Rains of reckoning and mad monsoons
A glance at a weather page on social media is enough to tell you how people in South Asia anticipate the monsoon season. Rain is nothing short of an individual and national celebration in Pakistan too, but it transforms into chaos when it brings flooding, power outages, broken roads, damaged infrastructure and even deaths. Why has the much-loved monsoon become deadly and disastrous? What is causing above-normal rainfall? What is the reason behind the unprecedented weather patterns? Can it get worse?
With each passing year, we are becoming increasingly affected by climate change and its impacts seem to be never-ending, be it more intense heat waves or erratic rains. The coastal belts have also seen more cyclones in the last 15 years as compared to 100 years in the past.
Like many urban areas across the world, Karachi has seen an increase in average temperature over the past few decades as a result of a mix of localised factors including urbanisation and global climate change. Mostly as a result of greenhouse gas emissions, the average global temperature has risen by around 1.1°C to 1.2°C since the late 19th century as of 2020.
“The climatic situation that the country is in presently and why cyclones have not hit Karachi as intensely is due to its geographical location, winds, and the historical trajectory,” explained Afia Salam, a climate and environment expert, who holds a Masters in geography. “The frequency of cyclones has increased in the last few decades, and if numbers are to be believed then in the last 100 years we have administered 5-6 big cyclones, and in [just] the last 15 years we have seen about [the same number of cyclones].”
Chief Meteorologist at Pakistan Meteorological Department Dr Sardar Sarfaraz further explained that the city has been hit by cyclones and storms in the past. “If history is to be believed, the biggest on-record cyclone was in 1902, followed by one in 1906, and then in 1964 and 1986,” he said. “Now the situation has changed a great deal with the infrastructure of the city and climate change impacts.”
Historical records show that during the last 100 years, several cyclonic storms have hit Pakistan’s coastal areas, such as in 1895, 1902, 1907, 1948, 1964, 1985, 1999, 2001 and 2007. In 1964, a cyclonic storm caused great loss of life and property in Hyderabad and Tharparkar districts as it moved northeastward and entered into southeastern areas of Sindh. During a short span of six years, three cyclonic storms — two in 1902 (May 13 and June 16) and one in 1907 (June 6) struck the coast near Karachi. The other two cyclonic storms in 1895 and 1984 struck the Makran coast near Pasni and Jiwani respectively.
A tropical cyclone (TC 02A) in 1999, having directly hit the coastal areas of Sindh near Badin/Thatta districts, caused 700 casualties besides other damages worth $600 million. Similarly, TC Yemyin - which had hit the Makran coast near Pasni in 2007 - inflicted damages worth $560 million, and 950 human lives. In 2007 apart from TC Yemyin, Pakistan’s coastal area remained under persistent threat from TC Gonu, the strongest cyclone ever in the North Arabian Sea, which finally hit the Oman coast, causing over $200 million in losses in oil exports.
In 2010, the TC Phet killed 44 people, 24 in Oman, 15 in Pakistan, and five in India with other infrastructural damages of around $780 million.
“Whether the cyclones hit Karachi or not, the coastal belt gets affected, be it Thatta or Badin in Sindh or the 7,500 km long coastal belt of Balochistan,” said Salam. “The intensity of the cyclone is not understood because it usually hits less-populated and under-developed areas whereas if it hit Karachi, it would be disastrous due to several factors including infrastructure, population, etc.”
“As an individual one cannot stop the cyclone, but one should at least take the predictions seriously and not make fun of the Met office predictions,” she adds, pointing out that this is a moving science that changes every hour and every minute. “Wind direction is the main reason behind cyclones and their movements, but mostly the first notification is taken seriously by everyone, and the rest is not taken seriously, so that the Met department’s releases every hour are not followed.”
Just as the winds change a bit, the direction of the cyclones changes too - as well as its intensity. There are several stages involved. At first, it can be a storm that changes into a cyclone. Then there could be a hurricane, a tropical hurricane, or a thunderstorm - all depending solely upon the intensity of winds and direction.
“It’s not that Karachi is on the safe side as we have experienced a tsunami hitting Karachi’s shore,” said Salam.
