Advanced science, Astrophysics, Cultural, International, Life as it is, Religious, Technical

Dark Matter and Dark Energy – Part II

In the 1st part on this topic the essential attributes of dark matter had been described. Dark matter was necessary in order to hold the basic fabric of galaxies together; otherwise, billions of stars at the edges of the galaxies would experience weaker gravitational pull and could even fall away from the galactic orbits. So, dark matters were invoked to be present all over the galactic system.  In this part, the role of the dark energy will be considered. Dark matter may keep the individual galactic system intact and maintain higher orbital speeds to outlying stars, but then what is giving the Universe impetus to expand?   

The ‘Standard Model’ of the cosmological system predicted that the Universe simply could not exist in a quiescent steady state – it has to be dynamic in nature, meaning it either has to expand or contract. Indeed, in 1929 Edwin Hubble made an astronomical observation and that had become incontrovertible showing that the Universe was actually expanding. That made Einstein to admit that his cosmological constant, Ʌ (lambda) introduced in the general theory of relativity with a particular value to force a steady state condition for the Universe was flawed. For the next 70 years, until 1998, cosmologists implicitly took Ʌ to be zero and the Universe was described as per Einstein’s field equations. Nobody thought of discarding the cosmological constant that Einstein had introduced, albeit mistakenly.

Then in 1998, another even more astounding evidence was produced based on observation using Hubble telescope, when it was shown that light from very distant supernovae was fading away and showing red shifts indicating supernovae were receding and receding at faster rates further they were from the Earth. In other words, there was an accelerated expansion in the Universe. The Universe’s current expansion rate is known as the Hubble constant, H0 which is estimated to be approximately 73.5 km per second per megaparsec. A megaparsec is the distance of 3.26 million light years. As the speed of light is 3×108 m/s or 9.46×1012 km/year, 1 megaparsec then equals to 3.08×1019 km. A galaxy 1 megaparsec away (3.08×1019 km) would recede from Earth at 73.5 km/s; whereas another galaxy 10 times of 1 megaparsec from the Earth would recede at 10 times of 73.5km per sec = 735 km per sec.  That was a shocking result and the cosmologists were taken completely by surprise.  

What is providing this gigantic Universe enough energy to expand and expand at an accelerated rate? Further observations had demonstrated that this accelerated expansion is in fact taking place in the vast extra-galactic spaces. This came to be known as the ‘metric expansion’. There was no evidence or verifiable evidence of expansion within the individual territories of galaxies. It may indeed be argued that if there were any expansion within a galactic system, then stars would move away from each other and even the planets revolving round the stars would recede. For example, Earth would recede from the Sun and that recessive path would look like a spiral trajectory and eventually Earth would secede completely from the Heliosphere! This would be a recipe for a total disaster for the Earth-bound lives like ours and luckily there was no such evidence of recession. 

Expansion of the Universe as per Standard Model

Albert Einstein’s cosmological constant, Ʌ in the general theory of relativity came to the rescue of this paradox of cosmological expansion. Dark energy was invoked to solve this problem. Dark energy is perceived to be the intrinsic energy of the empty space or simply the vacuum energy. It may be pointed out that space is viewed in the general theory of relativity as the product of gravitational field. As there are limitless empty spaces in the cosmological scale, dark energy can also be limitless. Although the precise mechanism of generation of dark energy is unknown, but some of the essential characteristics may be drawn. Dark energy is repulsive in character. Thus, dark energy can be viewed as something that reacts with ordinary matter (baryonic matter) making up the celestial bodies, but in opposite direction to ordinary gravity. Some scientists speculate that dark energy may even be a form of a new type of force – the fifth force – which is as yet unknown. The known four forces are: electromagnetic force, weak nuclear force, strong nuclear force and the gravitational force and the properties of these forces are well known. If indeed the fifth force does come into play, it would offer a situation where gravity and anti-gravity may come to exist in the same Universe. It may be that the attractive gravity exists within the scale of galaxies, whereas repulsive gravity exists in the vast extra-galactic space!  

Taking material accounting of galaxies into consideration, it is estimated that on the basis of mass-energy composition, the Universe is only 4.5% of ordinary matter, 26.1% of dark matter and 69.4% of dark energy. However, this distribution of mass-energy composition in observable celestial bodies and unobservable black holes do not remain fixed or invariant. At the early part of the Universe’s formation, after about 380,000 years following the Big Bang (13.8 billion years ago), the distribution mass and energy was quite different. Ordinary matter was 12% and dark matter was 63% and there was no dark energy, as shown in the Table below. The situation is quite different now and this shows that the Universe is changing or one can say evolving.

