http://io9.com/5922411/predicting-re...with-easy-mathRandom events, like high or low temperatures, rainfall (or lack of it) per year, and overall crop production, are unpredictable. And yet, within a certain space of time, there are ways of predicting how often record-breaking weather will come around. Call it the easy math of climate change.
There are ways to tell when some records are going to be broken. Whenever engineers design a better swimsuit, the world is ready for new records at the Olympics. But some events, like weather, are dependent on so many variables that no one could predict exactly when a record year will strike. Statisticians can, however, predict how often a record year will strike over a particular span of time, and it takes some relatively simple calculation.
For the sake of simplicity, we'll estimate that whatever is being measured is a yearly occurrence – say, average temperature. Record keeping begins with the first year. The first year records are kept is always a ‘record-breaking' year. If someone were to look at the records being kept for anything, anywhere, at any time, yearly records kept for one year will have one ‘record-breaking year.'
Along comes year two. Either the second year is even more extraordinary than the first, and is another record-breaking year or it is less. If there are two possibilities, there is a ½ chance of another record year. So looking at a huge number of two-year records, people will find an average of one and a half record-breaking years per record. Half of the year two records will have exceeded the year one records, and half will not.
Year three can either be higher than both years before, lower than both years, or sandwiched between the years. Three possibilities yield a one-third chance of being a record-breaking year. So the number of total number of record breaking years for a three year stretch of time will be one (the first year), plus one-half (the second year), plus one-third (the third year). Look at a huge number of three-year records and you will find 1.83 record-breaking years per record.
Eagle-eyed readers will have spotted a pattern.
For three years, the way to calculate the number of ‘record breaking years) is this: 1 + ½ + 1/3.
For four, it would be this: 1 + ½ + 1/3 + ¼.
And so it goes. So for N years, the way to calculate the number of record-breaking years is:
1 + ½ + 1/3 + ¼ . . . . + 1/N
Some things to notice, as the number of years recorded increases, the number of ‘record breaking years' does not keep pace. This makes sense given what we know of records. It's relatively easy to beat the world's record if it's only been kept for three years. There will be roughly two record-breaking years in there, and one of them very well might be you. A record that's been kept for thirty years will have roughly four record-breaking years, even though it's six times longer. A record that's been kept for a hundred years should only have about five record-breaking years. Five hundred years should only yield seven record-breaking years.
All these calculations are dependent on each year being completely random. If it isn't, there is some outside force acting on it. This is one of the basic calculations that worry climate scientists. If a record of Canadian weather shows six record-high heat waves in the last forty years, when there should only be around four, while another record for Antarctica shows five when there should be around three, and all other records, everywhere, show an above-average number of record-breaking heat waves, then something is driving the temperature up. In a truly random world, there wouldn't be so many records being broken.
Sun activity has been going down in the last decade and average temperatures still went up.But our weather is dependant on a outside effect foremost sun activity...
Sunspot activity might have been decreasing as per 11year cycle, but they're cooler patches on the surface, so naively that means more energy given out to us when there's less spots. Of course it's probably far more complex than that.
Also, atmospheric temp is a function of energy, but in balance with pressure & humidity, etc. I would have thought there's all sorts of dynamics with more powerful winds or heavier rains due to more energy in the system, without the actual temperatures changing. Like basic physics demos with water phase changes (ice/water at 0, water/steam at 100, then vary the pressure to make it boil at less or more). That and the different layers, which vary in height according to many such things, and you could be measuring a different temperature just because the same volume of air at the same temperature it always was has moved to where you're taking reading, without more hot air necessarily forming.
In Venus's case the lack of atmospheric gas replenishment thanks to a one-piece crust, and the lack of a strong enough magnetic shield to stop hydrogen being blasted from the atmosphere causing the loss of the ability to form water leads to a high pressure atmosphere that is as much a cause of the heat as greenhouse gases.
And now the fear that changes in salination will cause hte Atlantic Conveyor to shut down leading to dramatic cooing in Northern Europe is back.
If you study the climate data you'll see that we are actually statistically rather late for an ice age. Obviously it is hard to pick long term tends out of the background noise of natural fluctuations in climate but it seems that a cooling phase halted and then reversed roughly at the same time humans discovered agriculture. So man-made warming my be far older then our use of fossil fuels.
