Saturday, February 6, 2010

Global Warming – Can it be Measured!

The entire gamut of GW is based on a simple fact or rather a hypothesis as many believe; that it is really happening. It’s worth pondering though, is our planet really warming up? If it is then is it due to natural causes or manmade ones? If it is due to natural causes, should we worry and what can we do to control it? On the other hand if it is manmade, should we worry and what can we do about it? And what if it is not warming up at all, rather cooling off, should we worry then or should something be done about it? What if the planet’s temperature is steady and is not appreciably changing either way? Is this a cause to fret about and should we leave it at that or do something about it.

Central theme running through all the arguments and debates as laid down above is the word ‘temperature’. To decide whether we as a planet are heating up or cooling down or no appreciable change in temperature, we first got to have a reliable temperature data over a reliable epoch to come to any kind of conclusion. That brings us to the most debatable and controversial aspect of GW. How do we measure the Earth’s temperature, where all do we measure, at what times, over how many years, to what do we compare it with to determine either a rise or a fall in the temperature. Can Earth’s temperature really be measured; is another highly debatable topic in today’s world. What if we have measured it all wrong so far, skeptics ask, what if our reference years have been arbitrary, what if our measuring instrumentations and interpolations and statistical probability analysis curves have been wrongly mapped or interpreted? These are serious questions that have mega chain reaction potentials since today GW is a trillion dollar industry. Entire nations and human populations are being urged to change their lifestyle, eating habits, etc based on these data and the premise that Earth indeed is heating up more than it should by natural process and it is us, mankind who is the sole cause of it hence we need to change the way we have been living and exploiting our natural resources. Let me try to solve this enigma in as non-scientific manner as possible within my experience.

When we talk about any trustworthy ‘scientific’ observation based data collection, measurements and outcome methodology we first got to understand what is ‘scientific’! This is easier said than done. Simply put scientific methodology means that is unambiguous, repetitive, which can be proved by different people at different places and times using same set of variables, etc. When we begin to even think as to how we can measure Earth’s temperature the magnitude of the problem becomes obvious. Earth’s volume and mass is made up of three distinct elements: earth, air, water. Each of these elements have numerous variables and forms. Their volumes are enormous and each of them show temperature related alternations in different ways, sensitivity and locations. There is absolutely no uniformity in these three elements from a climatologist’s point of view. The ways they absorb, reflect, retain, distribute and dissipate heat is also different. Hence for example, a rise in temperature in water may not be comparable to the same amount of rise in temperature in air or earth.

The water bodies, depicted by lakes, rivers, ponds, groundwater, swamps, seas, oceans are so widely varying and affected by such diversity of phenomenon that there is no way we can measure temperatures at all the places that we should to arrive at a scientific data that can be taken with absolute authority. Ocean depths make it all the more confounding. Marine lives, underwater seismic activities, ocean currents, surface air temperatures, etc muddle the process further. There are thousands of ships, millions of buoys and ocean bed sensors collecting hydrological data round the year, even then we can only draw probability curves and can’t really pin point at one temperature with accuracy to the level of infallible science. Which temperature from which point in terms of depth or location should be taken as the water temperature of Earth is a question that has no answer till today. We don’t have enough data to even draw a reliable average. 98% of world’s total water in volume is saline and is locked within the seas and oceans. Therefore most of our efforts at measuring water temperatures are focused solely towards this mass of water.

For land temperatures we are concerned with surface temperatures where the land-bound surface (for the sake of land temperature) is generally considered up to a 100 m from land surface. Anything beyond and above would form a part of the air temperature readings. It has been observed that the reflected radiated heat from the land surface (which is around 28% of Earth’s total surface area) loses its heat due to its distance rapidly beyond 100 m from ground. Land features differ vastly from place to place. Population density, deforestation, high altitude mountains with glaciers and ice caps, highly industrialized areas, heavy duty energy generating units, etc have their own periphery of influences and the coastal land areas are in turn affected by the ocean and sea currents. Hundreds of thousands of land based meteorological stations monitor land temperatures round the clock around the world; even then as we will see subsequently, the data may not pass strict scientific scrutiny.

