Extreme weather: the technologies used to combat climate change

At the end of last year, the United Nations Foundation reflected that 2022 was a “split screen” in terms of climate change. The world, it said, had taken “several important steps to curb the climate crisis while its impacts continued to worsen”, reminding us of the “increasingly severe and irreversible consequences” of an increase in temperature with floods, record-breaking heatwaves, severe drought in Africa, forest fires and cyclones throughout the year.

Cyclones 

Cyclones are tropical rainstorms with strong, rotating winds, formed when low pressure is created in the oceans near the equator. 

Thunderstorms move across the surface of the ocean and if the surface water is warm (i.e. 27°C/80°F), the storm sucks up the heat energy from the water and carries it in the converging winds. The warmer the water, the more moisture in the air. 

In June 2023, Cyclone Biparjoy became the longest cyclone to have crossed the Arabian Sea. It lasted 13 days and three hours, more than double the typical duration of six days and three hours. It hit the densely populated areas of the port of Gujarat, Rajasthan and Madhya Pradesh in western India and moved on to Karachi, Pakistan. Winds of up to 160km/h (100mph) brought heavy rain, strong winds and coastal storm surges. As it moved inland, farmland was swamped, towns and cities were flooded and there were power outages. 

The Council on Energy, Environment and Water (CEEW), based in New Delhi, warned that cyclones and storm surges have intensified and occurrences have increased three-fold between 1970 and 2019 in the Odisha and Gujarat regions. It reported that Arabian Sea cyclones have “battered India’s west coast at the rate of one per year since 2018, a frequency not seen in five decades”. Studies have shown that cyclones in this region are becoming stronger and wetter.

The CEEW estimates that surface temperatures over the Arabian Sea have increased by between 1.2 and 1.4°C in the last 20 years, with scientists claiming that the temperatures in the ocean’s lower layers are also warming, increasing at a rate of 13.4 millidegrees per year since the mid-1990s. This is indicated by the occurrence of category 4 cyclones, which only began appearing in the Arabian Sea after 1995.

Longer, stronger

The UN’s Intergovernmental Panel on Climate Change (IPCC) has reported that warmer oceans not only increase the likelihood of cyclones developing but make them more slow-moving. This brings a longer duration of rainfall and wind, causing more damage than a fast-moving one.

In May 2023, Cyclone Mocha reached Myanmar. It was a category 5 storm, with winds of 280km/h (175mph) and was the joint-strongest on record in the North Indian Ocean basin. 

Two months earlier, Cyclone Freddy hit Malawi, Madagascar and Mozambique, depositing six months’ rainfall in six days. More than 1,000 people were reported killed or missing as river banks burst and floods washed away homes and destroyed crops.

Technology to combat cyclones

Olav Hollingsaeter, a retired Norwegian Navy submarine officer, is founder and CEO of OceanTherm, a company developing bubble curtains to mitigate tropical cyclones. 

This system of giant, perforated pipes is transported to a target area by ships, where large compressors pump cold air into the ocean to cool the surface temperature. Each ship can operate a mile-long bubble curtain, Hollingsaeter explains. He envisages a fleet of ships maintained in strategic locations that can be activated quickly and operate in formation. 

“Our research suggests that a system can cover a large enough area to reduce the temperature in the water column between 100m [320ft] in depth and the surface in the path of an incoming tropical cyclone,” says Hollingsaeter.

The reduced surface temperature spreads out from the ocean current. The higher the speed of the current, and the longer the period of operations, the further the effect will spread, he continues. The bubble curtain may stop the storm from making landfall or at least prevent it from intensifying and developing into a stronger hurricane.

The system is still in the developmental stage. The next phase is to combine a simulation model to evaluate the effect on historical tropical cyclone scenarios.

Flooding

A monsoon is caused as warm air rising from the equator flows towards the poles, cools and returns to the subtropics. This Hadley circulation of airflow leaves a region of low pressure, where the water vapour cools, forming rain clouds. 

El Niño is a climate pattern that describes the warming of surface waters in the Pacific Ocean every two to seven years. The US National Oceanic and Atmospheric Administration (NOAA) says there is a 56% chance that when El Niño peaks later this year, it will raise the sea surface temperature of the Eastern Pacific at least 1.5°C. The opposite climate pattern is La Niña, which cools the surface temperature.

Rising danger

There is no consensus among scientists that El Niño will affect the amount of rainfall in a monsoon. The strongest El Niño, in 1997-98, had little effect on that year’s Indian monsoon. Historical data shows a decrease in global monsoons until the 1980s when activity first stabilised and then began to increase.

Flooding causes damage to transport systems, communication and power systems as well as destroying crops, livestock and wildlife, and can spread waterborne disease and pollutants.