Universe’s mass-energy composition

 13.8 billion years agoPresent day (2000 CE)
Dark energy69.4%
Photons15%
Ordinary matter12%4.5%
Neutrinos10%
Dark matter63.0%26.1%

In the Universe, the amount of ordinary matter (baryonic matter) is fixed and as the Universe expands, the average density of ordinary matter in the Universe is continuously diminishing; as density is the amount of material divided by the volume. Similarly, the dark matter density of the Universe is also decreasing as Universe expands. But the dark energy density had been found to remain constant, no matter how much or how fast the Universe expands. It is due to fact that vacuum energy is constantly added (as space has intrinsic vacuum energy) to the pool of dark energy as Universe expands and hence the dark energy density remains constant.

In the metric expansion, the space or more appropriately, spacetime fabric is created extra-galactic. Space is not something which is devoid of other things. Space is the gravitational field. Like electromagnetic field, gravitational field generating space is granular in character. The quantum of space is so incredibly small that we cannot sense them, similar to solid granular atoms we cannot feel. Space granules are literally trillions of times smaller than atoms. Space granules or space quanta are not within the space, space quanta are the space. A new branch of physics, called ‘loop quantum gravity’ shows how space quanta make up the space. When Universe expands, space is produced with spacetime quanta and the intrinsic dark energies increase.

Although the evidence of accelerated expansion of the Universe was baffling, but it was not unexpected. The Universe had undergone very rapid expansion at the early phase of its existence, some 13.8 billion years ago, after that it slowed down for billions of years and then the expansion phase started about four or five billion years ago. When this expansion will stop or even reverse, nobody knows. But it is definite that the Universe as a whole is not static, it is very much dynamic, vibrant and evolving. If anybody says that the Earth, Sun and Moon and even the whole Universe were created by some unknown Creator and then he left the whole thing in a quiescent state, then there is every reason to question such unfounded claims and discard them as totally baseless.  

  • Dr A Rahman MSRP CRadP FNucI
Advanced science, Bangladesh, Cultural, International, Life as it is, Literary, Technical

Tagore’s philosophical views and Quantum Mechanics

Rabindranath Tagore (actual Bengali name: Rabindranath Thakur) (1861–1941), the great Indian philosopher, a Bengali poet and a polymath, who received Nobel Prize for Literature in 1913, lived during a transition period of Indian history in general and the Bengali culture in particular, when physics also went through revolutionary changes. Albert Einstein (1879–1955), the most prominent physicist of the 20th century, was the pioneer of modern physics, who produced theories which advanced physics to unprecedented levels. Although Einstein produced the ‘the principle of photoelectric effect’ for which he received the Nobel Prize for physics in 1921 and which was pivotal to the advent of quantum mechanics, he could not fully reconcile with the multifarious implications of quantum mechanics. The two stalwarts of the first half of the 20th century met a number of times from 1926 onwards. When Tagore visited continental Europe and then America in 1930, they met at least four times in Berlin and New York. The meeting at Einstein’s summer villa outside Berlin was of particular interest when they exchanged views and philosophical ideas extensively. During that meeting – poignantly described by Dmitri Marianoff, a journalist in the New York Times, as being between ‘Tagore, the poet with the head of a thinker, and Einstein, the thinker with the head of a poet’ – the two exchanged views on the reality of nature.

Einstein held the view that the world and, for that matter, the whole universe, is there independent of humanity. Tagore held the view that the world is a human world and hence without humanity, the world is irrelevant and non-existent. Einstein persisted and queried that aren’t beauty and truth absolute and independent of man? Tagore disagreed and said that truth is realised through man and without man it does not exist. The whole conversation between these two giants was absolutely fascinating – it brought out the mindset of a scientist seeking out nature as it exists and that of a poet observing nature through the eyes and minds of human beings.

Einstein’s commitment to the reality of nature was absolute, and that absolutism brought him into conflict with the quantum reality proposed by Niels Bohr, Werner Heisenberg and others. Einstein believed in the existence of causal, observer-independent reality; whereas quantum mechanics considers reality dependent on the act of observation. Bohr/Heisenberg proposed that an atomic particle like an electron is there only when it is observed. If it is not observed, it is not there; it could be anywhere only to be described by quantum functional description. But Einstein would not accept that. He retorted by saying that the moon is there in the sky whether you observe it or not. Quantum mechanics states that an entity having unobserved presence cannot be claimed to be present with absolute certainty (with the probability of 1). Quantum mechanics tell us that the observer and the observed are entwined. The reality is not pre-ordained; reality is what is observed.

