In the November 25 issue of Current Science, researchers from the Indian Space Research Organization release a map and some important estimates of the extent of land degradation and desertification affecting mainly dry, semi-arid and dry- sub humid areas of India.

Land Degradation: Land Use and Processes

Source: Desertification/land degradation status mapping of India

About 69% of the total land area of the country – about 228 million hectares – falls in one of these three climatic categories. The numbers from this mapping project is cause for concern. They indicate that land degradation has affected just under half the extent – 105 million hectares of these dryland regions, roughly 32% of the land area of India.

The main processes of degradation are water erosion, wind erosion and vegetal degradation through deforestation and overgrazing. The paper gives the extents affected by various degradation processes grouped state-wise.

I wish they had included estimates of degradation by land use. For example how much of agricultural land in each state is being degraded, how much forest and so on. These have been no doubt calculated. They show up as classes on the map, but the paper does not present the results by type of land use affected.

If predictions about changing rainfall patterns over India because of climate change turn out to be accurate they will accentuate many of these degradation processes. Rainfall is predicted to fall in shorter more intense bursts over many regions of India. This would mean more powerful surface runoff and greater soil erosion.

Regions of country which are hot and arid like Gujarat and Rajasthan are likely to get hotter and drier. That would mean more stress on vegetation and great wind erosion.

I come back to the National Action Plan For Climate Change (15 MB) There are 8 missions or strategies to deal with climate change. None of these directly includes the problem of land degradation and desertification in dryland regions. However the National Water Mission, National Mission for a Green India and the National Mission for Sustainable Agriculture seem to have the right overlapping goals that could be focused to address this problem.

I mentioned earlier about the estimates of land degradation according to land use. These numbers matter a lot. Farmers occupying dryland regions are usually poor farmers cultivating marginal lands. If you look at the above map, you will see large regions classified as Agriculture Unirrigated being affected by various processes of land degradation. These are farmlands that are out of the reach of irrigation canals and other State largesse. Millions of farmers cultivate small land holdings, depending only on monsoons and groundwater. Warming and changing rainfall patterns will have a larger impact on these marginal farmers. Their livelihoods and the food security for large number of people in these drylands is at risk from continuing damage to the land.

The National Action Plan For Climate Change needs to single them out for special help.

The more familiar method of carbon dioxide sequestration involves capturing and pumping the gas into underground reservoirs where geological traps that have sealed natural gas for millions of years will serve to lock captured CO2 for eons as well.

Nature has published a paper by Jürg M. Matter and Peter B. Kelemen that proposes another method of CO2 sequestration, locking CO2 as carbonate minerals by reaction with a host rock.

Anthropogenic greenhouse-gas emissions continue to increase rapidly despite efforts aimed at curbing the release of such gases. One potentially long-term solution for offsetting these emissions is the capture and storage of carbon dioxide. In principle, fluid or gaseous carbon dioxide can be injected into the Earth’s crust and locked up as carbonate minerals through chemical reactions with calcium and magnesium ions supplied by silicate minerals. This process can lead to near-permanent and secure sequestration, but its feasibility depends on the ease and vigour of the reactions. Laboratory studies as well as natural analogues indicate that the rate of carbonate mineral formation is much higher in host rocks that are rich in magnesium- and calcium-bearing minerals. Such rocks include, for example, basalts and magnesium-rich mantle rocks that have been emplaced on the continents. Carbonate mineral precipitation could quickly clog up existing voids, presenting a challenge to this approach. However, field and laboratory observations suggest that the stress induced by rapid precipitation may lead to fracturing and subsequent increase in pore space. Future work should rigorously test the feasibility of this approach by addressing reaction kinetics, the evolution of permeability and field-scale injection methods.

The advantage here is that the gas is converted into a solid phase and so exists in a more stable form. The principle may be sound but I’m going to think out aloud on bridging the very long distance between scientific possibility and its practical realization in the field for a country like India.

First come the political and economic issues with a scheme of this nature. Those hurdles are immense. India’s stated position is of no mandatory limits on emissions, so there is no political urgency in examining CO2 sequestration projects like this one. And this method is going to be expensive as well. Transporting CO2 from emission points to suitable storage sites and then drilling and pumping gas in hard rock ain’t going to come cheap. It might work if the price of emitting CO2 is very high. But under the current scenario in India with no limits or penalties on emissions there will be no economic incentives for polluters to even explore a scheme like this.

Besides, there are other urgent practical matters that need to be carefully thought out before rock masses can be given out for CO2 storage.

There is no problem in India finding a suitable host rock. In Maharashtra and adjoining states of Madhya Pradesh, Andhra Pradesh there is half a million square km of Deccan Basalts, a rock rich in magnesium and calcium that will provide plenty of reaction surface and storage volume. This potential reservoir is up to 2 km thick in the central portions and along the western ghats. Other areas of the country too have mafic igneous rocks of the right composition that may extend to even deeper crustal levels.

