Links: Earthquake Detectives, Origin Of Life, India Water Act

Reading from the past few weeks- 

1) How earthquake scientists solved the mystery of the last “Big One” in the Pacific Northwest. The American northwest is a tectonically active region. About 150 km west of the Pacific coast is the Cascadia subduction zone. Here, the Juan de Fuca, Explorer, and Gorda tectonic plates slide underneath the continental plate of North America. Large earthquakes have occurred in the past and will occur in the future. 

Reporter Gregor Craige has written a book, On Borrowed Time: North America’s Next Big Quake, in which he explores the region's earthquake potential and the cross disciplinary studies that enable scientists to understand past earthquake history as well as the impact a big future earthquake will have. Canadian Geographic has shared an abstract from his book. The earthquake puzzle was solved by combining information from tree rings, Native American peoples memories of past events, and Japanese record of tsunamis. It is fascinating reading. 

2) To unravel the origin of life, treat findings as pieces of a bigger puzzle. Was life's beginnings in a warm little pond or in a deep sea hydrothermal vent? Did lightning provide the energy, did asteroids provide the organic matter? There are many many scenarios that try to provide an explanation to this vexing question. 

One of the leading researchers of this field, Nick Lane, and his colleague Joana Xavier, have summarized some of the key arguments and problems of the field in this tour de force of science writing. Highly recommended! 

3) Analysis: The Great Indian Water Act Of 2024. In more good news for industries, factories and foreign investors, yet another Indian environmental law has been diluted to facilitate “ease of business”. Shailendra Yashwant begins his analysis of The Water Amendment (Pollution and Prevention) Act, 2024 Bill on this depressing note. Amendments seek to "rationalize criminal provisions". Polluters can now escape jail time and get away by just paying a fine. All this when climate change and water security is one of the big challenges facing India. 

W. Bengal Bangladesh- Geologic Controls On Arsenic Distribution In Ground Water

Science writer  Priyanka Pulla has written an excellent article exploring the geologic, socio-economic and technological issues related to the widespread arsenic contamination of groundwater in W. Bengal. Sadly, the government response to this crisis has been slow.

I thought I would elaborate on the geological question -  Why are Arsenic (As) levels much higher in shallower Holocene age aquifers and lower in the deeper Pleistocene age aquifer? The answer encompasses mineralogy, climate change, sea level changes and bacteria.

The ultimate source of As are high Himalayan rocks and Indo-Burman ranges with additional contributions from the Precambrian terrains of Peninsular India and the Siwalik hills.  Minerals like biotite, magnetite, illmenite, olivine, pyroxene, amphiboles contain As. These minerals release As when they undergo weathering in catchment areas and deposits of the alluvial plains. This As is absorbed on secondary minerals like Fe hydroxides like goethite. Such Fe hydroxides are authigenic, i.e. they grow in the shallow buried sediments of the alluvial plains. Under oxidizing conditions, As is immobile, sequestered in Fe hydroxides. However,  conditions may change, and these sediments may get overlain by or be redeposited in environments rich in organic material. Certain bacterial species living on this organic material break down these Fe hydroxides, using the oxygen for their metabolism, and releasing Fe and As into the groundwater. This is known as reductive dissolution of Fe hydroxides and is the principal mechanism for As entering the groundwater in the alluvial plains of Bangladesh and West Bengal.

During the Pleistocene.. 1) the high Himalaya was glaciated. Therefore, important sources of As like the Fe-Mg rich rocks of the Indus ophiolite belt (slices of oceanic crust that existed between India and Asia which have been thrust up during continental collision) and high grade metamorphic rocks such as schists and gneisses were covered in ice and not releasing sediment. Indian cratonic areas, the Siwalik foothills  and the Indo-Burman ranges were being eroded, but overall less As was making its way on to alluvial plains. 2) Since climate was cooler and drier, there was less organic material accumulating in sediment of alluvial plains. Conditions were oxidizing and As remained sequestered in Fe hydroxide minerals. 3) Sea level was much lower then. Almost the entire continental shelf was dry land. Ganga and Brahmaputra met the sea much to the south of present shoreline. Reducing environments like delta front marshes, ponds, estuaries, existed much to the south.

Sedimentary conditions changed by 12-15 thousand years ago. Glacial melt exposed As bearing rocks in high Himalaya. As a result, more As made its way on to alluvial plains. Importantly, sea level rose and flooded the continental shelf. The Pleistocene delta front reducing environments were drowned. Shorelines shifted northwards. The climate was warmer, encouraging vegetation growth. Reducing delta front environments like swamps, coastal marshes and lakes developed on previous alluvial plain sediments.

