Political, Religious, Literary, Economic, Bangladesh, International, Life as it is, Cultural

Cultural and National Identity

Most of us have differed often enough with one another on what precisely constitutes culture. That is hardly surprising in view of the fact that it is common for even erudite philosophers to disagree and debate with each other on the raw definition and nuances of culture. The way we perceive culture is very much a mirror of our philosophy in life and of our view of the society we live in. It is but natural that we differ. But does it really make any material difference to a society on what exactly a culture is or on what a particular cultural guru enforces the cultural attributes of a society at a particular point in time and space?

Culture is more like the free-flowing water in a river. It takes on the colour of the alluvium soil it flows over at any particular moment. Culture of a people is anything but static; it changes, it merges, it meanders, it evolves like the life on earth.

The so-called Calcutta Book Fair fiasco had prompted certain coteries of vested interest to make mountain out of a mole hill. At the forefront was the Bangladesh Nationalist Party (BNP) which had donned the mantle of the keeper of Muslim Bengali culture. It had self-proclaimed the distinctiveness of Muslims to create a separate identity for Bangladeshi culture.

The party was founded by a freedom fighter who fought for the liberation of Bangladesh or Bangla nation. But the Kakul trained former Pakistani army officer who spoke Bangla with a distinct Urdu accent, due to his long stay in the western wing of Pakistan, ultimately took on the role of a Trojan Horse. When he assumed the charge of independent Bangladesh in the aftermath of a series of coup d’etats and assassinations (which many people claim may have been through his acquiescence), he took upon himself the task of rebuilding the nation in the model of “Pakistan.” Thereby, he failed to live up to his glorious deeds during the days of blood and thunder. The unholy coalition that he forged with the religious right had made him to rehabilitate those hated anti-Bangladeshi forces in the independent Bangladesh. It brought back the ghost of Pakistani oppression in Bangladesh.

The Bengalis in Pakistan had made sacrifices to found a modern state based on secular ideology. The Sufi tradition had deeply influenced the Islam in Bengal. Its tolerant ethos was a far cry from the religious intolerance of West Pakistan that would later spawn into Taliban movement.

The Bangladesh Liberation War was a struggle against the hard-line exclusivist tradition of West Pakistan that was trying to supplant the liberal tradition of the eastern wing and turn it effectively into a colony. Under the guidance of the Pakistani junta from the west, the Islamist parties made it their goal to eliminate religious minorities and to discard the secularist strands from the composite culture of Bangladesh. They cried “Islam is in danger.” to garner supporters for their invidious goals.

It was a national goal in certain quarters during the Pakistani era to erect a psychological barrier between West Bengal and East Bengal in the guise of championing the cause of Islam. There was a crack in that barrier for a brief period during 1971-75. But, after 1975, for the next two decades, that barrier was restructured and reinforced to mirror the prejudices and predilections of the past. The master architects of that barrier were the Pakistan trained officers of the Bangladesh army who continued to look back to the pre-liberation days towards Islamabad for political inspiration.

The balance of power in Bengal in the era of Permanent Settlement had indeed tilted disproportionately in favour of the Hindus. The 1947 partition did serve to restore the balance. But it can just as easily be argued that East Bengal got rid of the over-lordship of the local Hindu zamindars only to embrace the colonial shackles of West Pakistan. Furthermore, it was demanded by its new masters to sever all ties with “Hindu” West Bengal with which it shared many common cultural heritage and where at least a quarter of the population was Muslim.

The Bangabhumi of yore was today’s East Bengal. It had always been the core of Bengali language and culture. West Bengal was the Rarhbhumi which was part of Greater Bengal and had, till the coming of the British, looked up to East Bengal for cultural inspiration and sustenance. So, in a sense, Bengal’s cultural heritage had its root in East Bengal. The proponents of Bangladeshi nationalism had their own agenda. It was to erase West Bengal from the canvas of Greater Bengal with a view to turning Bangladesh into a puppet in the hands of Islamabad’s rulers, who would only be too happy to use Bangladesh as the cat’s paw to further their own interests.

Then there were those who had vested interests in declaring, “Hindus of West Bengal and Muslims of Bangladesh are two distinct peoples; they have absolutely nothing in common” Inevitably, proponents of this delinquent ideology ignore the cultural affinities of West and East Bengal to emphasise only on religious differences. That was the only way they could erect a barrier between the two Bengals. But even that was not easy because a quarter of West Bengal’s population was Muslim. Would the religious fanatics disown Poet Nazrul Islam because he was from West Bengal?