In 1928, Tagore received Arnold Sommerfeld, professor of theoretical physics at the university of Munich and a pioneer of atomic spectra, at Shantiniketan, West Bengal. Sommerfeld stated, “Tagore is to India what Goethe (pronounced as Görta) is to Germany”. Sommerfeld’s student Werner Heisenberg visited India the following year.

Heisenberg was one of the principal architects of quantum mechanics and his ‘uncertainty principle’ is the cornerstone of quantum mechanics. During the 1920s, he, along with Niels Bohr and others, produced what is now known as the ‘Copenhagen Interpretation of quantum mechanics’, where multiple existence of an atomic particle at different locations with superposition of quantum states was considered to be the reality of nature.

Although quantum mechanics had enormous success and explained various physical phenomena, which classical physics was incapable of explaining, the conflict with Einstein on quantum mechanical fundamental assumptions of probabilistic description was deep rooted. Einstein considered quantum mechanics as an incomplete description of nature.

In 1929, when Heisenberg undertook a lecture tour around the world, he came to India. On 4 October 1929, he visited the University of Calcutta and in the afternoon, he visited Tagore. In fact, he was taken to Tagore’s house at Jorasanko by the scientist Debendra Mohan Bose, a nephew of Jagadish Chandra Bose, and they had a number of conversations over the next few days. Heisenberg was very much impressed by Tagore’s philosophical views. Fritjof Capra in his book Uncommon Wisdom wrote,:

“In 1929 Heisenberg spent some time in India as the guest of the celebrated Indian poet Rabindranath Tagore, with whom he had long conversations about science and Indian philosophy. The introduction to Indian thought brought Heisenberg great comfort. He began to see that the recognition of relativity, interconnectedness and impermanence as fundamental aspects of physical reality, which had been so difficult for himself and his fellow physicists, was the very basis of the Indian spiritual traditions.”

Heisenberg said, “After these conversations, some of the ideas that had seemed so crazy suddenly made much more sense. That was great help for me.”

Heisenberg’s comfort was to be seen in the context of a great intellectual battle that had been raging at that time between Einstein and Bohr/Heisenberg on the reality of nature. Indian mysticism or more accurately, Tagore’s interpretation of Oriental (Brahma) philosophy, giving a support to modern physics and quantum theory, was undoubtedly a great comfort to Heisenberg. No wonder, Heisenberg even said after their conversations that Tagore reminded him of a prophet of the old days!

Tagore’s philosophy of viewing the world with human eyes may seem to conflict with Einstein’s observer-independent reality, but these are two perspectives of the reality. Tagore’s view of reality resonates very well with the quantum philosophy of observer-dependent reality.

Dr A Rahman is an author and a columnist

Bangladesh, Disasters - natural and man-made, Economic, Environmental, International, Life as it is, Political, Technical

Can we create an environmentally habitable Bangladesh?

Since independence, Dhaka’s population had exploded from just about 1.5 million in 1971 to over 21 million in 2020, a 14-fold increase as opposed to 2.5-fold for the entire population of Bangladesh. Hence, for all practical purpose, Dhaka is Bangladesh. As a consequence, Dhaka has undergone rapid unplanned urbanisation that has replaced its natural environment with a new environment. It is now a boom town with a thriving real-estate market, a growing middle class, and a vibrant gastronomic, cultural and intellectual life. In a nutshell, Dhaka is an incredibly bubbly city, full of energy and pizzazz.

Having said that, amongst the least liveable cities in the world, Dhaka is ranked behind Lagos in Nigeria, and the capitals of war-ravaged Libya and Syria. And in the Human Development Index, Bangladesh stands at 133 out of 189 countries. These statistics, though unflattering, reflect the myriad of problems with which Dhaka and other cities in Bangladesh are beset with, thereupon making them surreal places to live, places that are both frenetic and paralysed.

Unbridled expansion of cities in Bangladesh has often meant inept replacement of houses in residential areas of yesteryears with multi-storied luxury apartments, high-rise offices, ritzy shopping malls, cultural centres, sports facilities, private schools and universities. In the process, low-income families have been forced into slum-like neighbourhoods, while the poorest of the poor have been pushed into omnipresent slums, where communicable diseases fester and fires sporadically raze homes to the ground.

