The Statistics of Climate Change - A Case Analysis of Dr James Hansens 2012 Paper

The Statistics of Climate Change - A Case Analysis of Dr James Hansen's 2012 Paper

Climate change is such a hotly debated topic that almost everyone has an opinion on it and even to not have an opinion ("I just don't know") is a valid opinion as many believe that we still do not have enough data to swing the decision in either side's favour.

The phenomenally controversial head of the Goddard Institute of Space Studies of NASA and noted Anthropogenic Global Warming proponent, Dr James Hansen has published a paper called Perception of Climate Change, in a scientific journal called Proceedings of the National Academy of Sciences, in which he gives statistical data for temperature changes over the last six decades in the Northern Hemisphere of the Earth. Using this data, Dr Hansen concludes that the Earth has been getting much warmer and that the evidence is incontrovertible. Further he also claims that extreme weather situations have become much more common than earlier. The Economist has carried a story on this study and this is where I first read about the study.

The data graph of the study given in The Economist

Description of the Graph :

• The data plotted pertains to temperature readings during the months from June to August for six decades starting from 1950s down to 2011 for the Northern Hemisphere.
• The data plotted is relative data not absolute data. This has been done to facilitate better comparisons.
• The reference curve (given in Dark Brown) comprises the average temperature values from 1951 to 1980; this builds a base with which to compare the temperature variations in each of the six decades. 1951-80 has been taken as a reference because this time period is long enough to build a normalized data range.
• 0 marked on the X axis (standard deviation) is the average temperature for the reference curve (1951-1980), which obviously has a sstandard deviation value of 0.
• The data for each decade is Normally Distributed and hence the peak frequency value for each decade coincides with the Mean(Average)/Median/Mode temperature of that decade. Further the 68-95-99.7 rule holds wherein 68% of the temperature values for any decade fall within 1 standard deviation on either side of the Mean temperature value, 95% temperature values fall within 2 standard deviations on either side of the Mean and 99.7% fall within 3 standard deviation.
• Dr Hansen describes an "Extreme Condition" as a temperature value which falls beyond 3 standard deviations from the Mean ie beyond 99.7% of the temperature range. This obviously has to be an absolute limit because uncomfortable or harmful weather is mostly an absolute figure in the short run. In the long run, life could perhaps adapt to the permanent changes but then a few decades can not be considered enough for adapting to these extreme conditions. These Extreme Conditions are perhaps the most important part of the data, from Dr Hansen's point of view.

Conclusions from the Graph:

• The data plotted clearly shows an increase in the average Summer temperature with each new decade. This can be observed from a right shift, along the X axis, of the Mean temperature value for Reach successive decade as shown by the peak of the Normal Curve for that decade. The Reference Curve's Mean temperature value moves from 0 to 1 for 2001-2011.
• The data also shows a much broader range and hence variation of temperatures for each successive decade. This can be seen from the increasingly flattening Normal Distribution. As one moves from one decade to the next, the frequency for the temperature starts to spread out over a wider range which shows up as a lower and flatter curve than the one for the previous decade. This means that since 1951 temperatures have been fluctuating as an ever increasingly pace. This large variation translates into lesser and lesser equitable climate, lesser reliable weather and could mean greater stress on crops and businesses and more discomfort for people, animals, plants and vegetation in general. The number of recordings for the Mean temperature drops from 0.4 readings in the Reference Curve to 0.3 in the 2001-2011 curve.
• The cases of Extreme Conditions in weather,as defined by Dr Hansen, were about 0.3% or less for the Reference Curve but for the 2001-2011 decade these were 6-8% or even more for the hot right side of the curve (though not so for the cold left side). This can be inferred from the right most part of the 2001-2011 Normal Curve, representing perhaps 1.5 standard deviations which  has crept in the zone of Extreme Heat. Hence there are 6-8% temperature values for the decade of 2001-11 which fall into the category of Extreme Heat. Hot weather extremities are clearly on the rise as well.

Positive Attributes of the Study:

• The GISS data is all encompassing. Data for the entire Earth has been collected. This is not a sample survey, this is a reading of the entire data universe (the entire Earth in this case). Climate is always a global phenomenon (as opposed to weather) and that is why climate change can only be talked about on a global scale. Rising temperatures in one or many parts of the globe will always be concomitant with other related phenomena in other parts of the globe. This universality of data is one of the two big advantages of this study. On the flip side however, only the data for the Summer months in the Northern Hemisphere has been actually plotted in the Normal Curves (see the Doubts section below for more details)

• Data plotted is actually recorded data, not future projected data. There are no modelling results used here, no assumptions to validate or disprove. This is all genuine and historic data, hence the readings, at least, are unassailable. This, absolute independence from projected data to my mind is the the other big advantage of this study.