Australia has experienced severe heavy rains and flooding in recent years. Queensland and New South Wales (NSW) experienced flooding in February 2023, for the third year in a row. In March, Cyclone Gabrielle caused a flood emergency that lasted for 177 days in Queensland and NSW before hitting New Zealand’s North Island, Vanuatu, Solomon Islands and Norfolk Island.  

There have also been torrential rains and flooding in central and south-west China and there are flood warnings in place in the north of the country. 

In South Africa, KwaZulu-Natal was flooded in March 2023 and again in June, when 176mm of rain fell in 24 hours. 

Heavy rainfall in a short period leads to flash floods when the water cannot be absorbed by the ground or drained away. Rivers burst their banks and flooded towns and cities in Romania in February. 

Flash floods can also be caused by fast-melting ice sheets or glaciers, as was the case in Pakistan in 

June as Cyclone Biparjoy swept through. World Weather Attribution said the climate crisis may have increased the intensity of rainfall by up to 50%, in relation to a five-day downpour that struck the provinces of Sindh and Balochistan.

Technology to combat flooding

Researchers at the Institute of Geodesy and Geoinformation at the University of Bonn, Germany, have developed a system of sensors, operated with solar cells, which monitor river water levels and transmit data to an evaluation centre using a global navigation satellite system (GNSS) receiver and antenna. The sensors are reliable, cost-effective (around €150) and do not need any maintenance. The receiver and antenna at the heart of the system are also low cost, explains Dr Makan Karegar at the university. 

Signal waves transmitted by satellites are partially picked up directly by the antenna, and the rest are reflected from the surface of the water. The reflection means these signals have a longer path, and when this data is superimposed on the directly received signal, the interference can be used to calculate the distance between the water level and the antenna.

The system has been installed in Wesel in North Rhine-Westphalia. The GNSS antenna can be attached to a bridge, building, tree or fence next to the river, says Karegar. It is able to measure the river level around the clock without any contact and transmits data via a mobile network. It is accurate to within 15mm. While this is less accurate than a radar sensor, it is sufficient for flood alerts and considerably cheaper. It is suitable for rivers at least 40m wide. “This is the smallest radius from which the antenna can receive the reflected satellite signal,” Karegar says. “If the watercourse is too narrow, most of the reflected signals come from the land.”

Heatwaves 

On 3 July 2023, the world’s hottest day was recorded by the NOAA. The average global temperature of 17.01°C exceeded the record of 16.92°C set on 24 July 2022. This follows the eight warmest years on record, even with a cooling La Niña for the past three years, which has acted as a temporary brake on global temperature increase, says the secretary-general of the World Meteorological Organization, Professor Petteri Taalas. 

The world’s average air temperature fluctuates between 12 and 17°C and has averaged 16.2°C at the beginning of July since 1979. Scientists point to a combination of climate change and this year’s El Niño for the increase. 

Beijing recorded its hottest June day since records began, and parts of northern China sweltered in 40-degree heat. In north Africa, there have been temperatures of 50°C, and a heat dome in the southern US has resulted in temperatures breaking 43°C this summer. 

Europe has experienced consecutive heatwaves as anti-cyclone Cerberus sweeps Italy and southern parts of Spain, with temperature highs of 44 to 48°C. The record temperature of 48.8°C was experienced in Floridia, Sicily, in 2021. 

Forest fires

Increasing temperatures make vegetation dry and easy to ignite, whether triggered by electrical storms, careless tourists or acts of arson. 

There have been forest fires this year in Canada’s Northwest Territories following a heatwave when temperatures reached 37.4°C.

There were 420 active forest fires in July across the region, of which 150 are in Quebec. So far this year, 4.4 million hectares have been burned. Forest fires also raged in Thailand, across Khao Nang Dam forest park, north-east of Bangkok, in March.

Chile was subjected to 407 active forest fires that affected 43,000 hectares from 30 January to 20 February this year. 

In 2021, after 10,000 wildfires burned more than four million acres the previous year, California officials began to thin out forests to create fire breaks. Environmental groups protested that native plant species were being destroyed. Energy companies were also urged to maintain power lines and vegetation around them to avoid contact with extremely dry vegetation.

And, at the time of writing, a heatwave across southern Europe and the Mediterranean has resulted in mass evacuations of holiday-makers in Greek islands such as Evia, Rhodes and Corfu, as life-threatening forest fires take hold.

Technology to combat forest fires

An ‘Internet of Trees’ has been developed by Silvanet using solar-powered wildfire sensor nodes with LoRaWAN (long-range wide-area network) technology and machine learning to monitor forest areas and detect wildfires. The sensor nodes are linked to the internet via the Silvanet Border Gateway at the edge of the forest using 4G, 2G or GPRS connectivity.

Drought

El Niño disrupts the usual supply of moisture, causing heavy, prolonged rain in some areas and severe drought in others. 