Cyclones have struck Karachi in the past, and in recent years, the city has also experienced damage due to these storms. However, the problem is that the city has expanded so much that its outskirts are often overlooked when assessing the full impact of these events.
Other than cyclones another major problem at hand is the increasing heatwaves that are causing more and more rains. “The geographical monsoon has changed in the country due to heat intensities,” said Salam. “We have seen more rains in south Punjab in 2022, which is a clear indication of climate change,” she added.
Over the previous century, Karachi has seen an average temperature increase of between 1.5°C to 2°C. There are various reasons why this rise is marginally more than the average for the world. Higher local temperatures are a result of Karachi's rapid urbanisation, growing concrete infrastructure, and deforestation. Cities such as Karachi warm up more quickly than rural areas due to urban heat islands.
The numbers show that the amount of rainfall (in millimetres) that used to fall over six years is now occurring over 15-20 days and the whole monsoon shift is due to climate change as more heat means more evaporation and cloud formation and eventually more rain. The environment has started affecting us in every possible way from rains to cyclones and to seasonal shifts. “In the last three years, spring season has almost vanished where (Karachi experiences) summers right after winters which has affected crops at a significant change,” said Salam. “We are in a transition of climate change and we can’t help but try to analyse and understand it, because we have no data and no in-hand research on this, and nothing to rely upon.”
Seasonal shifts have affected crops tremendously and to work on anything one needs at least a 30-year cycle to be able to implement any plans, it is yet too early to take any actions. The Arabian Sea has historically been the source of Karachi's cyclones. Even while cyclones don't occur very often in Karachi, when they do, they may be extremely dangerous and result in fatalities, property damage, and major floods. Improved preparedness and forecasting over time have lessened the effect of cyclones on the metropolis. The city of Karachi and the surrounding environs have seen milder cyclonic occurrences in the past because of its location on the Arabian Sea coast. Even though the Arabian Sea experiences fewer cyclones than the Bay of Bengal, several of them have affected Karachi.
In the last two years, Karachi has seen two cyclones; neither hit Karachi at full intensity (the intensity of the cyclone was broken due to the winds direction) but they did damage other parts of the country. To understand why it didn’t hit Karachi we have to understand that it all is connected to upper air (air direction above the sea level) and that can go from 35-45 knots. “The whole cyclone science is not on the ground but in the air and it changes everything in seconds,” explained Sarfaraz. The Met department monitors it minute by minute and keeps updating. For example, in 2023, when Biparjoy was to hit Karachi, it changed its direction towards Gujrat, India just 450 km away from Karachi and it took a recurve due to winds.”
This is the subtropical ridge – impossible to predict as the wind’s speed and direction change rapidly. The recent cyclone started forming near Badin South, but the winds changed direction from southeast to northwest. It could have hit Karachi but the winds changed it from east to west. “Coastal geography is not linear and cannot be plain like other weather conditions where one can predict for a week or month,” Sarfraz added.
In recent years, climate change has made rainfall increasingly unpredictable. The weather patterns have shifted from established norms, with Pakistan experiencing heavy rains and flooding in 2022 followed by below-average rainfall in 2023. This year, once again, there has been a surge in rainfall.
“If climate predictions are to be believed, we may see that, on an average, 15-25 mm rains are expected to increase,” said the chief Met officer. "It's difficult to provide an exact figure for rainfall conditions as we are transitioning into a climate-affected nation. However, to give a sense of the impact: a one-degree rise in surface temperature leads to about a seven percent increase in moisture, which ultimately results in heavier rainfall."
"In our country, we've witnessed extreme contrasts in weather — temperatures dropping below freezing in the north while heatwaves strike the south," he pointed out.
On a larger scale, many initiatives have been launched, such as the Intergovernmental Panel on Climate Change (IPCC) warning scenarios to help understand which emission level of carbon we are on. “As it is predicted that by 2050-2070 if the world is in a low emission scenario then 1.5-2 degrees are expected to rise while in a medium scenario, 2-3 degrees,” shared Dr Sarfaraz. “But in a high emission scenario 4-5 degrees are expected to rise, and this is the overall temperature of the earth including both sea surface and land.”