• This data analysis has been accepted by a leading scientific journal called Proceedings of the National Academy of Sciences and this gives it some serious credibility, though, it is no guarantee of the water tightness of the analysis.

Doubts over the Study

Statistics have to earn our trust. We can't give it away for free to them. They have to be able to withstand our scrutiny. And this applies more so to statistics we want should be true, the ones which prove something we hold dear. Or else, suddenly, we might find ourselves betrayed by our own hasty acceptance of data we want to believe in.
Data Doubts

• Is a period of 60 years enough to provide data for climate change? What is the accepted time  span amongst the scientific community for talking about climate rather than weather, especially when discussing long series temperature changes? In fact, is there is any consensus at all about the time span? What results do we get when we analyse the data for the last 100 years (provided we have reliable global temperature data going back that far).

• Why only plot the data for the Northern Hemisphere and not for the Southern Hemisphere? Perhaps one explanation can be that this has been done in order to facilitate a true comparison. Summer in the Northern Hemisphere extends from June to August, whereas at this time the Southern Hemisphere usually experiences Winter. Hence in order to compare apples with apples, one needs to select the Summer months' data from one hemisphere ie compare June-August data for each year for the Northern Hemisphere and compare December-March data for each year for the Southern Hemisphere. The temperature data for the Summer months in the Southern Hemisphere should be plotted separately as a Normal Distribution for a truly global analysis. If there is indeed global warming taking place then the data for the Southern Summer months will further support this conclusion because, again, climate is a global phenomenon.

Correlation and Causation

Although, in this scientific paper Dr Hansen has not made any claims about the causes of this clear rise in global temperatures, he is a vociferous advocate of Anthropogenic Global Warming (read human induced global warming) and will place this data analysis in that context.

I think the single most important caveat for anyone looking at statistics, be they of weekly milk prices for one's household budget or climate change figures, is to not confuse correlation with causation. Sympathetic movement of two things does not imply a dependency relationship between those two things. Recently Krishnamurthy V Subramanian of the Indian School of Business has written a very lucid and meaningful article on the difference between correlation and causation. It can be accessed here.

I believe that climate change is being brought about human actions.I don't know this but I believe it. I am constantly trying to find ways to reduce my carbon footprint. However I do not wish to be slotted into either of the two opposing camps.

However instead of going into why I believe this I would like to dwell on some questions come to my mind based only on rationale. The answers to these questions will need more data and analysis but once answered they will perhaps help convert my belief into my knowledge and certainly aid policy makers and businesses to come to terms with the reality of our economic activities (again provided these questions are answered).

These questions directly address the correlation and causation problem for this study on climate change. Answering these could help convert any correlation between greenhouse emissions and climate change into a casual relationship and further even establish the direction of the relationship.

• How are we certain that human action is causing climate change? Evidence seems to suggest that for all of the previous climate changes in the 4.5 odd billion years long history of our planet, humans have not even been around to witness them, let alone influence them. 
• Other causes need to be eliminated (though I personally do not give much credence to most of them) such as increased Solar activity, fundamental geo-changes, inner core dynamics etcetera.
• Perhaps this time, that we are living in, is the inflection point of a very long run millions of years long climate cycle and hence this sudden acceleration might be a regular thing before such a cycle enter the next phase.
• Could it be that in the absence of greenhouse gas emissions temperatures would drop rapidly? Is human activity somehow forestalling the next Ice Age, is this delaying of the Ice Age somehow better (but at what cost)? Perhaps there are some human activities which are masking the effect of excess CO2 (such as smoke emission which cools as opposed to CO2 emission which warms)

The data above clearly points to increasing weather temperatures in the Northern Hemisphere since the 1950s. Further heat extremities are also rising, fast. But I do need to clear my reservations, as given above in the Data Doubts section, before I can whole heatedly embrace the analysis. Perhaps within the next few years even more conclusive and exhaustive statistical studies on climate change will be carried. I eagerly await that time.


