated just exactly what you have used,  you still pay a dollar. If that is the daily average over the year, your yearly bill is $365**.  Remember, this is the excess sent and received due to the fact that both your meters ratchet.  They record the instantaneous export and import and meters only go upward.  No meter turns backward.  Of course the situation will be worse than this.  We still haven't talked about summer vs winter or about totally overcast days vs totally sunny days.

*Note that the way the power companies structure their costs is to charge you some fixed costs, correctly characterized as Line Charges, theoretically for the maintenance of the lines, and charges per kWh you use.

** Plus, of course your line charge which is a fixed charge for the privilege of being connected to the power company.

A second possibility is that they give you exactly the same price for the 10 in and 10 out.  Your bill is zero but hold on.  The government is something else again.  They will charge you tax at your marginal rate (say 33%) for the power you sell to the power company and GST at 15% (in New Zealand) for the power you buy from them.  If again power costs 20c per kWh, you will pay 66c and 30c = 96c to the tax office for the power you used and generated that day.

What is more likely is that you will pay the dollar to the power company and the 96c to the government despite having generated all the power you used that day.  In actual fact, in my jurisdiction, the typical price the power company pays is nearer to 5c

I'll leave you to work out other possibilities.  They depend on the system which is in place in your bally-whack and there are many  possible variations.

Just remember, with your twin meters ratcheting up - the Ratchet Effect - small renewable power becomes far less attractive.

The Net Metering Ploy
I mentioned at the start that the power company and the government can still "pull one" even if you are net metered.  It goes like this.  With the advent of small power generation and the installation of new meters, it is likely that "smart meters" will be deployed.  This is for, the most part, to the benefit of the consumer since the smart meter should be able to talk to your devices and turn them on and off to take advantage of less expensive power when there is excess generation.  However the smart meter will also talk to the power company.

There will no longer be any necessity for meter readers since the company can read your meters remotely whenever it wants to.  Suppose your power company sets up its computer to read your meters as often as possible.  It should be possible, for instance, with today's computer power to read them every minute if they so desire.  You see where we are going with this.  In one particular minute interval your single meter increases from X to X+x.  The x is how much net power you have used, above your home generation, in that interval.  This is accumulated with all other x's in your power import file.  In a different one minute interval, your  meter decreases from X to X-y.  The ]y[* is how much you have sent to the grid in that meter.  These are accumulated in your export file.

*The absolute value of 'y'

We are now, essentially in the same situation as we were with double metering and the company can charge you as they decide.  The government, will, of course charge you both types of tax.

Watch out.  Any scheme a government puts in place is rarely as attractive as it seems and the more attractive it seems, the more likely that it is a scam.  It may be a scam now or in the future when they change the rules.  A good first blow for the consumer is to have true net metering but even then you have to keep your guard up.

The ice recovery of 2013

Much has been made, especially amongst the climate change deniers, of the recovery of Arctic ice in 2013 when compared with 2012.  The ice extent (area covered) in the middle of September 2013 is approximately 60% greater than the ice extent of 2012.  A few comments are in order.

Firstly, this a recovery from a very low level.  This is 60% above the totally unexpected (at least by climate change deniers), exceedingly low ice extent of 2012.

The second point is that even though this was a big increase above this low level, if you look at the trend line (linear regression) in the following graph, you see that the ice extent of 2013 is only just above the trend line.  The September ice extent since 1978 has been decreasing at 13.7% every 10 years and the value for 2013 is very much in keeping with this trend.  Looked at another way, the ice extent for 2009 which you will see is just above the trend line was 5.63 million square km while for 2013 it was 5.35 million square km;  a slight decrease. There have also being other "recovery" years, notably from 1995 to 1996 without any lasting effect.  Looked at still another way, if this was really a recovery of the ice, you would expect the 2013 dot to be as far above the trend line as the 2012 dot was below it.

September 2013 compared to previous years

Figure 3. Monthly September ice extent for 1979 to 2013 shows a decline of 13.7% per decade.

Credit: National Snow and Ice Data Center 

Going out on a limb here, it would appear, looking by eye, that a downward curving, exponential line would fit the data points better than a linear regression (straight line).  In which case we can expect, in the coming years, some very low ice extents  in September, rivalling and exceeding the 2012 values.  In other words, ice melt is accelerating.  Even if the decrease in ice extent only continues as per the linear trend line, the Arctic will be ice free in a couple of decades.  If ice decrease is actually accelerating, we only have a few years to go.

Note that here we are talking about the ice extent in the middle of September when it is its lowest.  Following a zero ice extent on September, with small ups and downs, the ice free period will increase year by year.

If you want to see what ice volume has been doing click here. 

One further point.  In a previous blog, I described how Coriolis tends to concentrate surface water and ice into the centre of high pressure (sunny weather) systems while low pressure systems (cloudy weather)  spread things out that are floating on the surface.  2013 has had predominately low pressure systems and the ice extent could, to some extent be an artifice.  NSIDC measures ice coverage above 15% as complete ice coverage so spread out ice would appear as more ice even if it is not.  But let's say, for the sake of the argument that the 60% increase in ice extent is real.

The check on this should be the results from ESA (European Space Agency) satellite, Cryosat2.  By measuring free board (the height of the ice above the water), it can calculate the volume of ice in the Arctic.  As has often been mentioned, ice volume is a better measure of the true amount of ice floating on the Arctic ocean than ice extent.  It may be that I just can't find the data but if not, I would urge the ESA to release the information.  Then we could see if the ice really has increased 60% from Sept 2012 to Sept 2013.

ps.  Gaia has many mechanisms to try to keep the temperature constant on the earth (sorry about the anthropomorphism) We apparently are seeing one of them here.  With warmer Arctic water, air rises and gives rise to clouds which shade the Arctic ocean and reduce ice melt.  I wish Gaia luck in the attempt.  We are pushing her pretty hard.

This is one of the best graphs I have seen.  It shows that this year is only just a line width above the 2010 to the present average.  Not much of a recovery.  Sorry about the size. Click on the image to see a decent sized version.

 
You will notice that the space between successive decade averages gets wider and wider.  In other words, ice melt is not increasing linearly but is accelerating.

Just an amusing thought to finish with.  There will come a year when the ice extent is zero.  The year after that, there is likely to be a recovery.  Look at the graph.  It is a ever decreasing saw tooth pattern.  On the year after the zero ice extent, no matter what the level of the recovery, the climate change deniers will be able to claim an infinite increase in ice extent.