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

World Population and Environmental Catastrophe

We are all aware of, indeed seriously concerned about, the climate change and global warming. The large majority of scientists – environmentalists, climatologists, atmospheric physicists, geophysicists, geochemists, oceanographers and experts of hosts of associated disciplines – as well as overwhelming proportion of human population unanimously hold the view that significant climate change is indeed taking place and that is all due to human activities. But then a small but powerful section of the population, mostly in America, reject this contention and assign changes to just natural activities. Obviously, these people have vested interests in deflecting away human activities.

It is blatantly obvious that human activities are the root causes of climate change. Of course, nature may be reacting to adverse conditions created by human beings, but the initial cause is human activity. One may ask, why is it that earth is reacting so disastrously over the last few decades when it existed in stable conditions for millions of years? The answer is undoubtedly ‘WE ARE’, there are too many of ‘US’ – human beings on the surface of the earth demanding, exploiting and extracting earth’s resources ruthlessly without any regard to its stability and sustainability.

Some 200 years ago or even 100 years ago we were doing what we are doing now – spewing out carbon dioxide and other global warming gases into the atmosphere – but that did not change climatic conditions irreversibly, because not enough of us had been doing the abusive actions. But now more than 7,500 million of us abusing the earth and probably pushed the earth to the threshold or beyond its sustainability.

The large human population of the present day is causing the problems. The United Nations’ estimation of human population from 1050 to 2017 is shown in Figure 1, where the past numbers had been compiled from human records and best estimate values. At no time until 1850 the global human population exceeded 1.0 billion. Around 1750, when Industrial Revolution took place, the Western World started using coal and other natural resources to improve living conditions and consequently the population started to grow significantly. From that time on, not only the standards of living started to improve but also better hygiene and improved medical sciences managed to bring down the death rate and thereby help increase population growth. At the moment the global population is 7.5 billion and growing at the rate of 80 million every year and this number is also growing! Since 1970, the global population had gone up by two-fold!

In 1960s and 1970s there were intense debates about the sustainability of the world population beyond about 3.5 billion, particularly with regard to food production. As estimated at that time that in about 12 to 15 years the population would grow by more than a billion (about 30% of the prevailing population). If so, could the food production be increased by about 30% in that time scale? The global population had been going up at that rate ever since despite all the measures taken to curtail it.

As the population grows, there are extra demands for housing and other socio-economic facilities and consequent shrinkage of arable land. But human ingenuity prevailed – multiple crop production, better yielding crop, crop rotation, disease resistant seeds and now GM crop etc – had improved food production. In fact, food production had been improved so much that food supply for the population is no longer an issue. But that had created more serious problems, particularly environmental problems, which need to be tackled.

Figure 1 Human population from 1050 to 2017

The United Nations have also produced a population growth projection for the years 1950 to 2100, as shown in Figure 2. Many factors affect population growth and incorporating various assumptions in those factors produce widely varying outcomes.  The middle thick green line is the outcome based on best estimate values, whereas the top and bottom lines are those with 95% level of confidence in various assumptions. If corrective actions such as proper family planning, better education and social responsibility of the population etc. are taken, the population growth could be limited to 9.6 billion in 2100, whereas unbridled growth will show a figure of 13.6 billion! The difference between two extremes in population numbers in 2100 is about 4 billion, more than 50% of the present population! That is an alarming prospect indeed!

Figure 2 Human population projection until 2100

Population distribution is not uniform round the world, as shown in Figure 3. At the moment over 60% (4.6 billion) of world population is in Asia and Africa constitutes 1.4 billion (less than 20%). But by 2100 the Asian population may remain same or even decline, whereas African population will shoot up to 4.4 billion, more than three times of the present population. This drastic increase will place enormous burden on the continent and may even lead to violent responses, unprecedented population migration to other continents etc. This situation will arise on top of ensuing environmental deterioration – global warming, extreme weather conditions etc.

Figure 3 Population growth by continents

It is interesting to note that China’s present population of over 1.42 billion would come down to about 1.06 billion by 2100, whereas India’s population would grow from 1.35 billion to 1.46 billion in the same time scale, as shown in Figure 4.  China’s drastic reduction in population is due to lower fertility rates which arise due to older population group. China had imposed two-child policy right from its inception and gradually it is bearing fruit.