As for the atmospheric or air temperature measurements we face a herculean task. Let’s first understand our atmosphere and how it heats up as taught in class V geography lessons. Total mass of Earth’s atmosphere is around 5000000000000000000 kg of which nearly two thirds is found within first 10 km from the surface. Atmosphere comprises of five layers, from bottom to top: Troposphere extends to around an average of 12 km with wide variations between the surface over Equator and the Poles, Stratosphere goes up till around 50 km, followed by a buffer zone called Stratopause that goes till another 5 km in average, it is taken over by Mesosphere that goes up till around 85 km, surmounted by Thermosphere going up to around 360 – 700 km from Earth’s surface beyond which lies the Exosphere which is more or less a vast empty space comprising mostly of helium and hydrogen. It goes up till around 10,000 km till it merges with the outer space. There are three ways that heat gets circulated within the air; conduction, convection and radiation. The seemingly invisible atmosphere has different elements in differing densities within different layers that are affected by pressure, density, optical properties, Earth’s spin, etc. They form a complex system for trapping and radiating heat. Most of our man made heat causes the atmosphere to trap heat more effectively hence in terms of our GW studies; an understanding of atmospheric temperature is perhaps paramount. The only way we can measure atmospheric temperatures is by weather balloons, satellite data, and manned and unmanned probes.

Today the world of science, economics, politics, general public, thinkers, industrialists, venture capitalists, bankers and the Nobel Foundation (for reason recently unearthed) is divided into two views. I would say fifty-fifty, with one half supporting the hypothesis that our planet is indeed warming up more than it should naturally do, due to manmade causes while the other half opposes this view and trashes it completely. There’s a miniscule of people too who believe that the Earth is not warming up at all, irrespective of any natural or manmade effects. It is actually cooling down. They uphold that we are seeing the beginning and onset of the next little ice age, the last of which had happened between 1550 – 1650. Before we proceed further let me make my stand absolutely clear; I belong to the first half and I firmly believe that our planet is warming up at a rate that is more than what it should do naturally. We as inhabitants of this planet are affecting its climate and making it warmer by our direct and implied actions.

The difficulties of measuring Earth’s temperature and checking it against a reliable referral point, as shown above, in order to arrive at the conclusion that it is indeed warming up is an impossible task to achieve in its totality as science would ideally dictate. Weather prediction, as it is widely known, uses the most complex and expensive computers in the world, for data collection, recording and predictions; even then they are way off the mark in almost 40% of the predictions. Till date I am yet to depend solely on any weather predictions for my expeditions. We all know that sun shines on a predicted ‘rainy’ day and you wish you had carried your umbrella on a predicted ‘sunny’ day. Trillions of dollars are spent worldwide to make our weather predictions along with storms, natural calamity predictions more and more accurate, yet Katrina strikes, floods happen, tsunamis devastate with regularity defying our so called scientific achievements in this field. Despite this we don’t trash our meteorological stations or weather mapping agencies. Similar is the case with measuring the world’s temperature and predicting what is really going on.

Science and scientific investigators, both theorists and field workers along with lab workers, are among the most dedicated and tenacious species of human beings. If it weren’t so, then we would still be living in the dark ages. They don’t give up on the face of ‘impossibilities’ nor do they rest on their laurels. One more point I want to draw attention to is an inherent fallacy that at times crop up in any scientific experiments. If an experiment is conducted with a pre-determined outcome then it affects the experiment in producing the outcome. For example when particle physicists tried to prove that light is a particle, it behaved like one and when they tried to prove it is a wave, it behaved like wave. This is important to remember since there have been models drawn to prove that earth is warming up and hence it proved so, whereas the opposing group experimented with the presumption that earth is cooling down so they got their cold prediction models. Therefore it is important to remember that while experimenting, data collection and analysis we must keep an open mind wiling and ready to accept the outcome, whatever it may be. In all such open minded experiments it was proved that earth was warming up at a rate that defies the natural process of temperature variations or oscillations as it is called.

It is surprising that though we have been measuring temperatures on a global scale since the mid nineteenth century the concept of global warming or the thought that Earth might actually be heating up due human actions came into existence only as recent as 1987, which is precisely the reason why Intergovernmental Panel on Climate Change (IPCC) was formed by the year 1989 under the aegis of World Meteorological Org (WMO) and United Nations Environment Program (UNEP). It was realized that the warming would be affecting the world climate in a major way since almost everything that happens in our atmosphere and oceans in terms of climate happens due to the exchange of heat and varying temperatures. Based on the 1990 report of IPCC it was realized that issues involving climate change were of such magnitude that nations and governments would have to raise the climate platform to the level of political governance. National policies would have to be formulated and actions need to be taken at the UN Council level. What kind of measurements made this happen, since till then no one even thought seriously about any such phenomenon called GW.