It is interesting to think that parts of the world - the fertile crescent, the North African Coast, the yellow soil region of China - were once the bread baskets of ancient empires and yet today are deserts and wastelands. The herding of Goats has massively expanded the Sahara. Most of the worlds forests are now gone, takng within them their cooling effects via transperation. CO2 is only part of what we have done to change the climate, possible the final straw, possibly not.
Last edited by Maximillian; July 19 2012 at 12:18:02 PM.
If you store more energy in the system the energy should be sooner or later averagely distributed over the entire system so the differentials should be relatively the same. But please point me to an article if you have one handy that explains it in more detail since I never did more then just basic meteorology / thermodynamics.
The world isn't just a petri dish where everything gets equalized eventually. As I said already, temperature increase is not uniform. Hint: blue is a temperature drop. I.e. an area where melting snow/glaciers suddenly reveal dark rock or soil will be heated up significantly more than other areas.
And since the temperature gets increased by different amounts this changes the atmospheric circulation patterns. This can lead i.e. for a stream of cold arctic air to follow different routes than usual. The region where it flows through now also gets warmed up by the general global warming effect, but the different circulation pattern counteracts this. Another example would be an area getting more rain than before - the increase in cloud cover and the energy intake of water evaporation would also have a cooling effect which can reduce or counter the basic temperature increase.
Actually *look* at your image.chart
From 1920 to 1960 it looks a bit like a correlation except there is a tiny problem: The temperature increase happened *before* the sun spot activity. Unless sun activity travels through time and effects our climate 10 years before it actually happens there is no real correlation since 1900.
Of course the sun effects our climate, but it is not the cause of the increase of the average temperature.
Last edited by Aramendel; July 19 2012 at 01:55:02 PM.
Well the temperature did drop in the very last portion of the graph, very very very little but it did drop :P
In before cosmic rays.
And no, our atmosphere is a little more complex than that. Shifts in jet streams could potentially cause some places to be much colder than usual (like north america/Europe over the last 2 winters, due to the polar weather systems "expanding" southwards) for instance. Combine that with things like how the largest bodies of land will by far experience the greatest increases of temperature and this notion that the laws of entropy will even out increases in temperature comes increasingly thin.
On a slightly more positive note, Germany has been doing great things with solar power.... ehh.. despite the apparent bankruptcy of a bunch of their solar companies, anyway. They reached a peak of 40% of their total energy consumption coming from solar in the middle of the day one day in May. Yes, yes, it was only brief and long term it's nowhere near being sustained at 40% but still very cool.
Also a new free solar setup thingy just appeared where I live so I may get the folks to stick some panels on their roof. The cost of photovoltaic cells is going way down.
Originally Posted by Loire
Wow, what a gross and erroneous oversimplification of probability mechanics....Along comes year two. Either the second year is even more extraordinary than the first, and is another record-breaking year or it is less. If there are two possibilities, there is a ½ chance of another record year.
Hey guys, I'm thinking of driving my car across the province and visit some relatives. There are two possibilities; that I reach my destination unharmed, or I will be injured in a car accident on the way. Therefore since there is a 1/2 chance that I will be injured in a car crash, I conclude that my planned trip is too risky.
First off, on your first trip, according to the model, your chance of an accident is 1, or 100%. This should tip you off that you aren't using it correctly or that it's really completely off the wall broken and more than an oversimplification. That's because you do have a 100% chance of setting any record you want to measure on your trip. For example, a speed record. Grats, you've set your first speed record. Now drive again randomly. You have a 50% chance of breaking that record. Etc.
Seriously, I don't think the guy completely made up that model out of nowhere. Maybe he did. But it's not quite that awful.
Originally Posted by Loire
oh no, the weathers too nice, oh no
(i didnt read past the first post)
Not getting into numbers argument here, but my dad remembers skiing on local runs during Thanksgiving weekend when he was my age. He did this for many years. And it was natural snow, not man-made.
In my 28 years of life, in the same area, that has happened maybe two or three times. This past season, we didn't get any appreciable snow until January.
roh roh, fight da mirror powah
Federation Horticultural Corps
It was until India and China started going gangbusters on modernizing.
roh roh, fight da mirror powah
Federation Horticultural Corps