Stifling in the summer, often overrun with cockroaches, rats, stray cats and dogs, with trash littered all over the neighbourhood and obnoxious odour emanating from the sewer-less, burlap draped, precariously perched outhouses, a slum is unquestionably a rotten place to stay. In their zeal to gentrify cities so that they become liveable for the upper- and middle-class people, city fathers often throw out the proverbial baby with the bathwater. Instead, with a more humane approach, slums can be improved to the point where they become safer and environmentally cleaner places to live. As an example, Harlem in Upper Manhattan in New York City once epitomised poverty, crime and crumbling infrastructure. In the 1980s, urban renewal projects that included community revitalisation and housing rehabilitation programmes radically transformed the ghettos of Harlem into endurable hamlets.

In the race to accommodate ever-increasing numbers of people, cities and suburbs are likely to continue to sprawl across Bangladesh. The sprawl, however, need not be chaotic. In the new cities and suburbs, there should be preservation of some open space through parkland, promenades, scenic easements and cluster zoning that will provide breathing space and a sense of relationship between man-made environment and natural environment. Schools, houses of worship and neighbourhood parks, to name a few, should be within walking distance of the residential areas. This will reduce dependence on cars that are a major cause of global warming, not counting traffic jams. Simply stated, before any amelioration of the grimmer aspects of urban life can be hoped for, long-range green planning is imperative. Otherwise, we will be living in an eco-unfriendly jungle of concrete structures.

As cities grow in size, so does their impact on the environment. Most importantly, they can modify some of the local climatological factors in their immediate vicinity, resulting in a relatively small-scale but tangible variation in the local climate, which is called “urban heat island effect,” or more generally microclimate.

On a hot summer night, when we walk down a city street, we can feel the heat shimmering up from the dark asphalt roads and concrete pavements which absorb copious amount of solar radiation, whereas in wintertime, we can see clouds of steam pouring out of manholes or sewer gratings. With the loss of evaporative cooling normally provided by vegetation and exposed soil, the gain of reradiated heat from these surfaces, sewers and buildings, along with the heat produced by industries, the mean temperature of cities is on the rise. While microclimate does not produce dramatic changes in temperature, over the years the cumulative effects of these heat sources are clearly noticeable in the average temperatures of 1970s Dhaka and present Dhaka.

For the improvement of urban microclimate, it is important to maintain and/or create cold-air areas, open spaces and wooded patches. Trees an effective tool at fighting global warming will help to reduce temperature of the air by a process known as transpiration cooling. Furthermore, connected parks and green zones, preservation of lakes and rivers, creation of artificial water surfaces and large-scale heat retention expanses are essential elements of a habitable city.

Apart from microclimate, buildings contribute substantially to global warming because they use lots of energy usually generated by fossil fuels for cooking, lighting, heating and cooling. The reduction of heat loss in the winter and cool air in the summer through poorly insulated old windows is the key to mitigating the impacts of climate change. Additionally, within the context of local environmental and socioeconomic factors, several studies have been conducted to find innovative green solutions to the many climate-related problems caused by buildings. One of them is white roof which, according to researchers at the Lawrence Livermore National Laboratory in California, reflects three times the sunshine than a green rooftop garden that is used in many residential buildings in Dhaka.

In terms of air quality, Dhaka ranks as one of the worst cities in the world. Because the city is perennially drowned in a sea of polluted air, it is often labelled as “hell with the lid off.” Indeed, the entire population of Bangladesh is regularly exposed to unhealthy levels of pollutants in the air.

Most of the pollutants in Dhaka’s air and elsewhere are anthropogenic, such as effluents from vehicles, emissions from industries and power plants using fossil fuels. Other sources are roadside waste dump facilities, methane-emitting agricultural waste, contaminants from foundries, not to mention dust and smoke from the thousands of slender, cylindrical chimneys attached to the wood- and coal-fired kilns of brick fields. The large quantities of pernicious pollutants emitted by these sources are precursors to the formation of smog, the worst form of air pollution with dangerous health consequences, especially for children and the elderly.

While Millennium Development Goals have helped many countries combat the issue of unsafe drinking water, majority of Bangladeshis still do not have access to clean water. Tap water supplied by local municipalities is dirty and therefore undrinkable, while people in the countryside are drinking water contaminated with arsenic and other life-threatening heavy metals.

A possible solution to the freshwater problem is rain and the roof a la Bermuda. Made of limestone blocks and sliced into individual slates, the roofs of houses in Bermuda are fashioned in step-like sloped surfaces with gutter ridges to collect rainwater, the most precious liquid in the tiny island nation. The ridges direct the water through a long concrete trough to a pipe that filters and funnels it into a tank buried alongside the house so that it can be pumped and used throughout the household.