However… where do you drill and store and to what depth before the project becomes too expensive?…

A crustal thickness of up to 1 km underlying cultivated areas must be kept untouched only for groundwater storage. That may seem excessive since groundwater is extracted mostly from the upper few tens to a hundred feet or so. But the Deccan Basalts and other mafic crystalline rocks have deeper aquifers too. Already these are being exploited by groundwater bore-wells that are reaching a few hundred meters in many parts of the country as demand for the groundwater increases.

Water in these crystalline rocks is stored and moves along fractures and cracks. Fracture systems in these rock masses penetrate to great depths and must be kept open if the rock is to act as an effective aquifer. The danger is that gas pumped to depths even greater than 1 km may seep up through these deep penetrating fractures depositing carbonate minerals and plugging up the shallow permeability pathways for groundwater.

You could in principle go to very great depths say much more than 2 km, but at some point drilling through the hard crystalline rock will make the project uneconomic.

So then…. if the choice is between pumping CO2 into the crust to economically viable depths to keeping aquifers healthy, then the health of the aquifers must win out. Timely groundwater access improves crop yield and farmer income. The relation is direct and the benefits immediate. Risking reducing the porosity and permeability of these rocks with carbonate minerals to attain a more nebulous benefit (for people who depend on groundwater) of lowered atmospheric CO2 content will be a suicidal course to take and I unfortunately mean that literally. Groundwater irrigates a major share of cultivated areas and access to it offers the best chance of alleviating grinding farmer poverty in face of uncertain rains and lower crop yields due to increased temperatures.

So, no playing around with rock masses under cultivated areas…that might leave sections of the crust underlying wastelands, forests and urban areas as potential sites. Of these wastelands appear as the most promising sites in terms of the least political and civic resistance to such a project. This provided field experiments demonstrate the feasibility of this project and the political and economic conditions allow its implementation.

India’s National Action Plan for Climate Change (15 MB) has very little to say about carbon sequestration. None of the eight missions or strategies meant to deal with climate change include carbon capture and sequestration.

It is under the political radar and it is expensive and India can best mitigate the effects of global warming by keeping the shallow crust fractured and permeable so as to act as an effective aquifer for groundwater.

My feeling is for India at least in the near term this method of preventing atmospheric CO2 buildup is a non-starter.

From Brave Blue Words I found out that Thursday Oct 15  was Blog Action Day for Climate Change. Bloggers all over the world are writing about various aspects of climate change.

Being a geologist I want to point to a study that reconstructs atmospheric CO2 levels as far back as the Miocene  – a 20 million year history. Atmospheric CO2 levels have been reconstructed with some confidence for the last 800,000 years or so using gas bubbles trapped in the Antarctic ice sheets. Before that the data was thin.

Aradhna Tripati and colleagues have used the boron to calcium ratio in foraminifera shells to calculate ancient CO2 levels. As atmospheric CO2 increases some of it diffuses into the ocean increasing the dissolved CO2 content of sea-water. That in turn reduces the amount of boron that is incorporated in a growing calcium carbonate shell of the foraminifer individual. The variation in the boron to calcium ratio over time as recorded in foraminfera fossils of different ages should tell us something about transitions in CO2 levels.

The scientists first validated their calculations using the 800 K record of CO2 trapped in ice. They compared their results with those obtained by the direct measurement of CO2 trapped in gas bubbles. It was a good match. The scientists calculate that the uncertainty in their results is about 14 parts per million.

Their results show that there is a close coupling between CO2 levels, sea-level and temperature over the last 20 million years.  In the middle Miocene (~ 20 ma) CO2 levels were about 400 ppm – comparable to modern levels – and that sea-levels at that time were 30 -40 meters higher than today (geologists estimate this using distribution of ancient shorelines), with temperatures about 3-6 deg C higher (using geochemical proxies like the oxygen isotope composition of shells which depend partly on temperature of the water from which they precipitate). Decreases in CO2 levels in the later part of Miocene and Pliocene were synchronous with major episodes of cooling and glacial expansion.

Its important to establish that historical connection to answer doubts expressed on what exact impact would increasing levels of CO2 have on climate and sea-level. Many climate change doubters are not happy with computer simulations and models of CO2 increase and climate change. This study shows that CO2 has been a strong driver and amplifier of climate change in the deep geological past. History is also a guide and often a reliable one.

Go here for the press release.A minor quibble. The press release calls the shells used by the scientists as belonging to single celled marine algae. Foraminifera are not algae. They are protists.