There are some differences between the inhabitants of the two Bengals. But it is not simple to cut off West Bengal from our cultural canvas on the basis of these differences. Religion, ethnicity, dialect, and regional characteristics, all play an important role in defining our cultural ethos. It is as disingenuous as it is dishonest to try to define it in terms of religion alone.

Consider the regional component, for example. The immigrants in Calcutta from East Bengal, from long before the 1947 partition, had indulged in their regional pride by cheering for the East Bengal team on Calcutta’s football fields. And to this day they continue to do so. It pleases them no end when East Bengal defeats Mohan Bagan. The Islamists in Bangladesh
will be hard put to explain this exultation in the football fields of Calcutta in terms of their mindset of seeing everything with religious lens.

Region-based differences indeed seems far more significant than religion-based ones. A Muslim Bengali from West Bengal is likely to feel more at home with a Hindu Bengali from West Bengal than with a Muslim Bengali from Bangladesh. The age old Ghati-Bangal issue has always transcended religion to give primacy to geography instead.The cultural tradition of the subcontinent kept apart the Hindu migrants from East Bengal to India from the Hindu natives of West Bengal. Even some half a century after the partition of India, Calcutta newspapers continue to conspicuously mention the ancestral roots of prospective brides and grooms in matrimonial columns. One may attribute that to the discriminatory practices of the natives or to the exclusivist practices of the immigrants. But the fact remains that ancestral district can come in the way of tying matrimonial bonds between the Hindu natives and the Hindu immigrants in West Bengal. In fact, even among the Hindu immigrants themselves, a Baidya from Jessore or Bikrampur might find it beneath his dignity to have matrimonial ties with a Baidya from Sylhet or Comilla!

Many a nation state in the world exhibits regional variations in dialect and culture. The regional dialect and the local customs give the nation a “salad bowl” cultural milieu. Thus, Bavarians in Germany have the image of hillbillies. After the reunification of Germany, the people from the former East Germany were often perceived by their newfound compatriots as third worlders! Belgium and Switzerland have people speaking different dialects and even entirely different languages.

In USA, the Mecca of multi-culturalism, people speak of the East Coast, the Mid West or of the deep South with very specific cultural connotations. Let me narrate a personal anecdote. I took a speech course in an American college. During a discussion session, one student was frank enough to admit to her cultural bias based on regional accent. She told the class that Jamal has a non-American accent which is okay with her. But if she hears somebody with a southern accent, she seems to struggle with the thought that the person is of inferior intellect!Most religionists in Bangladesh take a victimological stance to justify their prejudices. They blame the arrogance of the Hindus from West Bengal or of the Hindu zamindar of yore from his own East Bengal for their antagonism toward all Hindus. But if they were honest enough, they would have readily admitted that there could be just as much a tradition of arrogance among the Muslims of Bangladesh. For many years, educated Bengali Muslims inhabiting the central part to the north western part of Bangladesh were extremely reluctant to enter into matrimonial ties with people from Noakhali, Chittagong and Sylhet. Similarly, many
Chittagongians and Sylhetees never could harbour the thought of marrying “foreigners.” I know of people from Noakhali who feel ashamed to disclose their roots. Many of them feigned to be from Comilla or Chittagong to get accepted by the Dhaka-centric “Bhadrolok” culture.

I was still a school kid when my father got transferred to Chittagong. It was a big cultural shock for me. I was afraid that I would never master the Chittagonian dialect, which is significantly different from the standard Bengali language. To my relief, I finally learnt to not only understand the local dialect but even speak in it after a fashion. A few years later, my father was transferred to Sylhet where I stoically withstood the scorn of my classmates who called me a “Bangal.” Needless to say, it was a pejorative. It was then that I learnt that the Sylhetees considered themselves to be from Assam. They were telling me that they did not think I was worthy of being a friend because I was nothing better than a “Bangal.”

I am sure I will have far less of a cultural shock if I visit Nadia in West Bengal. If I visit the Calcutta metropolis, I may cross path with some Bengalis (Hindus and Muslims alike) who may turn out to be somewhat different. But I doubt they will find me as different as I was found by my Chittagongian and Sylheti classmates. But then I have to bear in mind an
important aspect of social anthropology – many a person I will befriend in this old city have had the advantage of a college education and of urban living for many more than a generation or two. So, there is bound to be some difference between them and those I had encountered in Chittagong and Sylhet who were of rural background and may have belonged to the first generation in the quest of college education.