To know more about:

The Economist's story on the study published by Dr Hansen

Climate change Pro Anthropogenic Global Warming
New Scientist
NASA on climate change
Earth Observatory's global temperature data going back 2500 years
And this page which gives human greenhouse gas emission data alongside

Anti-Anthropogenic Global Warming
Telegraph
Skeptical Science
Wikipedia


Normal Distribution in Statistics
Cliff Notes
Stat Trek


Meanwhile, here in Delhi.......it's getting hotter and drier and more erratic........please ignore, as this is anecdotal evidence and does not make for good statistics ;)

It's official folks, we're a 7 billion strong family now

Many population based maps are available at this forum.

 

World Map (country size based on population figure) 

India Map (based on population figures), physical map given in faint outline.

Rajasthan, Gujarat, J&K, Uttranchal and most of the North East have shrunk drastically, whereas the metros have swelled up to hundreds of time of their physical size. Uttar Pradesh too has assumed a monstrous size.

82 prints of Los Desastres de la Guerra by Goya on an aimless Monday evening

Ultimately it was the faces. Just one look at the faces and I knew Goya had touched me deeply. He had made me feel the pain. The physical and mental pain of war. And the sheer futility. A waste.

I knew nothing of Goya before seeing this exhibition. I had ofcourse seen his famous work, The Shootings of May 3rd 1808. But I knew nothing of him, his style, his world. I had read some bits on the Penensular War in War and Peace but that was it. Then one aimless Monday evening I chanced upon an exhibition on a series of war prints by Goya. Goya, a Spaniard, was asked by a Spainish general to witness, and preserve in art, the attrocities being commited by Napoleon's troops in the cities of Zaragoza and Madrid during the Penensular War of 1808-1814. Goya went to the battlfields and the seiges and diligently, often in grave danger or under the protective cover of darkness, sketched out the scenes of agony and human suffering being played out before him. The outcome: a series of 82 prints called Desastres de la Guerra (Disasters of War).
I think each of the 82 prints influenced me immensely. The time I spent amongst them wasn't enough at all. I could look at these engravings over and over again; sometimes looking at Goya's excellent shading technique and his use of dark and light to highlight and conceal, at other times his forceful framing and  composition, and at other times just be lost in those scenes, feeling them, living them. Overwhelming.

The prints themselves are actually etchings/engravings called Aquatints.It think this is a great medium and coupled with Goya's mastery of technique makes for the perfect represtation of such a dark subject. Very effective.

If I was absolutely forced to pick 5 from the 82 prints which influenced me the most, these would be the prints I would select:

I have found a new favourite artist and also images which will always stay in my mind.

Know More:

The exhibition at the Instituo Cervantes - Click here
Goya  and the Desastres de la Guerra
The entire series of Los Desastres de la Guerra, in the correct sepia tone
Penensular War: Spain Vs. Napoleon

MKG

Still smiling :)

One of my favourites

Google Search Globe: some observations

Google Search Globe is available here

Google Search Globe  provides daily statistics on which parts of the globe search in which language and in how much volume. I choose to see Search Globe as a great interactive 3D globe which gives insights into which languages are dominant in which parts of the world for online searches.  Quite fun moving the World around. Needs WebGL in your browser.

Some observations on Google Search Globe:

• India searches only in English on google.com apparently. 

• Amongst the Indian cities Delhi uses google.com the most, followed by Bombay, Bangalore, Madras, Pune, Hyderabad and then Calcutta.

• Mumbai, Bengaluru, Chennai, and Kolkotta do not exist

• Bangkok (??), Jakarta (???) and Istanbul (?????) search more than any Indian city

• Singapore searches in English and a bit in Chinese, Hong Kong in Chinese mostly.

• All of South America uses Spanish except Brazil which uses Portuguese. Though West Indies uses Spanish, English and Portuguese.

• Despite Spanish being the second most spoken language in the USA, all the google.com searches from the USA are in English.

• A lot of people somewhere on the USA-Canada border near Montana do not use English (but which language do they use? can't be French, too far from France and Quebec)

• Canada uses English though Quebec uses French (ugh!).

• Egypt is all about the Nile

• Most (net-connected google.com-using) Australians live on the East coast.

• Polynesia searches :)

• Atlantis still chooses to remain hidden from the rest of the world.

• One or more of these: population, internet access, preference for google.com are so low in Central Asia and Iran that the region appears almost uninhabited.

• Surprisingly UAE and Qatar perform a majority of their searches in English (expats perhaps), though predictably Saudi, Yemen, Kuwait and Egypt use Arabic.