A second study on these satellite measurements asserts that the groundwater loss amounts to about 54 cubic km per year over a time period of 2002 and 2008. A lot of this extracted groundwater ends up in the sea and could be contributing to raising sea-levels by 0.16 millimeters every year, about 5% of the total sea level rise. That is about the same as contributed by runoff from melting Alaskan glaciers the authors conclude.

I don’t have access to the full paper so I don’t know the details of the calculation but here is what the scientists have to take into account:

Part of the groundwater extracted will be taken up by plants and remain there over the life of the plant and make its way into the food chain.
Part of it will be lost through the plants through evapo-transpiration.
Part of the water will remain in soil adhering to clay and sand particles.
Part of it will make its way back to the aquifer.
Part of it will make its way through the soil to local streams and eventually to the sea.
Part of it will be lost by direct evaporation. That evaporated water (and the water lost by evapo-transpiration) will fall as rain and part of it will infiltrate as groundwater and part of it will be surficial runoff into streams and eventually into the sea.

Just giving you  something to think about what happens to extracted groundwater.

A friend returned from Australia with stories of water rationing in Melbourne and Adelaide. Can’t water lawns and wash cars. That would invite fines from the city. Coincidentally, national geographic magazine has a feature on Australia’s big dry, a prolonged drought that has decimated farming communities in the Murray Darling basin and forced farmers to sell century old farms and move to cities in search of work.

As always I want to steer the conversation to what is happening in India. A recent regional finer grained climate model from researchers at Purdue University confirms what global climate models have been telling us for some time. That monsoon patterns will change both in the timing of the advent of rains and in the amount of precipitation. The map below shows the across-country expected changes in both these parameters.

Source: Purdue

The basic take away lessons from these studies are that: 1) the country will get hotter 2) rainfall pattern will be more unpredictable 3) rains will be concentrated in shorter more intense bursts 4) periods of drought will last longer 5) overall, regions which experience less rainfall can expect even less rainfall, those that experience a lot ofrain can expect little change or an increase in rain.

I turn again to the National Water Mission, one of the eight focus areas in the National Action Plan for Climate Change (15 mb) It does recognize that water availability and rainfall will vary region by region and proposes a host of measures in its draft report that includes enhancement and better management of groundwater resources as well as surface water resources.

That is fine talk but will the resource allocation and effort match the current pattern of water use? Himanshu Thakkar in a detailed critique of the National Action Plan For Climate Change is pessimistic about any fundamental changes taking place in the way the government thinks about water resources. Yet, today over two thirds of arable lands in India are irrigated by groundwater and over 85% of rural water supply and about 50% of urban and industrial water supply comes from groundwater sources. Historically though it is surface water that has received more attention and funding. Our government planners have always been obsessed with mega infra-structure water projects.

Despite hundreds of kilometers of canals, surface water irrigation helps less than 15% of Indian farmlands. The majority rely on direct rain and groundwater supported by about 20 million irrigation wells. It is the small landholders and marginal farmers who benefit most from groundwater. From 1970 to 1995 marginal farms increased their groundwater irrigated areas by 400 percent as compared with just 1 percent increase for large farms, which seem to rely more on canal irrigation.

Looking at the above numbers, at how the water resources pie is divvied up by users, it is groundwater that should be the priority of the National Water Mission. Its not just the lessons from the past regarding the inadequacy of big dams /canals that should guide a shift in focus, but also the realization that climate change will render these systems even more ineffective in the future. Shorter more intense bursts of rain would mean more vigorous surface flow and soil erosion. This would mean increased rates of siltation of canals and dams and a rapid decrease in storage capacity. And a hotter India would mean increased evaporative losses from larger surface reservoirs.

Storing water underground minimizes this loss of water through decreased capacity and evaporation. But a groundwater based strategy faces its own challenges. I am placing below a map of aquifers of India. Compare the spatial distribution of aquifer types with the climate model above.

Source: WHYMAP

Over large tracts of the country, areas that are projected to receive less rainfall in the future are underlain by hydrogeologically complex aquifers!

These are the Precambrian shield areas of south and central India and the Deccan volcanics of central India. In alluvial aquifers which underlie the Indo-Gangetic plains water is stored between sediment grains. There is not a whole lot of spatial variability in water storage properties and although the depth to water table can vary, it is uniform and predictable over large areas. The situation changes in hard rock terrains. Water in these types of crystalline rocks is stored and flows along very restricted zones of permeability. These can be tricky to map. Aquifers are spatially heterogeneous and compartmentalized. Shorter bursts of rain would mean greater surface flow and less seepage underground. That would mean geo-engineering solutions to enhance recharge through careful assessment of recharge zones and use of the 11 million or so dug wells that access aquifers in these hard rock terrains.

If groundwater is to take center stage in our adaptation to climate change geological knowledge will have to play an increasingly important role in how this resource is managed and exploited.