Jamal Hasan writes from Washington DC. The original article was published on March 19, 1999 in NEWS FROM BANGLADESH in its Commentary Section.

Advanced science, Bangladesh, Environmental, International, Life as it is, Political, Technical

We are hurtling towards a disastrous Climate Change (Part II)

In Part I, it was shown unambiguously that human activities from the period of industrial revolution (1720 – 1800) had been the root cause for the rise of global temperature by over 1ºC due to emission of greenhouse gases into the atmosphere. As industrial activities became more and more widespread, the greenhouse gas emission and its accumulation in atmosphere increased correspondingly and the global temperature went up even higher.

Climatologists, Geoscientists, Atmospheric Scientists and so forth had been warning the world leaders of signs of increase in global temperature over and above the natural increase right from the early 1970s. As time passed, their warning became louder and louder, but the leaders of industrialised countries deliberately ignored them or rejected their scientific evidence. United States of America is, in particular, the champion of such denial right from the beginning – presidents like Ronald Reagan, George H W Bush, George W Bush and recently Donald Trump are all rejectionists of man-made global climate change.

Despite incontrovertible scientific principle and evidence that increase in carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbon (CFC) and other gases in atmosphere traps energy i.e. heat within earth’s atmosphere and thereby increase global temperature, the deniers reject all these arguments. Their short-sightedness and the damage they are inflicting on Earth are simply inexcusable.

The consequences of global increase in temperature are given below:

When air temperature increases, land surface temperature increases more than the sea temperature, as heat capacity of water is more than that of soil. What it means is that for the same amount of heat, water temperature will increase less (due to its high heat absorbing capacity) than that of soil. Similarly, when air temperature drops, land temperature drop would be more than sea temperature. Thus, sea temperature does not move up or down as much as the adjoining land mass temperature and that is why we get the moderating effect of sea.

This land-sea temperature differential is also the cause of rain, storm, snowfall etc. In the summer, land temperature increases substantially causing air to rise to high altitude and sea air being relatively cooler and heavier but laden with moisture moves towards land and gives rain. A higher temperature difference would give higher amount of rain, higher wind velocity (storm, tornado etc). Reciprocally, in the winter there would be severe snowfall, extreme cold spell etc. So, the climate change would exacerbate the nascent conditions.   

Melting of inland glaciers around the world, which would then be followed by Antarctic and Greenland ice sheets melting would cause sea-level to rise significantly. It is not only the extra volume of water from melting ice but also the thermal expansion of water due to rise in temperature that would cause sea-levels to rise and inundate large areas of land mass. It is estimated by the Inter-governmental panel on Climate Change (IPCC) that by the end of this century, the sea-level is likely to rise by at least 6ft (or even higher), if no remedial action is taken now i.e. if life continues as ‘business-as-usual’. But if action is taken urgently now to limit temperature rise to 1.50C, the sea-level rise may be contained within 3ft to 6ft.

Figure 1. Mangrove areas of Sundarbans in Bangladesh at present

In addition to that, worsening storm surge, frequent tropical storm and concentrated rainfall will affect large coastal areas and even inlands of a country, islands and low-lying areas. Bangladesh, a low-lying country, would be badly affected by sea-level rise. The average landmass there is only about 5ft above the sea level. Figure 1 shows the mangrove areas of Sundarbans in the southern part of the country at present and Figure 2 when sea level rises by the smallest estimated margin of about 3ft.  It can be seen that large areas have been inundated by the rising sea level. It is estimated that 1.3 billion people world-wide would be affected, which may require their permanent relocation or even mass migration.

Figure 2. Mangrove areas of Sundarbans in Bangladesh anticipated to be around 2050 AD.

It may be pointed out that sea-level rise does not just cause submersion of landmass, which might have been habitable area previously, but also damages arable land. Ingress of saline water precludes cultivation of crops, vegetation etc even in surrounding areas which are not inundated. 

Thawing permafrost speed up global warming, as permafrost is basically soil that stays below freezing (00C) for at least two years. Plants capture carbon dioxide (CO2) from the atmosphere by photosynthesis process and then this carbon is released when wood (in roots) decays in the soil or carbon is compressed in the natural process to form coal. In Arctic areas, wood decay or decomposition is very slow and hence these areas are regarded as carbon sink. However, decomposition increases as temperature increases causing enhanced carbon emission. The inventory of frozen carbon in permafrost is 1.5 trillion tons, which is nearly twice the amount of carbon in the atmosphere now!