The map below shows the position of shorelines between 7 thousand and 4 thousand years ago along with the location of wells with high levels of As. This study focuses on Bangladesh but similar conditions existed in West Bengal as well. The sea has receded 2- 3 meters to its present location since 4 thousand years ago.  The delta front and shoreline belt that existed 4-7 thousand years ago is now a densely inhabited region .

 Source: Quaternary shoreline shifting and hydrogeologic influence on the distribution of groundwater arsenic in aquifers of the Bengal Basin- M. Shamsudduha, Ashraf Uddin 2007

Notice clustering of wells with high As along the past shorelines. Here, organic rich delta marshes and swamps developed. Bacterial reduction of Fe hydroxides released As in to groundwater.

As distribution also shows correlation with topography. This map shows high As levels in groundwater coinciding with topographic lows. Such low lying areas accumulate more fine sediment and organic material. Again, this will apply also to W. Bengal.

 Source: Quaternary shoreline shifting and hydrogeologic influence on the distribution of groundwater arsenic in aquifers of the Bengal Basin- M. Shamsudduha, Ashraf Uddin 2007

So, a change in climate and shifts in sedimentary environments in response to changing sea level from Pleistocene to Holocene exerted a strong control on As distribution in the alluvial plains of Bangladesh and W. Bengal. 

Low Emissions Due To Ecofriendly Lifestyles? India's Climate Roadmap

India has submitted its Intended Nationally Determined Contribution to the United Nations Framework Convention on Climate Change. It is a sort of a road map the country will take with regards to future carbon emissions, mitigation and adaptation.

On page two I came across this gem:

Even now, when the per capita emissions of many developed countries vary between 7 to15 metric tonnes, the per capita emissions in India were only about 1.56 metric tonnes in 2010. This is because Indians believe in nature friendly lifestyle and practices rather than its exploitation.

What a load of bollocks!

Anyone familiar with the reality of life in India will recognize this as a specious attempt to explain away the low per capita emissions.

Emissions in India are low not because of nature friendly lifestyles but because of deep poverty. Hundreds of millions of people don't have access to enough energy... and the energy they are forced to exploit like burning cow dung, charcoal, wood and rubbish to sustain themselves is deeply injurious to their health.

On the other end of the spectrum, emissions from the increasingly affluent classes living mostly in cities are beginning to catch up with the developed world.

Nagraj Adve and Ashish Kothari critique the road map. It is not "nature friendly".

Health Impact Study Of India Coal Power Plants

Do check out this New York Times interview with Dr. Sarath Guttikunda on the impact of India's coal power plants on health and environment. Dr. Guttikunda founded Urban Emissions, an air pollution research firm based in New Delhi and is also affiliate associate research professor at the Desert Research Institute, the environmental research arm of the Nevada System of Higher Education. He blogs at Urban Emissions.

Why are such studies important?

From the interview:

From epidemiological studies and the recent Global Burden of Disease assessments, it is evident that outdoor air pollution is one of the key sources of disease and death in India.

In order for the public to demand action on controlling the air pollution, we feel that the information is the key element. We need to know the status of air pollution and contributions from various sources like transport, power plants, industries, household fuels, and others.

We feel that this study is important on two fronts. First, it presents data on emissions, concentrations and health impacts of the coal power sector. While this may seem basic, it is unfortunate that this sort of information has not been published previously and we hope that it presents policy makers with evidence as to air pollution and health impacts of the sector. Second, it shows that despite the air pollution it causes, there are minimal regulations in place to address the air pollution impacts.

If the study convinces policy makers of the need to put in place stringent standards and enforce them – then it may be a start to a broader conversation on our energy needs and the environmental and health costs of supplying them.

111 coal plants currently meeting about 60% of our electricity needs, but around 455 new ones planned according to the World Resources Institute.  Dr. Guttikunda says that with so many new plants a mere tightening of emission standards may not be sufficient to negate the health impacts of these plants. An alternate cleaner energy source needs to be available in really large amounts to avoid building so many new coal plants.

Nuclear power.... natural gas... solar... wind..?  There will be no silver bullet solution to India's energy needs.  We'll have to end up using an energy mix. That will include coal for several decades at least.

Florida Sinkholes Also Pose A More Subtle Danger

Last week, a fatality, as the ground gave way under a Tampa Bay area home.  However, the more common concern regarding sinkholes is their connection to groundwater quality. Despite its reputation as a great tourist destination, Florida is also a major agricultural state. The soil is reenforced with fertilizers, and crops are sprayed extensively with pesticides. Environmental managers worry that these chemicals might find their way into groundwater.