So far aquifer “management” in the few instances it is actually practiced in this country is largely driven by heuristics. But with climate changing and conditions becoming more unpredictable, “this is the way we have done it since our great grandfathers time” may not produce the best results. A more successful approach would be one which uses a more rigorous quantitative understanding of the groundwater systems.

What is the lateral extent and storage capacity of the underlying aquifer? How much water can be sustainably withdrawn from aquifers with particular physical properties? Will certain types of aquifers support certain crop types? We need to improve and enlarge the science programs studying groundwater. Geology comes into the picture in a big way, not just to find groundwater but to manage it as well. That means larger and denser monitoring networks and mathematically inclined geologists to make sense of the incoming data. Geo-engineering solutions to enhance recharge and storage need to be put in place. The increasingly sophisticated understanding of the groundwater systems will have to be explained to the farmers. For that a gentler more transparent interface between geologists and the groundwater user community needs to evolve.

I am not saying anything terribly original here, but scientific management of groundwater is the most economical and environmentally least destructive solution for providing water security to a majority of our farmers.

Now, how do you make the National Water Mission listen?

The volcanic rock basalt underlies the city of Pune and much of the state of Maharashtra. Its rock mass is made up of an interlocking fabric of crystals and it doesn’t have interconnected pore spaces through which water could be transmitted. The permeability of the rock mass is negligible. But basalts can be prolific aquifers. The reason is the various kinds of fractures and joints that serve to store and transmit water.

I came across a construction site near my house the other day and saw that they had dug a pretty deep hole for a foundation. I could see a thick rock profile consisting of two basalt flows. The upper flow was an amygdaloidal vesicular basalt. The lower one was a compact basalt. These are field terms used to categorize flow units with different physical characteristics. At the junction of the two flows was a fractured zone. The fractures were horizontal giving the basalt a sheeted appearance. And water was flowing out of these fractures at a fair pace. Take a look.

Groundwater flow in Basalt

This narrow flow zone which is a few feet thick is really the aquifer in this case. The compact basalt below forms the base of the system. Above this water seep you can see that the amygdaloidal basalt is bone dry. I wrote before about the enormous influence basalt hydrology has on the lives of Maharashtra farmers. You can get an idea why that is so. Finding water in basalts can be tough work because of such narrow permeability zones. Farmers often have the misfortune of farming tiny plots of land over basalts with no or very deep permeability zones. Digging wells into basalts is expensive and risky. Without proper geological guidance many poor farmers remain without access to groundwater.

So far this shallow groundwater system is not being exploited as a resource within the city of Pune. But that might change. Looking twenty years ahead, an expanding population and more water intensive life styles as people become prosperous might strain the surface water supply, which currently is sufficient to give citizens of Pune one of urban India’s highest per day per capita allowance of around 200 liters.

Add to that are the vagaries of the monsoons. Even without global warming induced perturbations to rainfall, Indian monsoons are characterized by a decadal scale natural variability. Pune over the last 3-4 years has experienced higher than average rains but extended periods of lower than average rainfall is also a likely scenario in the future. A combination of lower rainfall and higher population might mean that the surface water reservoirs fall short of supplying enough water. The aquifer underneath Pune might gain importance in this context.

Unfortunately hydrologists don’t really know how much water is present in the aquifers underneath Pune. The state ground water board periodically issues completely useless statements about the level of groundwater either going up or going down by said amounts. These are based on a few observation wells in areas where the aquifer is not being exploited. But there is practically no quantitative assessment of what will happen to the groundwater system if people suddenly start sucking water out of it. The system has not been studied under stress.

There is an opportunity to do that. On the outskirts of the city private water suppliers have sunk dug wells and bore wells. Year after year they are pumping water out of the shallow and deep aquifers. The water balance is not understood. How much should be taken out so that natural recharge will balance extraction? But I don’t see government scientists rushing with their measuring tools to take advantage of these potential data points. Scientific progress relies as much on opportunism as on any other attribute. But state hydrologists lack the flexibility to deviate from their 2 year or 3 year of 5 year plans and schemes they are directed to follow.

Pune must have a science backed plan if and when the time comes to start exploiting the underlying aquifers. The time to start a serious research program is now.

The Himalayas are categorized as having local and shallow aquifers, the Indus-Gangetic plains belong to one homogeneous groundwater basin and the southern peninsular region is a complex hydrogeological province. These are somewhat misleading categories in that they are not mutually exclusive. For example local and shallow aquifers are found all over India. And the Himalayas have plenty of regions of complex hydrogeological structures. But combined with recharge potential the map gives on a broad scale the likely patterns of aquifer yield across the country. 