Wildfires are caused due to global warming and these then contribute to further global warming. Wildfire thus has a positive (destructive) feedback effect. Trees and vegetation absorb CO2 and convert it to oxygen (O2), thus acting as sinks. Tropical forests in Indonesia, Malaysia, Brazil and in other parts of the world play a vital role in carbon sequestration. However, wildfires effectively convert the sink of carbon straight into source of carbon! The forest fires that are razing in the Amazon rain forest now, which is regarded as the lungs of the planet Earth, are extremely damaging. These forest fires are not natural wildfires; these are deliberate man-made fires to clear forest areas for agricultural use (deforestation). Man is making the planet uninhabitable. 

The effect of all these changes is causing severe disruption to the climate. Where there were moderate rainfalls, now there are severe rainfalls causing flash flood, bursting of dams, landslides etc. In 2018, there were devastating floods in Japan, North Korea and India. In 2019, bridges in North Yorkshire, England collapsed when full month’s rain fell in just four hours.

While some parts of the world were having tremendous amount of rainfall in short spell of time, others were baking in heat waves. France’s capital Paris experienced this summer (June 2019) the highest temperature of 46ºC and India experienced 50ºC. Pakistan experienced a deadly heat wave where highest recorded temperature was 54ºC!

There were unprecedented wildfires in Greece and Australia. Wildfires in the forest area called Paradise in California are devastating and becoming a regular event. Northern Finland (in Arctic Circle) and Siberia were used to be considered so cold that wildfires were thought to be incredible, but not anymore. Last year as well as this year, wildfires in those areas devastated large land mass.

In the year 2017, hurricane Irna, a category 5 storm, was the most powerful Atlantic storm in a decade to strike the Caribbean and Southern US. In addition, hurricane Harvey in Texas and hurricane Maria in Dominican Republic wrought havoc. Monsoon floods in Bangladesh and mudslides in Sierra Leone are devastating natural disasters in 2017.

The frequency and severity of these natural disasters are breaking all previous records. A natural disaster, which only 10 or 15 years ago would have been considered once in 100 years event, is now happening once or twice a decade and if runaway conditions are allowed to continue, those events may become regular events!

Donald Trump not only denies man-made climate change but also encourages activities which cause climate change. He and his right-wing coterie of extremist Republicans in America hold and promote the view that climate change is due to natural phenomenon. There is an Institute in America, called the Heartland Institute (which Trump endorses and supports) which claims to be one of the world’s “leading free market think-tanks” and promotes “free market solutions to social, economic and environmental problems”. It disputes scientific observations and knowledge on climate change (as is usual with right-wing cliques to denigrate scientific knowledge), criticises climate mitigation activities and promotes use of fossil fuels. 

When confronted with increased severity and more frequent incidences of droughts, forest and bush fires, floods, storms, tropical cyclones, cold spells etc, these climate change deniers assert these are just natural phenomena; nothing to do with human activities. Their denial is either based on sheer ignorance or moral depravity.

Dr A Rahman is an author and a columnist


Bangladesh, Environmental, International, Life as it is, Political, Technical

We are hurtling towards a disastrous climate change (Part I)

The human race is staring at the disastrous climate change of their own making. The climate change clock is ticking remorselessly; it has gone past the 11th hour and, although not exactly on the 59th minute, but not too far from it. We pride ourselves to be civilised human beings, we claim unprecedented scientific and technical achievements; but we have failed to realise the damage we have inflicted and still are inflicting on our planet and our actions are anything but civilised. A large section of the human population under the guidance and influence of ‘civilised political leaders’ in many Western and Eastern countries is in complete denial of the climatic damage!

In order to appreciate how close are we to the tipping point of the irreversible climate change, we need to look at the factors that initiate climate change. The term ‘climate change’ embodies the totality of processes like global warming, sea levels rise, loss of polar ice caps, floods, fires, droughts and so forth. These processes do not take place for no reasons; there are deep rooted reasons for these effects.

The causes for these effects are multifarious. Causes range from emission of greenhouse gases from uncontrolled industrial activities, excessive exploitation of Earth’s resources, deforestation, rise in human population, demands for improved standards of living, increased air travel etc. All these factors contribute to climate change due to enhanced greenhouse gas emission. And the quantity that is primarily used to characterise climate change is the increase in global temperature.

The root cause of the increase in temperature is the increase in greenhouse gas concentration in Earth’s atmosphere. A sort of runaway situation has developed here. Increase in greenhouse gas leads to higher global temperature and higher global temperature leads to higher greenhouse gas. Unless decisive action is taken by human beings to arrest this situation, the human race is at peril. 