All the cities in Bangladesh are dirty beyond description. Garbage can be found everywhere—by roads, on the roads; around parks, in the parks; by rivers, in the rivers; inside trash cans, outside trash cans. Garbage disposal is not a recent problem, though it certainly has been made more difficult by the sharp rise in population in the past few decades. Despite some progress, the overwhelming mass of household garbage is thrown into landfills in the outlying areas of the cities and left untreated. These unsightly and smelly midden heaps not only emit poisonous gases that are harmful to human health, but also provide a cosy home for the disease carrying vermin, mosquitoes and flies.

The problem is exacerbated during the monsoon season, when cities become submerged for days in a row. Consequently, the storm drains, albeit few and far between, clog up and the cities resemble a huge pond filled with filth and scum.

Finding a clean public toilet anywhere in Bangladesh is next to impossible. Decency dictates that women must suffer, yet allows men to indulge in the malpractice of emptying their bladder by the roadside. The offensive smell of urine, together with malodorous roadside trash, not only makes walking on the sidewalks a horrific experience, it also contributes markedly to odour pollution which, in turn, worsens the already poor quality of air.

As much as the government is battling to tackle this civic problem with signs at strategic points warning of prosecution for infractions, the seemingly endless number of offenders ignore the warning and happily continue to relieve themselves in public. That being so, we have no choice but shame the perpetrators.

Humans are not the only waste producers in Bangladesh. Industries are not far behind. Of the many industries which add hazardous wastes to the load already present from domestic wastes, two stands out conspicuously. They are garment factories and tanneries.

The canals and wetlands of Savar and Ashulia, located near Dhaka and home to hundreds of garment factories, are now effectively retention ponds of untreated waste and effluents produced by these factories. Nearby rivers are so polluted with toxic materials that they run purple, blue and black. Aside from making agricultural land barren and useless, the pollutants are loading the local air with noxious fumes.

Hazaribagh in the heart of Dhaka was once home to a slew of tanneries. Before their relocation to Savar, the tanneries discharged unprocessed liquid waste containing deadly chemicals into the nearby ponds, rivers and canals. These wastes eventually ended up in the Buriganga River whose once pristine blue water now looks like turbid sewage water. Needless to say, the river has suffered irreversible biodiversity loss.

Another plague from which there is virtually no escape, irrespective of where we are—in our homes and gardens, on our streets, inside our cars, parks and in other public places, is noise. Like second-hand smoke, noise has become an unwanted pollutant produced by others and imposed on us without our consent, often against our will. Without question, noise can damage hearing and there is no threshold for ear damage. But more subtly, noise increases tensions already heightened by other stresses of urban life.

Among the many sources of outdoor noise pollution, cacophony produced by the horns of automobiles, trucks and buses are the worst offenders, followed closely by construction equipment. The sound intensity level from these sources often exceeds 120 decibels, which is the threshold of pain.

Noise is a controllable pollution, but sadly the government has done very little to alleviate the suffering of its citizens from this scourge. Nevertheless, there is something we can do to stop noise from invading the interior of our house. Within the buildings, we can dampen sound significantly by constructing walls with dead air spaces.

Forests are the lungs of a nation, purifying the air we breathe. However, the increasing demand for land for agriculture, homes and industries caused by population explosion is taking a heavy toll on the forests in Bangladesh. To meet the demands, close to half the forests have been destroyed in the last 20 years or so by indiscriminately cutting down trees. Moreover, once the coal-fired Rampal Power Plant goes into operation, one of the most ecologically sensitive rainforests in the world – the Sundarbans – will be in its firing line.

Lest we forget, nature not only abhors vacuum, it abhors human interference, too. A true wilderness should be viewed bio-centrically. The forests should be free to burn, free to be blown away by storms, free to be washed away by floods and free to be attacked by insects. These are natural events to which forests are adapted to respond. The new forests that will emerge may be different from the old ones, but that is the way things change in a natural ecosystem.

The present problems of Bangladesh, alarming no doubt, are not unsolvable. There is every reason to expect that the country can be made habitable. To that end, policymakers need to know how transportation system can be designed to meet the needs of the people; what makes one neighbourhood exciting to live in and another boring; what human needs are not met in present housing; what environmental steps should be taken to improve the quality of air and water, and so on and so forth? The answers to these questions can then be incorporated in any future plans for redesigning old cities or building new ones, so that they not only become liveable but enjoyable as well.