Looking at Maharashtra I could not help noticing that areas of complex hydrogeological structure and medium to low recharge potential spatially coincided with the vast majority of cases of farmer suicides in the state. This is the region north of Hyderabad and east north east of Bombay. Over the last 6-8 years more than 2000 farmers have committed suicide. The immediate explanation for most of these cases is indebtedness. Farmers borrow money to meet high farming input costs or for other personal reasons and fall into a debt trap if crops fail or give a low yield. The Maharashtra government compiled the results of several studies of farmer suicides and identified conditions that made farmers in these regions particularly vulnerable. These were:

Disruption in regular rainfall cycle since 2001. Long dry spells, deficient monsoon.
Single crop a year, and Cotton the dominant crop. About 70% of farmers who committed suicide had planted cotton.
93 percent of land rain fed. 98 percent of the farmers who committed suicide had no irrigation.
Yield limited by rain, but regular rise in cost of input lowered margin of profit.
Volatility in market price further lowered return.
Commitment to money lender did not leave anything with the farmer.

Farmers are heavily dependent on monsoon rains to water crops. But how does complex hydrogeology figure in this. This agricultural region sits on top of the Deccan basalts. Aquifers are local, shallow, deep, all sorts and show lateral and vertical heterogeneity in their water storage capacity and transmissivity. I have seen this in the field. The situation can change from high yield to bone dry over a distance of tens of meters. So a farmer with a small landholding of a hectare or so – and there are plenty of them in this region- may just have the bad luck of farming on top of an unyielding basalt. He then has to rely entirely on the rains or get into a groundwater sharing agreement with a neighboring farmer who might have a yielding aquifer under his farm. But during times of water stress there is too little water to go around resulting in crop failure or low yields.

Another problem is that not enough attention has been paid to managing the available groundwater resource. Farmers use dug wells as a primary water extraction method but using the dug well to replenish the aquifer during times of good rain is not practiced widely. This has led to aquifer overdraft and a steady diminishing over the years of the groundwater resource. Not all cases of farmer suicide can be linked to water problems. Crops can get wiped out by pests, yields could have been low due to soil degradation, some instances where Bt Cotton seeds failed and then there are probably cases where despite decent yields farmers simply made irresponsible financial commitments. But the link of low yields to ready availability of water is real.

Tushaar Shah a groundwater expert with the International Water Management Institute has made a strong case that focusing on groundwater replenishment will go a long way in preventing crop failure and improving yields. He gives an example:

Over 86 million hectare of India’s rain-fed areas, mid-season or terminal droughts regularly take a toll on the kharif crop. At such times, using around 1000 cubic metres per hectare of water from wells just-in-time to water a wilting crop just once can raise crop yields by 30-230 percent over rain-fed yield levels.

Off course if the wells themselves are dry then there is no backup for failed rains. A Tata Institute of Social Sciences report on farmer suicides found that farmers had little or no groundwater available to them during times of rain failure. A combination of complex hydrogeology and poor management of groundwater resources has exerted a powerful influence on the lives and livelihoods of Maharashtra farmers.

Mr. Shah makes the following recommendation for complex hydrogeological terrains:

What hard-rock India needs is a new mindset of managing dug wells as dual-purpose structures, for taking out water when needed and putting water into the aquifers when the surplus is running off. Recharging aquifers needs to get the first charge on monsoon run off. Unfortunately, government planners give it the last priority.

Water available for recharge is estimated after allowing for the requirements of existing and planned surface reservoirs. This is absurd in a country where 70 percent of irrigated areas and 90 percent of drinking water needs are met from groundwater.

Is the government listening? The Prime Minister of India’s special relief package for Maharashtra farmers wants to attack the problem on a broad front which includes tinkering with the economics of cotton farming, encouraging a diverse array of crops and reducing dependence on pesticides and fertilizers. But water underlies any successful agricultural strategy. In terms of water it lists irrigation development as the only long term solution to the water problems faced by farmers and doles almost 10 times more money to irrigation development than to watershed development. Irrigation development in the language of the government of India means canal irrigation (read mega infrastructure projects) and not local groundwater irrigation.

This despite the revealing statistic that even though thousands of crores of Rupees have been spent on canals, they irrigate just about 15% of arable areas over the landmass of India and marginal farmers and farmers with small landholding benefit most not from canal networks but through groundwater irrigation.

Global warming and changing monsoon patterns is going to be the next challenge to agriculture in the decades to come. Climate models for the Indian subcontinent suggest that monsoons are likely to become stronger although some areas might experience erratic patterns. In May of this y ear, the U.S government released a summary of federal and independent research pointing out region specific impacts of human induced global warming. This was followed by another report on extreme weather and how that may impact different regions in the U.S. We too badly need a thorough region-specific scientific assessment of how global warming will affect different regions in India and use this to plan and execute a massive and focussed effort of aquifer replenishment using existing and new groundwater recharge structures. This is the cheapest and environmentally least destructive solution to improving water security and alleviating farmer poverty.