This concern is not unique to Florida but is amplified due to the presence of karst topography.  Extensive limestone formations underlie Florida. Limestone reacts with the weakly acidic groundwater and over the last few million years these limestone beds have dissolved away in varying degree to create an underground network of caves and pipes. The overlying strata may bear its own weight for long periods depending on how thick it is and how porous the underground limestone has become, but occasionally the cover collapses into the underlying cavity forming surface craters or sinkholes.

Fatalities are rare, but sinkhole formation is quite common over geological time.  The map below shows an area just east of Gainsville.

Notice the circular and irregular shaped lakes. Most of them are sinkholes now filled with water. This surface water makes its way through fractures and pipes into the underlying limestone which make up the Floridan aquifer system. Sinkholes thus provide a direct and quick connection for potential pollutants to contaminate groundwater which is the main source of drinking water in Florida.

Isolating Nuclear Waste At Yucca Mountain

BLDGBLOG has an interview with Abraham Van Luik, a geoscientist with the U.S. Department of Energy.

Its a long interview about isolating nuclear waste. Yucca mountain and its geology feature prominently.

Definitely worth reading.

That's Why North Indians Cough More

A stunning image of north India taken by the the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Image was taken on October 30 2008.



Source: NASA Earth Observatory

The haze seen has many causes. Urban pollution, big fires (red dots) and small fires lit for cooking and maybe a sandstorm. Is this worse than Los Angeles at its worst? With winter setting in the northern parts of the country the air quality will deteriorate even further as millions of charcoal and wood fires are lit for warmth. Respiratory problems increase dramatically in the winter in north India.

India faces a frightening challenge of improving air quality both in urban and in rural settings where indoor pollution is a major health hazard. The government has launched the National Action Plan for Climate Change (15 Mb) with separate missions aimed at providing clean energy. Even with a sense of urgency it will likely take a couple of decades to unfold. In the meantime how do you provide alternatives to ten's of millions of people who light up coal and wood fires inside their houses? The National Action Plan besides its focus on large scale clean power generation, urban pollution, sea-level rise and so on, must also provide strong incentives to companies involved in producing low-cost clean energy solutions for rural India.

Transport Options for Indian Cities

The city of Muenster, Germany has this message for urban transport planners in India:


I got this from Tim Harford's blog who got it here. Despite the quibbling over camera zoom and angle and whether the picture depicts transport patterns realistically, I think the poster makes a great point. The city compares the space used by various modes of transport in moving a comparable number of people. Here are the stats for moving 72 people

Bicycle: 72 people are transported on 72 bikes, which requires 90 square meters.

Car: Based on an average occupancy of 1.2 people per car, 60 cars are needed to transport 72 people, which takes 1,000 square meters.

Bus: 72 people can be transported on 1 bus, which only requires 30 square meters of space.

Besides space occupied there is also the problem of pollution. Bicycles don't emit pollutants and buses pollute less per passenger km traveled than other motorized transport. Yet currently we tax private vehicles less than public transport buses creating distorted incentives for vehicle choice. The various taxes that favor private vehicles more than bus public transport are nicely summarized in this letter from the Centre for Science and Environment to finance minister P. Chidambaram.

Orissa and Hexavalent Chromium

A list of the most polluted places on earth prepared by Blacksmith Institute, an environmental group appeared in the Times of India, a few days ago. Not surprisingly it included two sites from India; Vapi in Gujarath state and Sukinda in Orissa state. Pollution in Vapi was mostly due to the chemical industry while that in Sukinda has a geological origin, the mining of chromite deposits. Sukinda mines account for a staggering 97% of discovered chromium ore deposits in India. Why is Orissa so unusually blessed or cursed some would say with chromite?

Chromite deposits form by a process of concentration by crystallization in magmas. But not just any magmas. Chromites are almost exclusively restricted to ultramafics, magmas rich in magnesium and iron. Chromite deposits occur in two varieties known as stratiform and podiform. As the terms imply, stratiform means layers of concentrated chromite within the ultramafic rocks, while podiform chromite occurs as lenses or pods of concentrated chromite within the ultramafics. The Sukinda chromites are stratiform. During the late Archean- early Proterozoic period around 2.5 to 2 billion years ago geologists estimate, massive amounts of ultramafic magmas originating in the mantle were injected into the crust in the area that is now Orissa. But why is chromium so concentrated in ultramafic magmas? Chromium is a refractory metal i.e. a metal with a melting point higher than iron and cobalt. It takes a large amount of melting in the mantle to release significant amounts of chromium in to the liquid phase. But large amounts of melting also make the magmas rich in magnesium and iron. So the connection of chromium and chromite deposits with ultramafic rocks.