The legitimate question that arises here is that how can one assert this rise in global temperature leading to climate change is mainly due to human activities, when both natural processes and human activities do contribute to global temperature? That is a genuine question.  

The planet Earth had undergone over the millennia large climate swings. Scientists had looked into these variations in Earth’s climate over the past 650,000 years and found that there had been as many as seven ice ages during this period and in between ice ages there had been some warmer periods with increase in global temperatures. Modern human beings (Homo sapiens) had not yet evolved 650,000 years ago and so global temperatures could all be assigned to natural causes. There was no trend of temperature variation over this period.

When nearly 250,000 years ago, modern human beings emerged from the savannas in Africa, man started interacting with nature. But those primitive men had no way of exploiting the Earth; they were passive, subservient onlookers of nature.

Climatologists looked at the inter-glacial periods i.e. between two cold glacial spells and established a baseline temperature. After the baseline temperature was established, then any excess global temperature found over a period when human activity was known to have taken place can be assigned to human activities. This is an established scientific technique and it is applied to many scientific disciplines to separate out human activities from natural activities.

The planet Earth is blanketed by a layer of gases in the outer atmosphere. This atmosphere containing a variety of gases lets in solar radiation to come through, but blocks out or shields harmful ionising radiation from the outer skies. A small fraction of solar energy is reflected back from Earth’s surface to outer skies. Normally if the atmosphere is unpolluted, this reflected energy in the form of infrared radiation will escape to outer space. On the other hand, if there are pollutants such as carbon dioxide, methane etc, this radiation is held back and reflected towards Earth again. Thus, gradually excess energy is accumulated in the planet and its temperature goes up.

The types of gases that refuses to let infrared escape from Earth had been found to be carbon dioxide (CO2), methane gas (CH4), nitrous oxide (N2O), chlorofluorocarbon (CFC) and a few more. Atmospheric concentrations of carbon dioxide in ppm (parts per million) and methane gas in ppm over the period 1500 to the present time had been estimated by scientists and presented in the graphs below. The period 1720 to 1800 is the industrial revolution period when human activities kicked in large scale. Before this industrialisation period, humans were living in harmony with nature. It can be seen from both of these graphs that the industrial revolution was the spurt in increase in concentration which continued in accelerated fashion right up to the present day.

Greenhouse gas concentration from 1500 to 2000 AD
(Courtesy: http://www.theconversation.com)

Along with these two graphs, one should consider the rise in global temperature which is shown below. The similarity in the overall shape and pattern of these graphs is striking and one can draw conclusion that are correlated. It shows beyond doubt that the rise in temperature above the 1850 to 1900 (industrialisation period) baseline is due to increased concentration of global warming pollutants – CO2 and CH4. There are other significant pollutants such as chlorofluorocarbon (CFC), but it is not shown here.

The CO2 concentration in pre-industrialised period was between 200 to 270 ppm and Earth had a thermally stable period. But now this concentration has risen to about 350 ppm leading to about 1ºC rise in temperature. But, if the present trend continues, by the end of the coming decade the temperature may well go up more than 1.5ºC and that would bring in very harsh conditions for all forms of life on Earth.

Global average temperature and industrial baseline.
(Courtesy: http://www.theconversation.com)

From 1970s the scientists had been saying that human beings are damaging Earth’s atmosphere and its natural conditions and care should be taken to limit it or even reverse it. But political leaders of various persuasions, particularly Americans and vested interests dealing with fossil fuels, kept denying any global warming or any climate change etc. When confronted with increased severity and more frequent incidences of droughts, bush fires, floods, storms, tropical cyclones, cold spells etc, these climate deniers started saying that these are natural phenomena; nothing to do with human activities. Their denial is either based on ignorance or moral depravity.

Few countries holding such views are destroying the good work of large number of countries. Donald Trump, president of America, is the most famous deniers of all, mainly because America is the second largest polluter of the world and to limit polluting activities would cost America a lot. And hence denying the whole thing is the easy option. Pursuing such damaging policy, America, under Donald Trump, had withdrawn from the Paris Agreement in 2017.

The Paris Agreement of 2015 aims to limit global warming to 1.5ºC relative to a pre-industrial baseline. Its precise commitment is:

Holding the increase in the global average temperature to well below 2℃ above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5℃ above pre-industrial levels, recognising that this would significantly reduce the risks and impacts of climate change.