• Sadly, Modern European Languages have completely killed of all Western European regional languages (Basque, Piedmontese, Langue d'Oc etc) in terms of net usage at least.

• Werewolves and vampires inhabit Transylvania (and Manhattan).

• North Korea, Tibet, Siberia, Sahara, Congo don't care much for the internet.

• Both Arctic and Antarctic Penguins happily agree to eschew all things net and Google.

• Highest search volumes originate from USA, Europe, and South America

• The filthy human race has spread to almost all parts of the planet Earth.

• I have much to travel.

More info on Google Search Globe here

I really like WebGL, it is a beautiful way to interact with 3D content through one's browser, without the need to install any softwares other than a decent browser. One can explore the human anatomy, the World' geography, play 3D games, interpret 3D data and what not. Some more wonderful WebGL applications by Google are available here

Map of Names of Recent Revolutions - Jasmine Revolution

I am forever in love with maps. While doing a little research about why the revolution in the Arab world is called the "Jasmine Revolution" I realized that in recent years many revolutions have often been given non-political, non-personal names. So I decided to make a map out of this knowledge of names of recent revolutions. 

Libya and Syria are now included in this map. As of today, the 9th of April 2011, the date of the revision of this map, Muammar Gaddafi and the revolutionaries are still fighting each other in Libya and no negotiations have been started. Last night I did listen to a senior ex-Gaddafi minister on Hard Talk who was confident that Gaddafi is not going to be able to hold out much longer and the revolution in Libya will be successful. The NATO-led coalition is still fighting against Gaddafi's mercenaries.

Meanwhile in Syria 20 protesters more were killed in Dera in their struggle to overthrow President Bashar Al Assad. No progress there either. Each promise for reform made by President Bashar Al Assad is followed by a fresh wave of violence against the protesters. It's almost as if a promise made is a clear hint towards fresh retribution. So Syria is still in a revolutionary limbo as of now. Though the situation could change.

The revolutions and their names shown in this map chronologically are:

1. Carnation Revolution, Portugal 1974

2. Velvet Revolution, Czechoslovakia and USSR 1989

3. Rose Revolution, Georgia 2003

4. Orange Revolution, Ukraine 2004

5. Tulip Revolution, Kyrgyzstan 2005

6. Jasmine Revolution, Arab World 2010-2011

The Jasmine Revolution is a term specifically for the Tunisian events and I don't think the protests and unrest taking place at various hot-spots in the Arab World have all been clubbed under the umbrella term Jasmine revolution as yet. However it was Mohamed Bouazizi's sacrifice which sparked the domino effect in Tunisia, Algeria, Yemen and Egypt. The tremors are being felt all over the region and in certain Asian regimes as well.

I hope that the Arab people find themselves in a much better position once their struggle is successful. I also hope that peace comes to these people soon.

Click on the map to view a larger image.

I may have missed some other names of revolutions and I would like to know about these if this is the case.

Feel free to use this map for any purpose you like, just link back here / give credit. Email me for bigger file size or other file formats (pdf,gif,png etcetera)

Mumbai Attacks - 26/11 - Nov 2008

A lot has been said about the Mumbai attacks. I agree with somethings and disagree with some other things. Here are some things I feel the need to say to those who wish to know:

1. Save the money which would be spent on the candle and / or flowers and / or text messages to each other asking to burn candles. Let's say Rs5 are saved per person.

2. Donate these saving to Army Wives Association http://awwa-india.org/ or other such organisations. Assure the armed forces that we as a nation will continue on our own to support their families withouth passing the buck onto the government or to the army. The families of those who sacrifice their lives for the nation should be the priority of the nation. When they did not pass on the buck onto the government after being called to take charge how can we pass on the buck now?

Simple maths:

If each person above the poverty line living in just Delhi, Bombay, Calcutta and Madras was to donate Rs5 then the corpus would excees millions of Rupees.

Donate to anybody you want to or help otherwise (PM's fund, local gurudrawara, orphanage, school take your pic); all such actions help. But remember do not make them one-off-I've-done-my-bit actions. Small but continuous steps are better.

It does not matter how and where we help but we must. Our armed forces have our respect and rightly so. Even if they do not give up their lives just their presence is important. I can enjoy my life, go to the movies, do what I want, eat, drink, sleep, shop do whatever because there is somebody donning a uniform in my stead. He or she is there on my behalf, not on the government's behalf. Armed forces people risk their own lives for their comrades around them and for us, not for the government, not for the notion of India but for the people who are with them in conflicts (their teams, their group, their subordinates and colleagues) and for the people back home.