Stratiform and podiform chromite deposits occur in distinctive tectonic settings. Stratiform deposits occur mostly within ultramafic intrusions in stable continental crust, while most podiform deposits originated in oceanic settings, either within ultramafic rocks associated with mid-oceanic spreading centres or in subduction zone associated back-arc spreading centres. Later, plate tectonic movements have obducted or thrust up these chromite bearing ultramafics to form sections of spectacular mountain belts. The best example in India are the podiform chromites in Ladakh (Karmalkar N.R. et al. 2000), which originated in the oceanic crust between the Indian and Asian continents in the Mesozoic period, and were subsequently thrust up to form the early Himalayan mountains as the Indian plate collided with the Asian plate.

Chromite deposits show an interesting age distribution indicative of the thermal and tectonic evolution of the earth.

Image Source : Stowe (1994). Stratiform deposits occur almost exclusively in the late Archean-early Proterozoic period (2.8 - 1.8 billion years ago), while podiform deposits occur almost exclusively in the Mesozoic and Tertiary periods beginning around 200 million years ago (there are some podiform chromites in late Proterozoic orogenic belts around 800 million years old). Anyone familiar with the geological time scale with readily appreciate that biological evolution has imparted a temporal uniqueness to the sedimentary rock record, enabling geologists to subdivide geologic history into different periods. What is less appreciated is that the thermal and tectonic evolution of the earth has also produced a distinctive rock record (a good idea for a post series). Chromite deposits are one good example. The mid late Archean-early Proterozoic was a period of intense continental crust building. Owing to the high geothermal gradients in the Archean (the interior of the earth was hotter then), there were periods of copious amounts of melting in the upper mantle and lower parts of earlier formed crust. So, were formed large ultramafic complexes and associated chromites. Over time, the earth cooled and large scale melting of the mantle became localized to plate boundaries. The breakup of supercontinent Pangea beginning in the early Mesozoic led to significant worldwide development of subduction zones and associated back-arc spreading centres and the origin of ultramafic hosted chromite. This activity culminated in intense amounts of mountain building activity in the mid-Mesozoic and early Cenozoic. So, podiform chromites occur mainly within tectonically emplaced slices of oceanic rock sequences in this age group. The gap between around 800 million years to 200 million years is one of geology's unresolved problems.

Chromium from Sukinda mines is present as air-borne dust and is also being leached into the groundwater and nearby streams in the form of hexavalent chromium (+6 oxidation state).

In image, the Sukinda syncline is clearly seen. In the core of the syncline the arrow points to the open pit Sukinda chromite mines. The rust color is due to oxidation of the ore. When ingested either through air-borne dust or through water, hexavalent chromium is reduced in our cells to pentavalent and trivalent chromium. This leads to a variety of health problems, including increased risk of cancer. An estimated two hundred and seventy thousand people around Sukinda are at risk or are suffering from chromium related poisoning. The Orissa Pollution Control Board have pleaded impotence, saying “It is unique, it is gigantic and it is beyond the means and purview of the (Orissa Pollution Control) Board to solve the problem,”. In effect they have questioned the rationale for their own existence. The board chairman L.N. Patnaik has predictably rubbished the report, saying that any mining activity will lead to some air pollution, apparently forgetting that chromium is getting into the water supply in massive quantities.

Hexavalent chromium gained recognition because of the movie Erin Brockovic, in which the character played by Julia Roberts campaigned successfully against a polluting industry. In India, maybe this lady on the left can help :-)


References:
Karmalkar N.R., A. G. Dessai and R. A. Duraiswami: Alteration of Chromite from the Dunites of Indus Ophiolite Belt, Ladakh 27-34, Himalaya, India, Gondwana Geological Magazine; V. 15 (1)- June 2000

Stowe, C. W. 1994. Compositions and tectonic settings of chromite deposits through time. Econ. Geol. 89:528 – 546

Urban Forests and Clean Air

Part 4 of the six part series on Pune city pollution and environment. Updated every Tuesday.

Tropical forests are extremely important to the global carbon cycle. These forests remove a high proportion of carbon dioxide being emitted by industries and through deforestation. Human activities emit around 25 billion tons of carbon dioxide (CO2) every year. Out of that about 30% is absorbed by the oceans, about 40% stays in the atmosphere and about 30% is thought to be absorbed by forests. Temperate forests are less efficient in sucking in CO2 as compared with tropical forests. But the amount of forest cover is steadily decreasing thus increasing the amount of CO2 that stays in the atmosphere. Deforestation is the second biggest emitter of CO2 after power generation as can be seen in the figure below on greenhouse gas emissions by source (source: World Resources Institute).