We all live in the same planet. If one country i.e. America, the second largest polluter, keeps damaging the planet for its own benefit, that would wipe out the sacrifices of large number of countries. America is pushing the Earth to a precipice for their selfish interests.

(The next Part (Part II) will deal with the likely consequences of the present predicament and the most likely prediction of the future scenario.)


  • Dr A Rahman is an author and a columnist
Bangladesh, Economic, Environmental, International, Life as it is, Technical

Our oceans: The ultimate sump

Plastic pollution

Today is “World Oceans Day,” a day observed worldwide to raise awareness about the crucial role the oceans play in sustaining life on Earth. It is also a day to appreciate the beauty of the oceans that “brings eternal joy to the soul.”

The oceans are among our biggest resources and also our biggest dumping grounds. Because they are so vast and deep, many of us believe that no matter how much garbage we dump into them, the effects would be negligible. Proponents of dumping even have a mantra: “The solution to pollution is dilution.” Really! In case they don’t know, garbage dumped into the oceans is continuously mixed by wind and waves and widely dispersed over huge surface areas.

There is a zone in the Pacific Ocean, called The Great Pacific Garbage Patch, which is a gyre of marine garbage twice the size of Texas. The garbage, mainly microplastics, were carried there by strong currents from other parts of the ocean. This is not the only floating garbage in our oceans. The Atlantic and Indian Oceans have their own garbage patches. Worse yet, the sheer size of the patches is making clean-up efforts an extremely difficult task.

Surely, human activities are impacting the oceans in drastic ways. Some of the anthropogenic environmental issues that are affecting the oceans are plastic pollution, oil spills, climate change and noise. One of the most dangerous threats the oceans may face in this century is radioactive pollution.

Each year, we dump nearly eight million tonnes of plastic—mostly grocery bags, water bottles, yogurt cups, drinking straws and plastic utensils—into the oceans. Recently, plastic has been discovered in the deepest part (11 kilometres) of the world’s oceans, Mariana Trench in the Pacific Ocean. Extremely elevated concentration of PCBs, an environment-damaging chemical banned in the 1970s, have also been found within the sediment of the trench.

While it takes hundreds of years for plastics to decompose fully, some of them break down much quicker into tiny, easy-to-swallow particles that can easily be ingested by marine species causing choking, starvation and other impairments.

Pollution of the oceans by oil spills has been one of the major concerns for a long time. The primary source of spill is offshore drilling. The process is inherently dangerous and thus, is prone to accidents. When accidents happen, and they do happen without warning, they cause massive damage to the environment—aquatic and shore—that persists for decades to come. Some oil spills happen when tankers transporting petroleum products have accidents.

If the layer of the oil is thick enough, it smothers creatures unable to move out from under it. Besides, swimming and diving birds become covered with oil, which mats their feathers, reducing their buoyancy and preventing flight. The insulative value of feathers is also lost and the birds quickly die of exposure in cold water.

The world’s largest oil spill was not an accident; it was the result of the Persian Gulf War in 1991. The second worst disaster was the spill by BP’s Deepwater Horizon offshore rig in the Gulf of Mexico in April 2010. Both incidents killed tens of thousands of birds, marine mammals, sea turtles and fish, among others.

Land and oceans together absorb slightly more than half of all the carbon dioxide emissions, with the oceans taking a greater share. When carbon dioxide dissolves in water, it forms carbonic acid. Various studies estimate that if we keep on pumping carbon dioxide into the atmosphere at the current rate, then by the year 2100, the water of the oceans could be nearly 150 percent more acidic than they are now. Such a large increase in acidity would upset the productivity and composition of many coastal ecosystems by affecting the key species at the base of the oceanic food webs. It would also reduce calcium carbonate, which is essential for building the shells and skeletons of creatures like mussels, clams, corals and oysters.

Because oceans absorb more than 90 percent of the heat that is added to the climate system, sea level is changing, albeit unevenly. It is changing unevenly as oceans do not warm uniformly across the planet, with the southern oceans warming at a faster rate. In addition, global reef systems are slowly migrating poleward as oceans around the world continue to warm.

The single most significant contribution to rising sea level is from the thermal expansion of water. Melting ice makes the second most important contribution, but only melting of land-based ice—glaciers, ice caps and ice sheets—is significant. Ice that is already floating in the water—iceberg—makes essentially no change in sea level when it melts, because the greater density of water offsets the volume of ice that is not submerged. Other factors that contribute to the rise in sea level include wind and ocean circulations, depth of the oceans, deposition of sediments by river flows and alteration of the hydrologic cycle by humans.