Many studies show that the temperatures of the world have risen 1.2 degrees since the pre-industrial era and on average it is expected to rise 0.2 degrees per decade. However, if we look at the numbers, over the last 63 years, Pakistan's average temperature has risen by 0.18 degrees per decade. In contrast, Karachi alone has experienced a 1.34-degree increase, which is nearly double the national average. “Many factors that lead us here are deforestation, urban infrastructure, carbon emission, and population,” he added.
“This year, the rain was exceptional but not disastrous as we have touched above-average rains and in some places, the situation changed into floods. Interior areas of Punjab and Sindh has seen damages, and up north we have also seen rains,” explained weather expert Jawad Jawaid. He also said that overall, this season was erratic.
July had a monsoon that was below normal across the country but by the middle of August, there were 2-3 rain systems that equated the others, especially the last one which turned into a cyclone that caused the rains to go above normal.
“Monsoon season will keep moving towards unpredictability due to global shifts and climate change which we try to monitor daily, but then again they don’t fall into the prediction at all,” he elaborated on weather patterns. “Between 2019 and 2022, the rains were above normal, in 2023 rains were low and again in 2024, above average across Pakistan. Scattered rain has been seen in the last 2-3 years. We had below normal rains last year but this year we are above normal. Since the last 6-10 years we are not on average and there is no stability and pattern found. “We know that in the next few years, we will have to face the frequency of ups and down, each season will go extreme, either negative or positive.”
Karachi’s love-hate relationship with cyclones
There is a scientific explanation for this. The entire coastline of Sindh, along with its nearby areas, consists of shallow waters. When a cyclone enters these shallow waters, it gradually loses intensity, as such systems tend to weaken in shallower areas. “Such cyclonic systems are most power-hungry when they form and mostly when they come towards shallow waters, they change their directions and winds add up to it because cyclones are attracted more towards heat,” the weather expert explained. “Shallow waters do not provide them the right atmosphere and heat that it requires to intensify.”
He also pointed out that Karachi is located at the longitude and latitude of 20 and 21 N when any such cyclone system crosses, they face vertical wind share a lot.
“Vertical wind share is a powerful wind in the upper atmosphere, around 18-20 km above a cyclone, that alters its direction or intensity,” says Jawaid. “This wind can disrupt the cyclone by breaking up its clouds and reducing its strength.
He explained that this vertical wind share was very low and that is why cyclones have caused high rains in lower Sindh and Tharparkar. “One thing that needs to be understood that we can’t be lucky every time, the winds can change and it can cause disaster,” he warned.
Heatwaves have become increasingly powerful and longer, especially in South Asia, as a result of the wider effects of global warming. Karachi has seen extreme heat waves in the past few years. One such instance was in 2015 when highs of approximately 45°C led to a considerable number of heat-related fatalities. The frequency and intensity of these heat waves have increased, underscoring the effects of rising temperatures on the metropolis.
“A partial connection is there with heatwaves and rains, mostly the reason is when heat indexes are raised like this year with heat indexes at 50-60 degrees, while the temperature was 42 max,” he pointed out. “The core reason is that Arabian Sea surface level temperature was above normal, causes humidity increases, and we will see this phenomenon more frequency in next few years.”
Due to the rising surface temperatures of the Arabian Sea, the frequency and intensity of cyclones are increasing. After the Bay of Bengal, the Arabian Sea is becoming the next powerhouse for cyclones. This is why cyclones are now reaching regions where rainfall was previously unexpected. “This year we have seen the cyclones moving towards Oman, UAE, Saudia, Yemen, Balochistan which are all those regions where it never rained in monsoon. This is a prime example of climate change,” he revealed.
Karachi's temperature rise is in line with the worldwide trend of warming, but it is more noticeable because of local elements including its proximity to the shore, dense population, and dearth of greenery. “We can’t stop floods, cyclones, and rains but we can control what triggers them and intensify them,” says Jawaid. “In Karachi, there should be at least 20-25 percent of plantation while in reality there is only 2-3 percent.”
In contrast, locations with lower levels of urbanisation or those that have adopted climate mitigation measures typically experience slower increases in global temperatures.
Increased energy use, water shortages, and a heightened risk of heat-related illnesses are just a few of the negative effects this temperature rise has had on the environment and public health in Karachi.