In general mature forests are not net absorbers of CO2, since they give up almost as much CO2 through rotting biomass. New growth forests are more efficient absorbers of CO2. So planting trees and expanding forest cover rather than just maintaining forests will lead to offsetting of CO2 emissions.

Right on! Trees as life givers of oxygen (I often wonder why people don't choke to death in deserts), trees as the lungs of our city, save trees and breathe better, all these have become popular slogans. Here are a few more from Pune environmentalists:

"The veritable and venerable lungs of our city".. in this article

"..these green areas give Oxygen....(for us humans..and this is the only source of Oxygen on the planet), help to reduce pollution, and preserve our eco-environment" in this article

and recently (Times of India, Sept 13 07, Pune) by noted environmentalist Anita Gokhale Benninger " An average Pune family size of five people will require 60 sq metres of green areas to breathe and survive. Once preserved and re-forested, the Pune BDP (biodiversity parks) will provide clean air for approximately 35 lakh (3.5 million) people living in this area"

The ability of trees to absorb CO2 has lead to an unquestioned faith in their ability to provide us with clean air. But can trees provide us with that service?

Let's take pollutants that harm us now, and pollutants that will harm us in the future.

Vehicles in Pune emit several hundred to thousands of tons of harmful pollutants like SOx, NOx, HC and PM10 (particulate matter) every year. These are having immediate health effects on citizens. But trees do not absorb these chemicals. No amount of tree plantations will have any effect on the amounts of these pollutants in the air. Ultimately only better quality fuel and to a certain extent a better public transport system will have any appreciable impact on Pune air quality. But trees also absorb dust. Won't that reduce for example the amounts of particulate matter. Ms. Benninger recently calculated that trees in the proposed biodiversity parks will trap around 80 thousand tons of dust per year. The problem is that a large proportion of particulate matter that harms citizens is adsorbed on dust lying of unclean and unpaved roads. Pune Municipal Corporation Env. Status report 2006-07 indicates that nearly 6 thousand tons of particulate matter adsorbed on dusty roads get suspended by vehicular traffic. This is the dust that harms citizens health. The solution for this problem is not trees on hills but better paved roads which are cleaned regularly.

And what about pollutants like CO2, which through its effect on global warming will harm us in the near future? Is the tree cover in Pune offsetting sufficient amounts of CO2 emitted from vehicles? The discrepancy is startling. Here are two examples:

The forest cover on Law College Hill and Vetal Tekdi absorbs about 1.5 tons of CO2 per year. In contrast, idling your vehicle for 5 minutes at Nal Stop every day, will lead to emission of about 625 tons of CO2 per year (amount calculated for total number of vehicles passing through Nal Stop every year).

The total amount of CO2 absorbed by the tree cover in Pune is about 55 thousand tons per year. In contrast, vehicles emit about 2 million tons of CO2 per year.

So Pune tree cover cannot save us from the increasing amount of CO2 emissions either. Increased plantations especially on the hills will help increase the amounts of CO2 absorbed, but I feel they will play no significant role in offsetting vehicular emissions.

Image below shows managed forest on Pune hills.

The second topic I want to briefly touch on is the reporting on the proposed biodiversity parks on the hills. There are complex legal issues involved in this since the ownership of the hills is split between the forest department, the government and private land owners. A significant portions of the hills have been encroached upon by slums. Recently from an environmental perspective the reporting has focused upon carbon trading schemes and whether they can generate funds for land acquisition. The basic idea is to use plantations on Pune hills to offset CO2 emissions and get paid for every ton of CO2 absorbed. Supporters of this scheme say that significant amounts of funds can be generated by plantations on Pune hills. Here is a summary of a recent calculation by Ms. Benninger (Times of India, Sept 13, 07, Pune):

The amount of hill land is 1646.74 hectares. Each forest hectare will absorb around 55 tons of carbon per year. Therefore the total amount of carbon absorbed per year will be 90,530 tons. Carbon credits are presently sold for around $12 per ton of CO2 eq. (my link) and will increase in the near future. So amount of funds generated per year will be around 4.88 crore.

First some technicalities. Some of the hill land is already built upon legally and will in reality never be available for any plantations. Further, is it 55 tons of carbon or carbon dioxide? If it is carbon that means almost 200 tons of CO2 will be absorbed per forest hectare per year (one ton Carbon combines with oxygen to give 3.62 tons CO2). Either way, 55 tons absorption of carbon or carbon dioxide is a gross exaggeration (doesn't the media ever do any background checks?). Amount of CO2 absorbed per forest hectare varies depending on the climate (temperate or tropical) , soil quality, and species of trees. Generally the range is from about 6 tons per year for temperate areas to anywhere from 5 tons to 20 tons per year for tropical areas.