Figure 4 Most populous countries

As already mentioned, population growth is multifactorial. But a very important factor is the economic condition of the country. A run away population growth stunts the economic growth of the country and at the same time a low economic growth tends to encourage higher population growth. A family tends to produce more children in a poverty-stricken country so that the children can look after the parents at their old ages. Thus, population growth and poverty form a vicious circle. Examples are Pakistan and Nigeria where large population growths are anticipated. On the other hand, Bangladesh is the country which has broken out of this vicious circle.

Let us get back to the aforementioned theme that climate change is primarily due to the presence of vast population. Coal extraction and its use by limited number of people catering for one or two billion people in the Western World in the 18th or 19th century was not that damaging to the climate. But, as deprived population of the East as well as other decolonised countries’ population are striving to improve living standards from abysmal depths, demand for natural resources like coal, gas, oil as well as minerals have gone up exponentially and environmental degradation followed the suit.

Nature has an inbuilt mechanism of correcting itself when there is any deviation or offset from the norm, which is commonly known as negative feedback. If there is an increase in temperature in the summer, more water from the sea would evaporate and subsequent rain would cool down the area. There are lots of factors acting in opposite phase to the initial condition to stabilise the natural conditions and that is the negative feedback.

But there may be situations when moderate negative feedback condition could breakdown and violent response would ensue. If due to excessive increase in global temperature, arctic and Antarctic ice caps melt, then there would be no seasonal cold stream of water, no moderation of summer temperature etc. In some areas the temperature would become so high that there would be almost spontaneous fire – as in Australia, California and even in Siberia. Condensation would be restricted to limited areas giving large increase in rainfall – as in England now – causing unprecedented floods etc.

So, either we pull ourselves back from the precipice by limiting and then reversing the damage that had already been inflicted to the nature or let nature go berserk threatening the very existence of human life or for that matter any form of life on earth.  

  • Dr A Rahman is an author and a columnist    

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

Abnormal of the past becomes normal of the future in climate change age

Sandbag embankment in Khulna, Bangladesh after the cyclone, Fani in 2019

For millions of years, we were in equilibrium with our environment. Over the past 11,500 years, a period in Earth’s history called the Holocene Epoch, there had been a global climatic stability with the average surface temperature fluctuating around one degree Celsius up or down. Our civilisation emerged and progressed against this backdrop of a relatively stable climate.

Melting glaciers

But then something happened that led to the change of whole edifice for worse. The Industrial Revolution that began around 1760 had drastically changed, indeed corrupted, our environment. Today, we live on a planet whose air is polluted, whose water is contaminated and whose soil is chemically altered. Indeed, human influence is so substantial that Earth is no longer in the Holocene Epoch, but rather in a new geologic epoch, the Anthropocene. For comparison, the epoch before Holocene, the Pleistocene Epoch, lasted nearly 2.5 million years.

Our insatiable appetite for energy using fossil fuel to have higher and higher living standards is placing unbearable burden on the planet. Until 1970s there had been little or no concern about the detrimental effects of extraction and use of fossil fuels on an industrial scale, particularly the amount of greenhouse gases that are released into the atmosphere.  The current concentration of carbon dioxide, the main greenhouse gas in the atmosphere, is about 415 parts per million. It is the highest concentration since the Pliocene Epoch, which extended from about 5.3 million to 2.5 million years ago.

We now live in a world where “abnormal” of yester-years have become “normal” of present day. Examples of present day normal that were abnormal some 50 years ago are Bombogenesis, Arctic Amplification, Hell Fire, Pyro-cumulonimbus Storms aka Fire Tornadoes, Heat Waves and Climate Refugees, Derecho, Sneaker Wave, Squall Line, Microburst, Frankenstorm, and so forth.

Under normal conditions, cold air mass sits above the poles in an area called the polar vortex. It is a large, low-pressure zone that exists at two levels of the atmosphere, one in the troposphere, where most of the weather-related phenomena occur, and the other a bit higher up, in the stratosphere, home of the ozone layer that protects us from the harmful effects of ultraviolet radiation. The vortices are seasonal atmospheric phenomena.