According to some studies, global sea level rose by about 18 cms during the last century. In the worst-case scenario, sea level could rise by two metres by the end of the year 2100. Arguably, rising sea level is among the potentially most catastrophic effects of human-caused climate change.

The oceans are no longer “The Silent World” of the famous oceanic explorer Jacques Cousteau. Today, they are being acoustically bleached by noise from seismic blasts used for offshore oil and gas exploration, marine traffic and military sonar.

Unlike plastic pollution, noise pollution does not have the visual impact that is needed to spark an outcry and force action. It is an invisible menace that is drowning out the sounds of many marine animals, including fish, use for navigation, communicating with each other, finding food, choosing mates and warning others of potential dangers.

Whales and dolphins are particularly vulnerable to noise pollution. The deafening seismic blasts and the ping of sonar are responsible for the loss of their hearing and habitat, and disruption in their mating and other vital behaviours. The disappearance of beaked whales in the Bahamas in recent years have been attributed to testing of US Navy sonar systems in the region.

From 1946 through 1993, nuclear countries used the oceans to dispose of radioactive wastes. The United States alone dumped more than 110,000 containers of nuclear material off its coasts. Russia dumped some 17,000 containers of radioactive wastes and several nuclear reactors, including some containing spent nuclear fuel.

It is highly likely that radioactive wastes would eventually leak out of the containers because of poor insulation, volcanic activity, tectonic plate movement and several other geological factors. Indeed, last month, UN Secretary General Antonio Guterres confirmed that a Cold War era concrete “coffin” filled with nuclear waste is leaking radioactive material into the Pacific Ocean. Since radiation from nuclear wastes remains active for hundreds of thousands of years, their dangerous effects will linger for a long time and will have lethal impact on marine life.

Furthermore, six nuclear submarines — 4 Russian and 2 American — lost as a result of accidents are lying at the bottom of the oceans. They represent serious threat of radioactive contamination of the oceans, too.

One of the biggest contaminations due to radiation was caused by a series of nuclear tests conducted by the USA on the sea, in the air and underwater at Bikini Atoll in the North Pacific between 1946 and 1958. The French nuclear tests carried out during 1966-1996 in French Polynesia are responsible for other cases of intense radioactive pollution of marine ecosystems.

Clearly, we are using the oceans as the ultimate sump, partly because their very immensity seems to preclude any long-term effect, and partly because they belong to no one. This cannot continue indefinitely because in order for us to survive, we have to protect the oceans. Lest we forget, life emerged from the oceans and the source of most of the oxygen we breathe are the oceans. They have been an endless source of inspiration to humankind.

Quamrul Haider is a Professor of Physics at Fordham University, New York.

Advanced science, Bangladesh, Environmental, International, Life as it is, Technical

Cyclone Fani and global climate change

The temperature of the Earth changes over geologic time. During periods of glaciation, it was about five degrees Celsius cooler and in the interglacial period about five degrees warmer. The last glaciation period was 100,000 years ago. Since then, there have been fluctuations of a few degrees, the period of 1430 to 1850 being one of particularly low temperatures in Europe. Although there were fluctuations from year to year, it seems evident that there has been a steady increase in average global temperature since the Industrial Revolution. According to the World Meteorological Organization, average global temperatures will reach a new milestone this year—one whole degree higher than temperatures before industrialisation.

In the early 1990s, when concern about climate change caused by the rise in temperature became widespread, the “signal” of anthropogenic effects hadn’t unambiguously emerged from the “noise” of natural climate variability. However, we now know that most of the climate-related changes observed over the past 50 years is attributable to human activities. In fact, by burning prodigious amounts of fossil fuels that emit carbon dioxide, which is the principal greenhouse gas, we humans have taken Earth’s atmosphere in general and global temperature in particular into a regime that our planet hasn’t seen for millions of years.

Although the interplay between carbon dioxide and temperatures is complex and not necessarily 100 percent predictive, nevertheless, the obvious correlation between the two variables suggests that we might expect a significant adverse climatic response to the industrial-era surge in fossil fuel derived atmospheric carbon dioxide. Undeniably, the effects of this interplay are manifested in the increase in the ferocity of storms, floods of biblical proportions, spike in the number of unusually hot days, melting of the glaciers, drought, desertification and deforestation, polar vortex, uncontrollable forest fires, degradation of the coral reefs, habitat loss and rise in the sea level, to mention a few.