All these amounts are for managed plantations. Currently our forest on various hills (few hundred hectares) are absorbing in totality around 3-4 tons of CO2 per year. This is an abysmally low figure but not very surprising if you are to walk on these hills. The vegetation is stunted and sparse. It sheds leaves starting December and lies bare until the monsoons. By February the forest department starts burning the underbrush as part of their forest management plan. This means emissions of CO2. I doubt if there is any net absorption of CO2 by these forests, especially in the more mature stands. Considering the rocky soils of the hills, no amounts of additional plantations will raise CO2 absorption to a quantity that can generate any significant funds. Besides, environmentalists agree that even the dubious 4.88 crore per year they have calculated is too little an amount for land acquisition, which will require according to estimates several 100 crores.

On this funding issue, the Maharashtra government has been disingenuous. They have transferred the burden of coming up with the funds for the biodiversity parks onto the Pune Municipal Corporation and are refusing to pass the green development plan for the city, which has earmarked the hill areas as biodiversity zones. However, large amounts of money which will unlock land on the hills especially through slum rehabilitation is tied to the Jawaharlal Nehru National Urban Renewal Mission, a central government scheme to modernize Indian cities. The centre will not release that money to the Maharashtra government until they repel the Urban Land Ceiling Act , which the Maharashtra government is hesitating to do. That really should be the thrust of the arguments made by the PMC and environmentalists in the effort to acquire land for the biodiversity parks.

In summary, regarding the biodiversity parks, I feel carbon trading schemes will not generate any appreciable funds. Besides, the very nature of carbon trading schemes through plantations is incompatible with what should be the real goal of the biodiversity parks, which is maintaining and expanding biodiversity. Trading schemes require that plantations consist of rapidly growing trees. Even though indigenous species will be preferred, it would inevitably mean that the plantations will consist of only one or two rapidly growing indigenous tree species, defeating the purpose of developing and maintaining biodiversity.

Trees on Pune hills will not provide citizens with clean air nor will they significantly offset CO2 emissions. The real value of urban forests on these hills is that they provide citizens with open recreational areas, and if properly developed will create expanded habitats for land animal and bird species, thus genuinely contributing to rich urban biodiversity. That by itself is a goal worth fighting for.

Part1. Idling and Pollution
Part2. PMT buses and Pollution
Part3. Rickshaws and Pollution

Rickshaws and Vehicular Pollution

Part 3 of a six part series on Pune city pollution and environment. Updated every Tuesday.

Didn't you see my right foot?! In the middle of an argument over a minor accident the rickshaw driver claimed he had poked his right foot out to indicate that he was turning right. Pune has around 60-70 thousand three wheeler rickshaws. They are no doubt a very convenient form of taxi service. To many harried customers, rickshaw drivers are rude and indisciplined, but I don't really find their behavior on the road to be any different than that of private vehicle owners. This is a country where everyone owns a piece of the road, so rules be damned.

But rickshaws do pollute a lot. Below table shows pollution amounts in tons/year for different pollutants for a total of 62, 600 rickshaws, compared with other vehicle types. Source: Emission factors from S. Guttikunda, World Bank. Rickshaw numbers from N. Iyer, Consultant Bajaj Auto. Values represent combined sum for two stroke and four stroke rickshaws. Other vehicle numbers, from Pune Municipal Corporation, Env. Status report 2005.

As I showed in my previous post, buses pollute more on an absolute basis but are more fuel efficient on a per passenger km basis. What about rickshaws? Below graph shows per passenger km pollution for a trip of 100 kms. It shows that rickshaws pollute more than buses and two wheelers on a per passenger km basis.

Source: Emission factors for CO2, PM10 and SOx from World Bank: A Simple Model for Better Air Quality (2005); N.Harshadeep and S. Guttikunda. Emission factors for rickshaw, S. Guttikunda and N. Iyer.
Assumed Occupancy: 2 wheels-1, Car-2, Bus- 40, rickshaw - 2.

To tackle rickshaw pollution, the Road Transport Authority has made a policy decision to convert existing 2 stroke and 4 stroke petrol rickshaws to natural gas powered vehicles. How much reductions in emissions will be achieved by conversion of petrol rickshaws to CNG? (compressed natural gas). Below table shows reduction in emissions in tons/year for rickshaw and for comparison reduction in emission for PMT buses.

Blank fields indicate lack of data for emission factors. However, SOx emissions are expected to decrease by large amounts for CNG rickshaws.