However, scientists believe that the phenomenon of Arctic Amplification, which is the self-reinforcing process that warms the Arctic and subarctic regions much faster than rest of the world, distorts the vortex in the North Pole, thereby resulting in a sudden plunge in temperature south of the Arctic Circle. This anomaly, a consequence of global warming, was abnormal before the 1970s, but quite normal today.

It is no longer implausible to have record snowfall and record high temperature on the same day. On November 16 of last year, Anchorage in Alaska saw its high temperature top out at plus seven degrees at 2:30 a.m. (Average November temperature in Anchorage is negative five degrees.) Before midnight that day, 21 centimetres of snow fell on the ground. This oddity, as well as 20-25 degrees swing in daytime temperature within 24 hours in the winter months—abnormal few decades ago—are normal now.

Located a few feet below the soil surface in extremely cold regions, permafrost is one of the most unique kinds of soil containing more carbon and methane than any other soil on Earth and twice as much carbon as is available in the atmosphere. But as global temperatures rise, Arctic permafrost thaws and greenhouse gases trapped in ice are released. Clearly, permafrost thawing is opening up additional pathways for greenhouse gases, constituting a newly identified, powerful feedback to global warming. Besides, ancient carcasses are emerging from the melting permafrost, and with them germs from illness long thought eradicated.

Nowadays, Australia and California are ground zero for out-of-control wildfires. As cataclysmic wildfires continue to rage across Australia, the loss of life—humans and animals—has reached staggering numbers. An estimated one billion animals have been killed so far and approximately 107,000 square kilometres—roughly 70 percent the size of Bangladesh—burned on the east coast.

Climate change is making heat waves longer and more frequent. Temperatures soaring over 50 degrees in many parts of the world are becoming the norm, while nice and comfortable weather has become the exception.

Some other wild weather phenomena due to climate change that were rare or considered abnormal in the past but not anymore are Derecho—a straight-line wind storm with hurricane-force winds; Sneaker Wave—a disproportionately large wave that suddenly appears during a wave sequence; Squall Line—a line of thunderstorms preceding a cold front; Microburst—severe downdraft caused by a thunderstorm; Frankenstorm—remnants of a super storm reinvigorated by an early winter storm and a blast of Arctic air.

Rising temperatures due to climate change is driving out oxygen from our oceans, threatening many species of aquatic life. According to the International Union of Conservation of Nature, around 700 ocean sites are now suffering from low oxygen, compared with 45 in the 1960s. Lest we forget, oceans are the source of most of the oxygen we breathe.

If the seas ever do rise by even a meter, our children and grandchildren may find themselves living cramped lives with other climate refugees on shrinking continents. “Humorously speaking,” they may even try to adopt the underwater lifestyle of the cartoon character SpongeBob SquarePants, provided ocean acidification caused by absorption of carbon dioxide has not already wiped him and his pineapple home from the bottom of the rising seas.

Few years ago, the sight of polar bears roaming the streets of a village or town would have been abnormal. Nowadays, it is normal because the land on which they live and hunt is under siege. As Arctic ice thins from melting, an occurrence linked to global warming, their habitat is shrinking and food supply is decreasing. As a result, they are moving out of their natural habitat and traveling hundreds of miles south of the Arctic region in search for food.

To tackle these and other new normals, every year since 1995, our leaders and/or their disciples have been meeting at various world capitals or cities, some of which are tourist hot spots―Bali, Cancun, Marrakech, Montreal, Paris―debating climate change in climate-controlled halls at the so-called Conference of Parties (COP). In order to feel what it is like living in one of the hottest places on Earth, maybe they should hold a future COP in halls without air conditioners in Jacobabad (Pakistan) during July when the average daytime temperature regularly surpasses 50 degrees.

The hype around these conferences is high, but expectations of the people are low because the proposals are not bold enough and interests of the developing countries are marginalised. Gone is the focus on establishing global “top down” approach for stabilising emissions of greenhouse gases that would be legally binding. On the contrary, focus is on voluntary “bottom up” commitments by individual nations to reduce emissions.