At the same time, Bangladesh’s transformation into a liveable country cannot be achieved overnight. It will perhaps take decades, but before that climate change will leave an indelible mark on the country, thereby making the task of restoring liveability conditions even more arduous, mainly in the low-lying coastal areas.

Bangladesh is Mother Nature’s punching bag. The country is experiencing extreme weather phenomena that are growing only more dramatic, more devastating and more lethal by the year. Of the many threats from climate change, sea level rise will certainly be amongst the most impactful, making the entire coastline of Bangladesh uninhabitable and potentially displacing tens of millions of people in the coming years.

Preparing for climate change is much more than a technological challenge. It is primarily a problem of mindset and collective action. The way to outsmart breakdown due to climate change is to build climate resilience. We can surely do this by adopting environmentally sound lifestyles, not by reverting to antiquated ways, but by creating a new synthesis, a new way of life that utilises modern technology and knowledge to protect the Earth’s environment from destruction and foster its renewal.

Finally, grappling with the problems of Bangladesh and keeping the country liveable is a daunting task. Even so, with clear vision and open mind, it can be done. Success will hinge on the courage of the government to make bold moves and resist the temptation of easy fixes. Once we adapt ourselves to the vagaries of climate change, as well as achieve the balance of a liveable environment, life will be worth living for our children and grandchildren.

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

Advanced science, Disasters - natural and man-made, Environmental, International, Life as it is, Technical

Amid global warming – why are we in a deep freeze?

Obverse effects of global warming

During winter, more often than not, a large part of northern United States is pummelled by an Arctic blast, sometimes severe, sometimes less so, that lasts for a week or two. But this winter’s blast plunged not only Midwest and Northeast into a deep freeze with bone-chilling temperatures as low as negative 45 degrees Celsius, but it also tested the mettle of millions of people living in the Deep South, particularly Texas, a state that seldom experience sub-zero temperature.

An onslaught of freak wintery weather—a cocktail of heavy snow, sleet and chilling ice storm—with sub-zero temperatures knocked millions of Texans off the power grid and plunged them into deep freeze, the lowest being negative 12 degrees in Houston. Frozen and burst water pipes in homes and businesses were widespread. Unlike northern states, Texas is not equipped to handle ice, sleet or snow. As a consequence, hundreds of vehicles, including dozens of 18-wheeler, were involved in horrific and sometimes fatal pileups on untreated icy roads.

The recent extreme weather is not limited to the United States. That is because when the winter is extreme in one part of the hemisphere, it is often extreme all across the hemisphere. Thus, the “beast” from the Arctic hit Europe too. In January, Spain experienced a deadly snow storm with dangerously low temperatures. Even a tropical country like Bangladesh, especially the northern region, could not escape the wrath of the cold wave.

Snow fell hard in Greece and Turkey, where it is far less normal. Snow also fell in Jerusalem and parts of Jordan and Syria, while snow-covered camels in Saudi Arabia made for a rare sight. We also had more than our fair share of snow. In the lower Hudson Valley of New York, where I live, Mother Nature already dumped around 36 inches of snow since the last week of January, with more in the forecast. Most of the snow—24 inches—fell in a single storm event from January 31 through February 2.

Climate change deniers have often used cold winter weather to advance their argument that global warming is a Chinese hoax. In one infamous example, when an Arctic freeze descended on the northeast, including New York City, in December 2017, former US President Donald Trump tweeted, “Perhaps we could use a little bit of that good old Global Warming to protect against” harsh winters. Only an ignoramus person like him could make such a stupid statement!

It may be counterintuitive, but paradoxically, among the many factors, anthropogenic climate change is mainly responsible for the short-lived bursts of extreme winter weather that we have been witnessing in recent years. Indeed, there is strong scientific evidence that rapid heating of the Arctic caused by global warming is pushing frigid air from the North Pole further down south due to distortion of the polar vortex.

Under normal conditions, cold air is concentrated in a huge low-pressure gyre around the North Pole in an area called the polar vortex—about 15 to 50 kilometres above the Earth’s surface in the layer of the atmosphere known as the stratosphere. When the vortex is strong, the jet stream—a narrow band of strong, fast-flowing wind in the upper atmosphere that generally blows from west to east all across the globe—acts as a barrier between the spinning cold air in the north and the warmer air to the south. As a result, cold air remains trapped in the Arctic, making winters in the northern mid-latitudes milder.