One scientist by the name of Dr James Hansen of the Goddard Institute of Space Studies, New York in 1988 claimed to have found a reliable method of calculating global surface temperature. To explain in details his methodology is way beyond the scope of this post. Simply Google the name and you will find tons of literature on it. In very brief the method involved dividing the world’s surface into 5 deg X 5 deg of longitude and latitude and collecting data from each of these boxes. By mapping the world this way and by comparing the data over 100 years we see that most of the earth’s surface temperatures (including sea water temperature) at an average do show some rising trend. Though this is highly debatable since there are several flaws in this data. There are assumptions, limitations, etc that were necessary for coming up with any conclusion at all. Many anti-GW authorities have found flaw with this method and have trashed it effectively (please remember my earlier statement that if you analyze on presumptions, you are affecting the outcome). We had other methodologies as well to fall back upon. These are called proxy measurements by measuring the tree rings, sedimentations, etc and then from weather balloons (radiosondes) and Satellites. All of these methods too show some marginal rise in earth’s temperature. It is pertinent to mention that the temperature data on which we work out GW models are mostly gathered with some amount of accuracy from the developed nations, primarily USA, Canada, Australia, West & North Europe, Russia, etc whereas vast tracts of Africa, Asia are left out of the loop. Though for the last decade or so China and India have taken huge steps in this direction, temperature measurement based predictions typically need at least 25 – 30 years of data to work upon. Proxy measurements have typically studied the effects from nearly 1000 years before whereas the other methods are for a much shorter time. Compared to Earth’s accepted age of 4.6 billion years, this period is ridiculously small. Geologists often include and accept error to the tunes of few thousand years. So what is prompting us to take the notion of GW so seriously and by some so offensively?

The answer to the above is simple and primeval as heat itself. Simply by calling upon our common sense and by visual and simple observations across the globe we can safely presume (even when our scientific data fails to prove conclusively) that the world is indeed heating up at a rate more than its natural process and it is being caused by us. We go back to our greenhouse gas emissions and their characteristics. You can read about these gases in details in my previous posts. Due to population explosion leading to industrialization, urbanization, deforestation, energy production and fossil fuel exploitation we are today generating enormous quantities of greenhouse gases into the atmosphere, toxins into the sea and eroding our topsoil beyond repair. It is impossible that none of these actions are not affecting our planet, even when we can’t measure them adequately to draw irrefutable conclusions! Never before has Earth seen such ravage of this magnitude. We don’t even know accurately how much devastation is happening worldwide. Loss of species, bio-diversity, fresh water, arable lands, and clean air are all compounding this massacre that we are causing exponentially. We are choking ourselves and starving our people. Remember most of the world’s population is facing annihilation due to the action of few. We may keep tossing figures and numbers at each other, like the present debate raging all over the world, if Himalayan glaciers are indeed going to vanish by 2035 as mentioned by IPCC in its report and should Dr Pachauri resign and return the Nobel Prize, and doubtless that they will not disappear even in the next fifty years, they are reducing and losing mass at an alarming proportion. I do hope that these people, rather than getting stuck with a number and hounding IPCC to death, would look at the larger picture.

I have personally explored the world’s longest and most voluminous glaciers (expect Baltoro in Pakistan) in both non Polar and Polar Regions and can say with confidence that there is none that is today gaining in mass. Though they are supposed to lose mass they are doing so at a much accelerated rate. The Polar Regions too are shedding their bulk and breaking up at an alarming rate. Loss of Polar Ice caps will perhaps not cause instant flooding across the world or submerge Maldives or Netherlands but they will certainly inundate low lying coastal areas. They will certainly give rise to unprecedented natural calamities like El Nino or Katrina. These are the regions that are highly susceptible to any change in temperature since they are acutely sensitive to rising temperatures. Polar Icecaps and the mountain glaciers across the world are shrinking for sure and at a faster rate than they naturally should. This is not mumbo jumbo or my wild theories. When we see the change in our living pattern and exploitation of earth’s natural resources vis-à-vis the occurrences at the Polar Regions and the glaciers around the world, the direct relation between the two cannot be overlooked.

To summarize this post, we have seen how a foolproof scientific methodology or data is not available to us today to conclusively prove that whether the Earth is indeed warming up and if it is then is it attributable to natural or manmade causes. Even then by studying the effects and common sense we can safely conclude such is the case. In my next post I will discuss the observable effects of GW in our Polar and non-Polar Regions.

2 comments:

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  2. Extremely informative, Satya and as always you do have a point to make!

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