It has become clear that the much-touted Paris Agreement thrashed out at COP-21 for keeping the rise in global temperature this century to two degrees above pre-industrial levels and to pursue efforts to limit the temperature increase even lower to 1.5 degrees is on life-support system. America under Donald Trump has withdrawn from the Paris Agreement as Donald Trump categorises global warming as “fake news!” Subsequent summits, including COP-25 in Madrid two months ago, were stuck in a rut. There is no agreement yet and none is in sight.

The UN Secretary-General António Guterres roped in some world leaders, members of civil societies and corporate executives at a climate summit in New York on September 23, 2019 to highlight their plans to bring down greenhouse gas emissions to zero by 2050. As expected, they “prioritised” a laundry list of Action Portfolios without any firm commitment to implement them.

The star of the summit was Greta Thunberg, the 17-year old Swedish activist, who delivered a blunt speech, excoriating world leaders for their inaction. And the shameless world leaders clapped and cheered every time she chastised them with phrases like “How dare you,” or “You have stolen my dreams and my childhood with your empty words.” If they had any self-respect, they should have hung their head down in shame instead of applauding. They did not do so because they are “normal” 21st century leaders.

All said and done, what is the end game? Can pre-emptively embarking on a revolutionary change that will lead us away from dependency on fossil fuels and embracing eco-friendly renewable energies save our planet? Can we avoid the risk of a catastrophic failure of our increasingly ephemeral and tightly interlinked global civilisation as we know it? The answer to the above questions is NO, because our leaders lack the collective will to take the decisive steps required to keep our planet liveable for the future generations.

Scientists believe that if we started to cut down on emissions of carbon dioxide even by one percent in 1990, tackling climate change would have been manageable. Instead, we wasted 30 years by inaction. The inertia of the climate system is such that even if we stop introducing greenhouse gases into the atmosphere right now, the ones already in the atmosphere will keep on warming the Earth for another one to two hundred years before equilibrium is reached. In other words, climate change would keep on accelerating, regardless of what measures we take to mitigate its effects.

We can, however, partially solve the seemingly unsolvable problems we have created by changing the unsustainable lifestyle of many of us. More importantly, we have to work to address the problem of the world’s ever-growing population. We are probably within a few decades of a point in time where the sheer number of people on Earth will make continuing degradation of our planet irreversible. So, it is up to us whether we choose to take actions in a direction which will reduce overall global population.

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

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, Environmental, International, Technical

Arctic Freeze and Global Warming

Even a tropical country like Bangladesh couldn’t escape the wrath of the distorted polar vortex. 

Arctic blast

During winter, more often than not, a large part of northern United States is hit by an Arctic blast, sometimes severe, sometimes less severe, that lasts for a week or two. But this winter’s blast plunged not only the Midwest and the Northeast into a deep freeze with bone chilling temperatures as low as negative 25 degrees Celsius ‒ negative 35 degrees with wind chill, it also tested the mettle of millions of people living in the Deep South ‒ from Texas to Florida to the Carolinas ‒ who seldom experience sub-freezing temperature. In the midst of the cold spell, a rapidly intensifying cyclone, known as bombogenesis or “bomb” cyclone triggered by an extreme drop in atmospheric pressure, dumped 15-25 centimetres of snow in the Northeast while winds were howling at 80-120 kilometres per hour. This was followed by another winter storm that blanketed the Upper Midwest and parts of New England in the Northeast with wind-driven snow, freezing rain and sleet.

Unsurprisingly, the unforgiving Arctic freeze and record-breaking temperatures prompted Donald Trump, the cheerleader of climate deniers, to tweet, “In the East, it could be the COLDEST New Year’s Eve on record. Perhaps we could use a little bit of that good old Global Warming that our Country, but not other countries, was going to pay TRILLIONS OF DOLLARS to protect against. Bundle up!”

Trump’s favourite news source, the conservative Fox News Channel, probably failed to alert him that while we were shivering in the sub-zero temperatures, residents of Alaska, historically the coldest state during winter, were enjoying a relatively balmy weather, with temperatures most of the times staying above the freezing mark. And for information of those dancing to the tunes of their cheerleader who is “ignorant of his own ignorance” about global warming, extreme hot days in the U.S. over the past 365 days are beating extreme cold days by three to one, notes the climate change tracking platform Climate Signals.