A conversion of existing fleet of 2 stroke and 4 stroke rickshaws to CNG has the potential to reduce CO and HC emissions by around 95 percent and PM emissions by around 40 percent! There would be significant reduction in CO2 (by about 30,000 ton/yr, or about 20%). Public transport contributes to a substantial portion of total vehicular pollution. My admittedly rough estimates suggest that public transport including rickshaw, PMT buses and private company buses (about 8000 of them according to the municipal corporation) contribute about 40% of total SOx emissions, 30% of PM10 emissions and about 35% of CO2 emissions. Conversion to cleaner fuels will definitely lead to improvements in air quality, especially if the several thousand private company buses are also included. But changing fuel quality of public transport alone may not help in the long run. In Delhi, after significant improvements in air quality due to conversion of public transport to CNG, the latest news is that pollution is on the rise again, due to a heavy influx of private vehicles, many of them running on diesel. Pune faces similar problems with about 6000 new vehicles being registered every month. And with the eminent arrival of the much touted 1 lakh rupee car in the next few years, gains in reducing emissions by cleaner fuels in public transport vehicles may be swamped by the enormous increase in private vehicles. A more comprehensive public transport system needs to be pursued with urgency combined with pricing initiatives to make driving private vehicles more expensive.

Finally some thoughts on six seater rickshaws, those horrendous contraptions, which were banished to the outskirts of the city, because they were thought to be "polluting more". Image shows a six seater in Pune suburbs.

I have to admit I have a liking for these beasts. There is no doubt that they offered frequent and cheap transport services, something that the bus transport has failed to offer. In principle they should not pollute more than rickshaws, maybe even less on a per passenger basis, since on average they carry more passengers. But a widespread use of adulterated fuel and very poor engine maintenance has lead to additional pollution. Here's a thought. Why doesn't the PMT offer their own six seater service? Is it necessary that they offer only a bus service? This way at least the fuel quality can be regulated, and drivers can be trained to obey at least a few rules.

But that would mean thinking out of the box!

Part 1. Idling and Pollution
Part 2. PMT buses and Pollution

PMT Buses and Pollution

Part 2 of a six part series on Pune City pollution and environment. Updated every Tuesday.

New Delhi, Asian Games 1982. I have memories of broad, clean avenues and clean air. When I returned after a long gap in 1999, New Delhi was urban hell. My friend pointed out a particularly busy intersection and said, "that's the most polluted intersection in Asia". I went back in 2004, and something strange had happened. Something we Indians are not used to. Pollution had reduced dramatically. Air quality was better. The reason experts tell us, was the conversion of almost the entire public transport fleet (15-20 thousand vehicles by various estimates) of rickshaws, taxis and buses from diesel to CNG (Edit: Compressed Natural Gas).

How much will Pune Municipal Transport (PMT) benefit from a conversion from Diesel to CNG? Graph below shows the potential in reducing emissions (tons/year) by converting the current Pune Bus Fleet of 990 buses (PMT plus rental) from Diesel to CNG. (for the purpose of the calculation I have assumed all 990 buses are on the road everyday, which given the state of disrepair of PMT buses may not be the case).

Source: Emission factors for CO2,PM10 and SOx from World Bank: A Simple Model for Better Air Quality (2005); N.Harshadeep and S. Guttikunda. Bus operating kms per day, PMC Env. Status Report, 2005.

A CNG fleet will lower emissions of PM10 (particulate matter) from 135 tons/year to about 40 tons/year (70% reduction), of SOx from 80 tons/yr to about 25 tons/yr (68% reduction) and CO2 from about 65 thousand tons/yr to about 35 thousand tons/yr (46% reduction). There are considerable (about 50%) reductions in nitrogen compounds as well, but I did not have the emission factors available to make any specific calculations. But what about methane? CNG is about 80% methane, which is 20 times more potent a greenhouse gas than CO2. Won't the higher methane emissions offset the lower CO2 emissions? Apparently if one considers the total fuel cycles of diesel and CNG including emissions during fuel production, CNG buses have total greenhouse gas emissions similar to diesel buses. Diesel also emits toxic compounds like polyaromatic hydrocarbons, benzene and 1,3 butadiene that CNG does not.

How does bus pollution compare with other vehicles? Although Diesel or CNG buses may emit more pollutants than a 2 wheeler or car in an absolute sense, are they at least more efficient on a per passenger km basis considering they carry more passengers per trip? Graph below shows the emission of pollutants per passenger km, if a commuter makes a daily trip of 30 kms to and from work. The calculations show that even on a per passenger km basis Diesel buses emit more particulate matter than 2 wheelers. CNG however on a passenger km basis is much cleaner than petrol and diesel vehicles.