3. Ignore the glamour-affected-latest-hero-worship-fish-market-hollier-than-thou media houses which want to tell us how we should show solidarity with the armed forces of India and which news to focus on. Media houses (TV Channels esp) have a huge amounts of costs to recover; they are in an industry where the competition is extremely stiff.They have to make every second of air time count. Working the way they work is the only business model they know of and the only one that helps them to make money. They have to show returns on investments. It is foolish for the citizens of India to expect news TV channels to improve the quality of news reporting and analysis. Let the media be. We all get angry at them but they are to be pitied. They have no credibility and nor do they enjoy the respect of most of us. And of course this applies not just to the news channels but to the highly visible faces of these news channels, the so called news heads and to the content editors as well.

4. Do not forgive the politicians and the bureaucrats. Do whatever it takes to shake the fetid political foliage of our nation. Our politicians play with our lives our parents' lives our children's lives, destroy our youth, get the most courageous from amongst us killed for no reason (often facing terrorists without adequate equipment), dilly dally with reforms, cause the deaths of lakhs of Indian every year due to avarice, negligence and plain apathy and then the corruption...

One way is to invoke Sec 49-O of the Conduct of Election Rules Act 1961. Possibly the only weapon we the citizens have againt the politicians. It is our constitutional right as well as our duty.

Sec 49-O, under the Indian Constitution, essentially empowers each citizen of India to vote for "nobody". A voter can choose not to vote for anybody.

As of now this power can not be used by voters as the electronic voting machines do not have a nobody option but the Hon. Supreme Court of India is reviewing cases to get this option included. The Election Commission of India has also made similar recommendations. Although the Returning Officer at each booth can be informed of a "I vote for nobody" decision this would constitute a violation of the law which states that the decision of a voter can not be disclosed to anybody else.

With some changes this can become a possibility and in that case if the number of people in a constituency who exercise this option were to exceed the victory margin of the winner from that constituency then the election results would stand canceled. Re-election would have to be called for and none of the contenders from the initial election would be allowed to contest again.

Text of Sec 49-O

"49-O. Elector deciding not to vote.-If an elector, after his

electoral roll number has been duly entered in the register of voters

in Form-17A and has put his signature or thumb impression thereon as

required under sub-rule (1) of rule 49L, decided not to record his

vote, a remark to this effect shall be made against the said entry in

Form 17A by the presiding officer and the signature or thumb

impression of the elector shall be obtained against such remark."

Source - Law Ministry Website

http://lawmin.nic.in/ld/subord/cer1.htm

To know more:

http://en.wikipedia.org/wiki/49-O

There are other ways also, Checking the affidavits filed by the contenders in your area for criminal cases, and assets declaration among other things , using RTI Act for example.

5. Be good to each other as much as we can be. You love me I love you, to hell with the government, cause it just loves its own self (and even that can be disputed). The government is not the cure for all evil in our country, I have come across many in the government who are hard and honest workers and administrators. It becomes unjust to blame the entire government for everything.

All of us are busy, all of have problems and we can go on doing whatever we do, we can live our lives happily, we just need to make small efforts and do good.

There is some good news. I am happy to know that the Centre has decided to immediately setup new NSG bases in all the metros of India to reduce the reaction time in Mumbai-like situations (as of now the NSG is based out of Manesar near Delhi and it took them more than 3 hours to get to Mumbai).

Further,the states are also being advised to establish their own state-level NSG units which will be the first ones to reach the location of the crisis and act in concert with the Centre-Level NSG units (based out to Delhi and soon out of the other metros as well). The state-level NSG units will be of the same calibre as the Centre-level NSG units. Karnataka has already requested the Centre to help it establish and train a Karnataka NSG. I hope this plan works.

Just remember that more than 4/5th (40 odd) of the Mumbai Attack terrorists have escaped. They are now inside India and waiting for the right time. Better for all of us to be prepared and do our small bits.

Related post

http://azhdaha.blogspot.com/2008/12/symbolic-gesticulation-belongs-to-age.html

http://indianmilitarybenefits.blogspot.com/2008/12/rule-49-o-right-to-negative-vote-not.html

http://indianmilitarybenefits.blogspot.com/2008/11/heartfelt-condolences-irrespective-of.html