Following on the heels of my previous post in which I attempted to put up arguments in favor of human induced global warming, a stark and scary reminder of what I am up against. A couple of example of climate change illiteracy I picked up from the blogosphere.

This one is from Climate Progress and an interview with Barb Davis White a republican who is running for the 5Th Congressional District in Minnesota.

WHITE: My name is Barb Davis White and I’m running for the 5Th Congressional District against Keith Ellison for the United States House of Representatives, which is called Congress.

ROMM: Where are you on global warming?

WHITE: Well, global warming really has not been proven. There are 30,000 scientists, including Al Gore’s professor, from Princeton, who says that we are now in a cooling stage. And ev-every — also every other climate that has been warmed had better grapes.

ROMM: So you don’t believe in global warming and you don’t think that people caused it.

WHITE: No, I think global warming is a scam. I think it’s a scam to put taxes — more taxes on us, and it’s called carbon taxes. Our environment has never been so clean, and if we want to push global warming, let’s push it on China, where the smog is so thick that you almost need a helmet to breathe. Let’s push it on Africa and see how they adapt to it, because they’re not going to.

And from Pharyngula who got it from Diatomaceous Earth. A letter sent to the local paper in Fargo, North Dakota. Is Fargo really this eerie?!!

When God sent the rain on this Earth for 40 days and nights, all this water had to go someplace so the Earth would be dry again.

Remember, God is the Creator and controls the universe.

God tilted the Earth from its original position and caused all the excess water to rush to the poles, and there he instantly froze the water into the ice formations that exist today. Time is ticking down on God’s time clock.

With all the nuclear bombs that are made and stored for the fast-emerging last battle, this Earth would burn up when these nuclear bombs are set off.

We are not creating global warming – God is tipping the Earth back to its original position on its axis and thus getting all this ice to get ready to move and extinguish the nuclear destructive fires man will create.

Is this being taught in church or at home.? Where do people learn this? Unbelievable! I have come across the first type of illiteracy i.e. the Barb Davis White type in India, but so far not the second. We can find humor in this but it is a rather depressing example of how a religious fundamentalist education can warp your world view. Have you experienced such extreme views in India?

I learned about climate change in geology classes but that was about changes over geological time, about the Pleistocene ice ages and the Eocene -Paleocene Thermal maxima and the Mesozoic warm period and so on. All these had natural causes but I am persuaded by the collective scientific evidence that humans are causing the earth to warm up and will contribute increasingly to global warming over the next few decades. But if someone asks me a very specific question, let’s say “Can you tell me if there have been errors in the measurement of CO2 recovered from air bubbles trapped in ice”, I won’t be able to answer that.

A few days ago a friend emailed me just such an article which accuses scientists of mishandling, misrepresenting and even deceit in measurements and the presentation of climate data. The article is written by a Polish radiologist and well know climate change skeptic Zbigniew Jaworowski. I read through the article realized that a layperson who is not aware of the data favoring human induced climate change might get persuaded that human induced global warming is a fraud. How should I go about making a convincing case that the article misrepresents climate science?

Can I leave aside the specific questions about ice-core CO2 levels, maybe give references that point to original work and then still make broad arguments that show that Jaworowski himself has made very unreasonable assumptions and omitted important facts and that the scientific data is trustworthy. I am going to try doing that. This is a bit like the evolution-creationism debate. I can’t answer very specific biological questions like maybe how a particular protein evolved but over the years I have gathered broad arguments in favor of evolution. I have persuaded some of my friends using these broad level explanations of evolution and I am hoping I can use the same kind of arguments to explain climate change.

Right. So here is what I came up with. Feel free to add your own insights and suggestions on how to improve such arguments.

1) Combating the conspiracy theory charge: At the outset Jaworowski plays on people’s suspicion of big organizations and huge bureaucracies to imply that the IPCC report on climate change is a political document. He invokes a world wide conspiracy involving the U.N, large global warming research lobbies (which he does not identify) and the U.S government. Yes, the U.S government wanting to politicize climate science to show bias in favor of human induced global warming! This has to be one of the greatest perverse jokes of all. This is a government who for the last 8 years has muzzled its own scientists from presenting the true picture about global warming, has edited scientific reports from its research organizations to convey the impression that the science is still uncertain, and had to be dragged kicking and screaming to admit finally that anthropogenic warming is true. Has Jaworowski been sleeping in a cave?