How does global warming distort the polar vortex? It is well-known that the rise in global temperature is not evenly spread around the world. Because of the loss of Arctic ice which otherwise would have reflected a substantial amount of solar radiation back into outer space, average temperature in and around the North Pole is increasing about twice as fast as in the mid-latitudes. This is known as Arctic Amplification. Several studies show that the amplification is particularly strong in winter. Consequently, a rapidly warming Arctic weakens the jet stream, which in turn weakens the polar vortex to the extent that it becomes distorted, thereby spilling its cold air southward.

According to meteorologists, in a span of two weeks from December to January, Arctic Amplification gave rise to a phenomenon called Sudden Stratospheric Warming, in which temperatures in the atmosphere 15 to 30 kilometres above the Arctic jumped by nearly 55 degrees, from negative 80 to negative 25 degrees. This accelerated warming weakened the jet stream considerably and subsequently distorted the vortex so severely that it got knocked off the pole, resulting in a sudden plunge in temperature south of the Arctic Circle all the way to the US-Mexico border. Hence, the once-in-a-lifetime cold winter in Texas and other southern states.

Continued rise in global temperature will not necessarily mean an end to bitter cold waves during winter any sooner. One group of researchers believe that Arctic blasts will still occur, but their intensity will depend on how much greenhouse gases we vent into the atmosphere. It is very probable that they will become rarer over time, but the ones we are experiencing now will more likely persist and last longer. Another group says that warming in the Arctic will increase the chances of frigid polar air spilling further south, leading to more periods of extreme cold days in the future, much colder than the ones we are experiencing now.

Nevertheless, the recent weather pattern clearly demonstrates that both extreme heat and extreme cold can happen side by side. Besides, two to four weeks of cold snaps do not make a winter. They are short-term weather events, while climate is about long-term trends. Arctic blasts are, therefore, not enough to compensate for the overall warming of the climate across the planet. In fact, last year was one of the hottest years on record, with the average temperature surpassing a number of all-time highs. And it occurred without the warming influence of El Niño.

Finally, we are in a deep freeze amid global warming because our “senseless and suicidal” romance with fossil fuels has fundamentally changed the global weather systems for worse.

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

Advanced science, Bangladesh, Disasters - natural and man-made, Economic, Environmental, International, Life as it is, Technical

Five years since Paris Accord: Are we any better?

Global warming and rise in sea level

Today marks the fifth anniversary of the Paris Accord hammered out by more than 190 countries at the 21st Conference of Parties (COP21). The core objective of the accord is to save humanity from the existential threat posed by climate change. To that end, the participating nations agreed to keep the increase in the average global temperature to within 2 degrees Celsius while endeavouring to limit it to 1.5 degrees by the year 2100. Besides pledging to temper the rise in temperature, they agreed to restructure the global economy, phase out fossil fuels over the coming decades, switch to renewable sources of energy, embrace clean technology, and most importantly, reduce greenhouse gas emissions to zero by 2050.

The Accord gives every country the ability to set its own goals to confront the climate crisis, in line with their specific situation. Moreover, instead of demanding expeditious and deep cuts in fossil fuel usage, it allows parties to peak greenhouse gas emissions “as soon as possible” followed by a gradual decrease in order to reach the zero emissions goal. It is patently evident that such a vague timetable fits the interests of the major polluters, including the United States, China and India. Nevertheless, beginning this year, each nation is required to reassess its own reduction plans once every five years. However, there is no consequence or penalty if a country fails to reassess or falls short of the pledged reductions.

The Accord also requires nations to address “loss and damage” caused by climate impacts. Since the wealthy, industrialised nations are largely responsible for the backlog of climate changing emissions lingering in the atmosphere, they should compensate poorer nations for unavoidable loss and damage. But even after COP25 held in Madrid last year (2019), wealthy nations are playing Jekyll and Hyde roles—promising to cover losses while dragging their feet on providing new finance.

We are now a full five years into the Paris Accord which, according to the former US President Barack Obama, is supposed to make the “world safer and more secure, more prosperous and more free.” Are we really on course to transform our planet into one as envisioned by Obama? Are we winning the race against climate change? Did we succeed in slowing down the damage resulting from climate change? By all accounts, the Accord did not make an iota of difference in decelerating the progression of our planet, and subsequently our civilisation, toward climatic meltdown. On the contrary, climate change and its deleterious effects are accelerating, with climate-related catastrophes piling up, year after year.