Today, because of global warming, intense storms are occurring in many parts of the world. If they form in the Atlantic or Caribbean, they are known as hurricanes, and in the Pacific or China Sea as typhoons. If they develop off the coast of Indian Ocean or the Bay of Bengal, we call them cyclones. These storms are one of the most awe-inspiring displays of the raw power of nature. They are also among the deadliest and costliest natural disasters we have to contend with routinely.

After churning through the Bay of Bengal for several days, gathering immense amount of energy along the way, cyclone Fani roared through Bangladesh on May 4, 2019, leaving behind a massive trail of destruction—killing more than a dozen people, knocking out power, shredding roofs and leaving hundreds of thousands homeless. Classified by meteorologists as the equivalent of a Category 4 hurricane, it was one of the most intense cyclones in 20 years in the region.

Cyclones batter Bangladesh at regular intervals, mainly in April/May or October/November, when weather conditions align in a manner most favourable for storm origination and sustenance. As examples, cyclones Aila struck southern Bangladesh on May 27, 2009 and Sidr made landfall on November 14, 2007. The occurrence of these and other cyclones in close succession is a reminder of the country’s extreme vulnerability to the devastating effects of human-induced climate change.

The 1970 cyclone that hit Bangladesh on November 12 and raged the strongest on November 13 was the worst natural disaster we have witnessed so far. The resulting storm surge, more than 20 feet high and topped by huge tidal waves, washed over offshore islands and carried water from the sea many miles inland. The cyclone and flood destroyed the entire infrastructure of the country’s southern coast and killed an estimated half a million people, though some researchers estimate that the death count was close to a million. The failure of the Pakistani government to respond quickly to the crisis, among other things, contributed to the political turmoil that led to an independent Bangladesh in 1971.

Tropical cyclones are influenced by many factors, but the role of warm sea-surface temperatures is the primary source of energy for cyclones. In particular, a cyclone gets most of its energy from the latent heat of condensation and the moisture generated from the sea. Thus, for the genesis of cyclones, temperature of water near the surface of the sea must be higher than 27 degrees to a depth of at least 150 feet. Additionally, heat from the sea and Earth’s counter-clockwise rotation conspire to create the cyclone’s spin and propulsion. Furthermore, rising sea levels mean that surges produced by cyclones are much more powerful, thereby increasing the risk of inland flooding.

Moreover, cyclones need to be at least 300 miles from the equator, where a deflective force known as Coriolis force resulting from Earth’s rotation begins to take effect. When cyclones reach land, or cooler water, they lose energy as the conditions necessary to reinforce them are no longer present.

As a result of global warming, temperature near the surface of the Bay of Bengal varies from 27 degrees in January to more than 31 degrees in May. The unusually warm water, together with geographical and environmental factors, make the Bay of Bengal a hot spot for cyclonic activity.

Can changes in frequency and intensity of cyclones observed so far be attributed solely to anthropogenic global warming as against long-term periodic natural variations? Cyclones are affected by natural fluctuations too, driven by external factors, such as solar variability and volcanic eruptions, natural internal variations of the complex physical, chemical, and biological systems of Earth.

Additionally, research has shown that urbanisation significantly contributes to the amount of rainfall dumped, as evidenced by over 130 centimetres of rain that fell on the Houston region during hurricane Harvey in 2017. This is because the “roughness” of the city—as in the buildings and infrastructure—creates a drag on the storm system, causing it to slow down, resulting in more rain over the city area.

Climate models predict that global warming could spawn more bizarre and violent weather, notably cyclones and severe floods in the future. Indeed, while people are trying to come to grips with the effects of Fani, meteorologists have warned that Bangladesh is likely going to experience another cyclonic storm called Vayu some time later this month.

The models also predict that by the end of this century, global warming effects could increase a cyclone’s intensity by about 20 percent, making them more destructive than ever. The amount of rainfall would also increase substantially. Other estimates predict that a doubling of carbon dioxide concentration would result in a 40-50 percent increase in destructive cyclones.

So, what should we do to keep our planet in the so-called Goldilocks zone of the solar system? We have to make a concerted effort to end our dependence on fossil fuels. We have to replace them with non-polluting, renewable sources of energy. We have to develop more carbon-free energy technologies. We have to sequester carbon dioxide emissions using the available technology. More importantly, we have to shun the “business as usual” attitude. In short, we will have to build a sustainable future. Otherwise, climate change will cause our civilisation to collapse.

Quamrul Haider is a Professor of Physics at Fordham University, New York.