But is it possible that the report has been manipulated? I have found that many people have the perception that it is the IPCC which was responsible for the science as well. This is simply not true. Research about climate change has been going on for decades in hundreds of labs, universities and research organizations. Scientists have been working on their pet projects, often on very specific topics, sometimes not even asking directly whether humans are causing warming or not. Their research for example may involve improving methods of estimating past atmosphere composition using tree ring data as proxy. As a result we have measurements of past atmosphere CO2 which some other researcher could use to ask a different question. Our understanding of climate change has proceeded by just such hundreds of individual efforts of data collection, measurements and sharing. The IPCC has never commissioned any research. It simply appointed a committee to collate evidence into a report.

2) Meeting charges of deceit and omission head on: Throughout the report Jaworowski accuses scientists of manipulating data, being selective in their presentations and sometimes outright deceit. But I found Jaworowski does pretty much the same. Here is just one example. He says that “It is true that CO2 is the most important anthropogenic [trace] greenhouse gas, but a much more important greenhouse factor is the water naturally present in the atmosphere, which contributes some 95% to the total greenhouse effect.” Now water vapor may be contributing a lot to the total greenhouse effect but this does not explain why the current warming is taking place. The atmosphere is not a homogeneous mixture of gases. It has a layered structure and water vapor is more common in the lower atmosphere. With altitude the atmosphere become drier and colder. The concentration of CO2 is increasing in these high cold drier layers. These layers are absorbing more heat and warming up. The earth is taking in more energy than it is giving out since these cold layers don’t radiate energy much. Eventually though some of that heat radiates back to the lower levels of the earth causing warming.

In an effort to convince that the human contribution to warming is at best negligible he fires the following statistics; 97% of emissions of CO2 in the atmosphere come from natural source, humans account for just 3% of emissions. This 3% of emissions are responsible for just 0.12% of the total greenhouse effect. Again reading the figure 3% and 0.12% is enough to persuade many people that human contributions are at best minimal. But that is not how the figure should be read.

What is important is the carbon budget and exchange of carbon between the three big reservoirs, the ocean, the terrestrial biosphere and the atmosphere. The ocean emits about 330 billion tons of CO2 and reabsorbs a little more than that per year. The terrestrial biosphere emits through organic material decay and plant respiration about 440 billion tons of CO2 but absorbs an equal amount through photosynthesis per year. We know that the oceans are gaining CO2 every year and cannot be a net source of CO2. Ditto for the terrestrial biosphere. Humans emit about 27 billion tons per year out of which about 40% are reabsorbed in the oceanic sink. Which means that the only excess CO2 left in the atmosphere is from human emissions. We know this because we can fingerprint human emissions in a variety of ways. This means the correct question to ask is how much of the increase in atmospheric CO2 observed over the last few decades is due to human activity and the answer is not 3% but 100%.

Jaworowski’s claim that humans are responsible for just 0.12% of the greenhouse effect is also misleading. The earth is at a comfortable livable temperature today due to the building up of the greenhouse effect by natural emissions of greenhouse gases over the past 4 billion years. Humans had nothing to do with this historic building of the greenhouse effect. So naturally our contribution today to the total greenhouse effect is going to be very small. What is worrying is that our CO2 emissions henceforth over the next few decades will be making the majority contribution to the greenhouse effect. I won’t say 100% because future variations in solar radiation may contribute, but our influence on the greenhouse effect is increasing.

95%, 3%, 0.12% all these numbers can easily confuse but they really mean something different than what Jaworowski is letting on. How is that Jaworowski omits these real implications? And what does that say about his credibility?

3) The past is not always a key to the present: A commonly heard argument and one that Jaworowski also uses is that past climatic changes for example the ice ages were triggered not by changing CO2 levels but by changes in solar radiation and so CO2 is not really an important causative factor in climate change. It is true that the Pleistocene ice ages were likely triggered by natural oscillations of solar radiation operating on a Milankovitch frequency of a 100,000 years or so. But that does not mean that CO2 had no role to play in amplifying and maintaining interglacial warm temperatures. This misunderstanding arises primarily because in ice core data, CO2 increase lags the temperature signal by 800-1000 years. Skeptics play on this and claim that therefore historically CO2 has not been an important forcing mechanism for climate change.

Let’s assume that this is true and CO2 had no role to play in the Pleistocene ice age and interglacial warm periods. Does that somehow change the physics of thermal infrared absorption and radiation? If the ice ages were triggered by changes in solar radiation and did not involve the warming effects of CO2 will certain laws of physics become invalid through disuse? Maybe genes can become nonfunctional through disuse but the laws of physics don’t change. The fact is that increases in CO2 in the atmosphere today will inevitable lead to a more potent greenhouse effect. That is just basic physics and it is not influenced by which forcing mechanism controlled past warming. Climate change can take place through a variety of mechanisms. You have to evaluate episodes on a case by case basis.