Our planet is now almost at the breaking point. The environmental changes sweeping across the world are occurring at a much quicker pace than five years ago. As the Earth warms, we are witnessing more cataclysmic wildfires turning forests into carbon dioxide emitters, not to mention calamitous floods inundating nearly half of landmasses in countries like Bangladesh, Maldives, Thailand and so forth. Persistent droughts, fierce storms and an increase in extreme weather phenomena—derecho, microburst, bombogenesis, Frankenstorm and many more—are on the rise. The fingerprints of climate change since 2015 can also be seen in the exacerbation of internal and international migration patterns of climate refugees.

Scorching heat waves, of all places, in the Arctic region, are now more frequent and long-lasting. It is quite likely that 2020 will be among the hottest years ever, even with the cooling effect of this year’s La Niña. Seas are warming and rising faster, putting more coastal cities at risk of going under acidic water. Warmer waters are wreaking havoc on marine organisms forcing them to migrate away from their familiar habitats. Glaciers are melting at an alarming rate, thus disrupting availability of freshwater.

Climate-induced mayhem is taking a heavy toll on the Arctic region. The amount of Arctic sea ice whose whiteness normally acts as a natural reflector of heat back out of the atmosphere is dwindling so rapidly that the region may soon become ice-free. Loss of ice is also changing the Arctic terrain—making it greener and prettier, but at the expense of releasing copious amounts of carbon dioxide and methane trapped in the frozen soil, which in turn is making global warming even worse. Additionally, scientists have found evidence that frozen methane deposits in the Arctic Ocean, worrisomely called the “sleeping giant of the carbon cycle,” are escaping into the atmosphere. In fact, northern landscapes are undergoing massive change, with potential ramifications not just for the Arctic itself, but the world as a whole.

Permafrost in cold climate countries is thawing at breakneck speed, releasing, just like Arctic ice, large amounts of long-stored carbon dioxide and methane. In addition, viruses and bacteria that had been buried under the permafrost for thousands of years are being released into the environment, posing health risks to humans and other forms of life. Also, deforestation of the Amazon rainforest in Brazil, a vital carbon sink that retards the momentum of global warming, has surged to its highest level since 2008.

As for peaking of emissions, there is a cavernous gap between the sharp cuts in emissions required to meet the goals of the Paris Accord and current projections. In a recent report, World Meteorological Organization (WMO), a specialised agency of the United Nations, states, “There is no sign of slowdown, let alone a decline, in greenhouse gases concentration in the atmosphere despite all the commitments under the Paris agreement.” Rather, emissions from just about every country are still on the rise, thereby making it difficult to close the gap so as to achieve zero emissions by 2050.

The report further notes that even the coronavirus-related drop in emissions failed to make much of a dent in the amount of heat-trapping greenhouse gases accumulating in the atmosphere. Consequently, WMO warns that the world risks becoming an “uninhabitable hell” for millions unless we drastically cut emissions—by at least 7.2 percent every 10 years if we want to keep the rise in temperature to 1.5 degree Celsius. Otherwise, we will soon be north of 3 degrees Celsius.

The warning from WMO is corroborated by a study published last month in the British journal Scientific Reports, in which the authors assert that we have already passed the “point of no return for global warming.” The only way we can stop the warming, the authors say, is by extracting “enormous amounts of carbon dioxide from the atmosphere.”

The Earth’s average temperature has already risen by roughly one degree since the advent of modern record keeping in 1880. The devastation caused by one degree rise clearly indicates that an additional 1.5 – 2 degrees Celsius rise before the end of this century will lock in the changes to the Earth’s climate system that will be beyond our adaptive capacity.

Five years ago, the then UN chief lauded the Paris Accord as a landmark agreement, a potent message from world leaders who had finally decided to take on climate change in earnest. Five years later, in a complete volte-face, the present UN chief, in a speech at Columbia University in New York, issued a searing indictment of our utter disregard for the pledges made in Paris. He said, “The state of the planet is broken. Humanity is waging a suicidal war on nature, facing new heights of global heating, new lows of ecological degradation….”

So much for the Paris Accord! No wonder environmentalists believe that the Accord is meaningless, and with good reason. Indeed, the toothless, nonbinding, non-enforceable accord is an oversold empty promise—a gentleman’s handshake applauding the imposition of a global climate regime on humankind that is harming the planet in the name of saving it.

Finally, world leaders should realise that fixing the climate is not about making pretty promises at grandiose conferences held in glamorous cities. And if we rely on grandstanding and farcical Accords that give us false hopes, we will lose the race to keep our planet cool and habitable.

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