Leading an administration without a science adviser, Trump seems to have no awareness whatsoever that the cold snap covered barely one percent of the Earth’s surface. He was also unaware that while the United States was experiencing record-breaking low temperatures, some regions in Australia were experiencing hottest weather in nearly 80 years with temperatures in Sydney hitting as high as 47.3 degrees Celsius.

In fact, despite a frigid December, last year was one of the hottest years on record, surpassing a number of all-time global heat records. Moreover, it occurred without the warming influence of El Niño that helped boost the global temperature to record levels the previous two years. Furthermore, notwithstanding the blustery Arctic freeze, the average temperature in New York and surrounding areas so far in January is five degrees Celsius ‒ almost twice the average for this time of the year.

Clearly, Trump’s tweet tells us that he doesn’t understand the difference between weather and climate. Weather is a local phenomenon, describing what happens in a particular region on a shorter time scale, such as the Arctic blast we recently went through. Climate on the other hand refers to how the atmosphere acts over a long period of time. Simply put, climate can be thought of as the cumulative average of many variables of the atmosphere, oceans and landmasses, such as temperature, rainfall, or snowfall, or extent of snow cover, over many years. Therefore, it takes much longer than one season of bitter cold, not two or three weeks, to have any long-term effect on the climate.

Although it may sound counterintuitive, extreme cold spells in the Northern Hemisphere are caused, at least in part, by climate change, global warming in particular. How? The answer lies in the cold air mass, which under normal circumstances, sits above the poles in an area called the polar vortex. It is a large, low-pressure zone that exists at two levels of the atmosphere, one in the troposphere, where most of the weather phenomena occur, and the other a bit higher up, in the stratosphere, home of the ozone layer that protects us from the harmful effects of ultraviolet radiation. The vortex rotates counter-clockwise at the North Pole and clockwise at the South Pole. The vortices are seasonal atmospheric phenomena not necessarily created by global warming.

However, scientists believe that global warming distorts the vortex in the North Pole, thereby resulting in a sudden plunge in temperature south of the Arctic Circle. That’s because increases in global temperature are not evenly spread around the world. They are greater on land and at higher latitudes. Consequently, on average, Arctic temperatures have increased in recent decades at about twice the global average. The picture for Antarctica is less clear because the Antarctic climate has behaved differently in different regions and seasons.

As a result of warming, more ice of the Arctic Ocean is melting during the summer months. Recently declassified data from the U.S. Navy nuclear submarines operating under the polar ice along with many oceanographic studies suggest that the summertime coverage of Arctic Ocean’s ice has declined some 25 percent since 1979, with more modest but still significant declines in other seasons.

As the ice melts, the Arctic ice sheets reflect less sunlight, causing the Arctic Ocean to absorb more heat, which it then releases into the atmosphere, adding to warming. This process, and other Arctic feedback loops, are known as Arctic Amplification. Eventually, the amplification has a ripple effect extending well into the stratosphere, weakening and distorting the polar vortex, thus allowing the air to escape south. In other words, instead of staying where it belongs in winter, closer to the Arctic Circle, the air moves down south into continental United States, Europe and Asia. Hence, the extreme cold spells.

Even a tropical country like Bangladesh couldn’t escape the wrath of the distorted polar vortex. On 7 January 2018, the country recorded the lowest temperature in five decades as mercury nosedived to a chilling 2.6 degrees Celsius in Tetulia.

While climate pundits are predicting that our planet could warm, on average, roughly two degrees Celsius by the end of the century, we should not interpret that to mean an end to bitter cold waves during winter any sooner. Arctic blasts will still occur, but depending on how much greenhouse gases we dump into the atmosphere, they will become rarer over time.

Nevertheless, the message from the recent Arctic blast is loud and clear. Our romance with fossil fuels have fundamentally changed the global weather systems to the point where we have to do something drastic if we want to live on the only habitable planet in the solar system beyond the twenty-first century.

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