4) Can we trust scientists? Why do I believe one group of scientists (a large group) and not a loner like Jaworowski? My belief has nothing to do with whether I believe personally in the IPCC or whether I am chummy with some of the scientists or whether I find them to be virtuous honest citizens. What I believe in is the process of science. Scientific ideas are criticized and rethought, data collected and recollected, experiments replicated, instruments re-calibrated when errors are pointed out. The ideas and data we have today about climate change have withstood the test of peer review and elimination. That is why I believe when the vast majority of scientists tell me that humans have and will continue to contribute significantly to global warming.

But Jaworowski and his ilk don’t participate in this free marketplace of ideas. They prefer ambush marketing. Resort to pot-shots at scientists, circulate documents by chain mail over the internet and confuse people with X Files conspiracy theory yarns. Take a look at Jaworowski’s publication record. All in pretty obscure journals and as the caption says “Two of his papers on climate appear on the website of 21st Century Science & Technology magazine!! And I am supposed to believe him over 2 decades of peer reviewed science?

This is all I have for the moment. There are a few other points I have left out regarding past sea-level changes. Maybe I will tackle those in a later post. If you can point to more references and better explanations do leave behind a comment. As I said these are broad explanations for some misleading statements I noticed in Jaworowski’s paper and I am sure climate experts can point out many other problems with his paper. But for now I have a list of references below for some of the specific points regarding climate change.

References:

The gripe that the IPCC report ignores water vapour

The gripe about the lag between CO2 and temperature in ice cores

The gripe about the Mann hockey stick curve

Blog on debunking Jaworowski’s criticism of ice core data

Some more articles about ice core data

More on Human Fingerprints of Global Warming

From my Geology News Feed a link to a pretty cool application for assessing the impact of sea level rise on coastal areas. The application written by Alex Tingle of Firetree.net uses NASA elevation data and the Google Maps API to create dynamic maps of flooding. I played around a little with Mumbai. It’s tempting to run a disaster scenario. Just choose a sea-level rise of 10-15 meters and watch the city go under water. But the results are not very surprising and not too realistic either. This massive a rise in sea level is at the extreme end of the climate change and sea level rise scenarios possible if the Greenland and West Antarctic ice sheet completely melts. May happen but unlikely for the next couple of centuries.

I wanted to find out whether the elevation data underlying the application was fine enough to depict subtle variations in topography and the effect of a small change in sea-level. I used just a 1 meter rise in sea-level. The resulting map impressed. The flooded areas were restricted to the low-lying mudflats and mangroves along the Panvel, Thane, Mahim, Gorai and Vasai Creeks. The rest of the city was unaffected, which is to be expected since the land surface of Mumbai is hilly in places or has been raised by several meters during land reclamation projects. Climate scientists give scenario based range of values for sea-level rise this century and a sea-level rise of 1 meter by the end of the century is a distinct possibility. This would mean large areas of Mumbai and surrounds will be at risk. Image below shows Mumbai and its suburbs and exurbs. Pink areas are the built up concrete jungle, lighter green is land vegetation, blue is water and dark green-brown areas are tidal mudflats and mangroves.

Mumbai City and Environs

A 1 meter sea-level rise will affect these mudflats the most. Yet at places I have marked with arrows near the Panvel and Thane Creeks, pink is intruding upon the dark-green, which means construction is eating up those low-lying areas. All these new constructions are raised a few meters above the original surface and that may protect them against a future sea-level rise. But there are other factors at play and these were demonstrated with terrifying clarity during the flooding by the Mithi river of Bandra-Kurla complex and adjoining low lying areas on July 26-27 2005. As shown by arrows near the Mahim Creek area which trace the Mithi river, mudflats and mangroves were built upon and the river channel reduced to a narrow drain. Since no natural holding areas for the water such as mangroves were left, a combination of high rainfall and high tide led to water level rising up several meters and inundating buildings and even the airport.

But we never seem to understand and learn from history. The same mistakes are being repeated at Panvel and Thane Creeks. When I was growing up, one of the great pleasures of driving to Mumbai from Pune was the gorgeous landscape after Panvel, all those unspoiled tidal channels, creeks and mudflats and mangroves until you crossed the Vasai Bridge. Today that area is an ugly sight. Mud-flats and natural drainages are being filled up and we may soon have constructions coming right up to the banks of the main Panvel tidal channel. The events of July 26 2005 showed how even at present sea-level, bad urban planning can led to severe flooding. The consequences of just one meter rise in sea level can be difficult to predict and may be more damaging than anticipated if you start thinking of its effects on tides and coastal erosion. And add to that are monsoons and storms which may become more powerful as oceans warm up over the century leading to water pileups and storm surges several meters high locally. I really don’t know if the new constructions are being built with future sea-level rise in mind but every time I drive past Panvel all I see is more constructions on those mud-flats. There is no doubt that we are putting the people who will live adjacent to these creeks and channels at a very high risk of flooding and storm damage.