Source: Emission factors for CO2, PM10 and SOx from World Bank: A Simple Model for Better Air Quality (2005); N.Harshadeep and S. Guttikunda.
Assumed Occupancy: 2 wheels-1, Car-2, Bus- 40

To summarize, conversion of PMT buses to CNG will definitely benefit the city. An even bigger reduction in emissions would be achieved through the conversion of several thousand private buses. There is a move to convert the fleet of rickshaws to LPG/CNG. More on that in another blog.

As fuel costs keep increasing, public transport will increasingly be the more cost effective means of transport. Below graph shows Per Km Petrol Cost for Two Wheelers vs Bus Fare Cost per passenger km

Source: Central Institute of Road Transport

The trend indicates that due to increase in petrol prices, public transport per passenger km is increasingly a more efficient mode of transport than private vehicles.

Be sure to read about CNG facts and myths in this fact sheet from the Centre for Science and Environment in Delhi and also about CNG buses and how they compare with Diesel in this fact sheet from the U.S. Dept. Of Energy.

Part 1. Idling and Pollution

An Idle Threat

Part 1 of a five part series on Pune City and environment. Updated every Tuesday.

I cross Law college road everyday on my way to soccer practice. The traffic is an endless stream, and sometime back I told the other coaches that I will be coaching from the other side of the road. At the Prabhat road signal and at Nul stop the back-up is so bad, you could easily miss 3 or even 4 signals before crossing the intersection. Urban legends about these backups are growing. Just last week a woman gave birth in her car waiting for the signal. Most vehicles keep their engines idling during their wait. That gave me the idea for this blog. How much pollutants does your vehicle emit when you wait for a few minutes at a traffic signal? How much does the entire city of Pune emit?

I first had an inkling that the amounts were big when I noticed at truck stops in the U.S. that the truckers never shut down their engines. A little web research told me this astonishing fact:

Trucks in the United States consume about 1 billion gallons of diesel annually while idling! This amounts to about 11 million tons of CO2 emitted annually (Source: U.S. Dept. of Transportation). Overall the transport system in the U.S consumes 8.4 billion gallons of fuel annually while idling. This amount to about 83 million tons of CO2 emitted annually while idling.

Edit: Based on EPA chemistry of fuel combustion 1 billion gallons will emit about 10.1 million tonnes of CO2, but the EPA warns that "calculations and the supporting data have associated variation and uncertainty".

Using vehicle numbers from the Pune Municipal Corporation Env. Status Report, emission factors for various pollutants from a World Bank study and some assumptions about mileage and idling times I did some calculations for Pune. The numbers do not give any comfort.

On a daily basis, assuming a vehicle idles for just 2 minutes every day:

The total fuel consumed in Pune by idling cars, two wheelers and rickshaws amounts to an incredible 19 thousand litres per day! Emissions of greenhouse gases amount to 45 tonnes/day.

How much do all of us on an individual basis contribute? Graphs below estimates how much fuel is consumed and how much CO2, PM10 and SOx is emitted by your vehicle every year if you idle your engine for just 2 minutes every day waiting for the light to turn green.

So, if you drive a regular car you probably lose about Rs 500/- or so yearly on fuel burnt while idling. This 2 minutes is a very conservative estimate I used to do the calculations. Idling time may well be much more. For example, idling your car for 5 minutes every day, you will spend about Rs 1250 per year in fuel burnt and so on. Something to think about next time you are waiting for the light to turn green at a busy intersection. How do you make people change their habits? One way is to appeal to their civic sense, and the other in my opinion the more effective, is to make them aware of the costs of their behavior.

See, where I am going with this? If I alone spend Rs 500/- how much for the entire city? Table below shows how much the city of Pune is paying yearly in terms of fuel lost, CO2, PM10 and SOx emitted, and fuel cost for vehicle idling. This is for total number of cars, two wheelers and rickshaws in Pune, assuming an idling time of 2 minutes every day.









For readers outside India, 1 crore = 10 million, so Pune city spends Rs 34 crore or Rs 340 million worth of fuel burnt while idling. If all vehicles in Pune reduce idling time by just one minute per day we would save about 3.4 million litres of fuel worth about Rs. 17 crore annually! This is equivalent - in terms of fuel saved and CO2 emitted - to removing around 18,500 two wheelers or about 9,300 cars from the roads of Pune.

By the way, you can learn more about idling and various myths using this website from the Canadian Office of Energy Efficiency, designed specifically to help individuals, communities, businesses reduce vehicle idling and pollution.