This year saw the continuation of the longest drought in 40 years in the Horn of Africa, affecting Somalia, Ethiopia and Kenya. The rainy season was the driest the region had seen for 70 years and crops failed again as the Horn saw its sixth failed rainy season. This year also saw Madagascar endure its fourth drought in as many years. Malawai has experienced its second consecutive crop failure this year, and Namibia and Zambia have both seen below average rainfall.

At the end of last year, the United Nations Foundation reflected that 2022 was a “split screen” in terms of climate change. The world, it said, had taken “several important steps to curb the climate crisis while its impacts continued to worsen”, reminding us of the “increasingly severe and irreversible consequences” of an increase in temperature with floods, record-breaking heatwaves, severe drought in Africa, forest fires and cyclones throughout the year.

Cyclones 

Cyclones are tropical rainstorms with strong, rotating winds, formed when low pressure is created in the oceans near the equator. 

Thunderstorms move across the surface of the ocean and if the surface water is warm (i.e. 27°C/80°F), the storm sucks up the heat energy from the water and carries it in the converging winds. The warmer the water, the more moisture in the air. 

In June 2023, Cyclone Biparjoy became the longest cyclone to have crossed the Arabian Sea. It lasted 13 days and three hours, more than double the typical duration of six days and three hours. It hit the densely populated areas of the port of Gujarat, Rajasthan and Madhya Pradesh in western India and moved on to Karachi, Pakistan. Winds of up to 160km/h (100mph) brought heavy rain, strong winds and coastal storm surges. As it moved inland, farmland was swamped, towns and cities were flooded and there were power outages. 

The Council on Energy, Environment and Water (CEEW), based in New Delhi, warned that cyclones and storm surges have intensified and occurrences have increased three-fold between 1970 and 2019 in the Odisha and Gujarat regions. It reported that Arabian Sea cyclones have “battered India’s west coast at the rate of one per year since 2018, a frequency not seen in five decades”. Studies have shown that cyclones in this region are becoming stronger and wetter.

The CEEW estimates that surface temperatures over the Arabian Sea have increased by between 1.2 and 1.4°C in the last 20 years, with scientists claiming that the temperatures in the ocean’s lower layers are also warming, increasing at a rate of 13.4 millidegrees per year since the mid-1990s. This is indicated by the occurrence of category 4 cyclones, which only began appearing in the Arabian Sea after 1995.

Longer, stronger

The UN’s Intergovernmental Panel on Climate Change (IPCC) has reported that warmer oceans not only increase the likelihood of cyclones developing but make them more slow-moving. This brings a longer duration of rainfall and wind, causing more damage than a fast-moving one.

In May 2023, Cyclone Mocha reached Myanmar. It was a category 5 storm, with winds of 280km/h (175mph) and was the joint-strongest on record in the North Indian Ocean basin. 

Two months earlier, Cyclone Freddy hit Malawi, Madagascar and Mozambique, depositing six months’ rainfall in six days. More than 1,000 people were reported killed or missing as river banks burst and floods washed away homes and destroyed crops.

Technology to combat cyclones

Olav Hollingsaeter, a retired Norwegian Navy submarine officer, is founder and CEO of OceanTherm, a company developing bubble curtains to mitigate tropical cyclones. 

This system of giant, perforated pipes is transported to a target area by ships, where large compressors pump cold air into the ocean to cool the surface temperature. Each ship can operate a mile-long bubble curtain, Hollingsaeter explains. He envisages a fleet of ships maintained in strategic locations that can be activated quickly and operate in formation. 

“Our research suggests that a system can cover a large enough area to reduce the temperature in the water column between 100m [320ft] in depth and the surface in the path of an incoming tropical cyclone,” says Hollingsaeter.

The reduced surface temperature spreads out from the ocean current. The higher the speed of the current, and the longer the period of operations, the further the effect will spread, he continues. The bubble curtain may stop the storm from making landfall or at least prevent it from intensifying and developing into a stronger hurricane.

The system is still in the developmental stage. The next phase is to combine a simulation model to evaluate the effect on historical tropical cyclone scenarios.

Flooding

A monsoon is caused as warm air rising from the equator flows towards the poles, cools and returns to the subtropics. This Hadley circulation of airflow leaves a region of low pressure, where the water vapour cools, forming rain clouds. 

El Niño is a climate pattern that describes the warming of surface waters in the Pacific Ocean every two to seven years. The US National Oceanic and Atmospheric Administration (NOAA) says there is a 56% chance that when El Niño peaks later this year, it will raise the sea surface temperature of the Eastern Pacific at least 1.5°C. The opposite climate pattern is La Niña, which cools the surface temperature.

Rising danger

There is no consensus among scientists that El Niño will affect the amount of rainfall in a monsoon. The strongest El Niño, in 1997-98, had little effect on that year’s Indian monsoon. Historical data shows a decrease in global monsoons until the 1980s when activity first stabilised and then began to increase.

Flooding causes damage to transport systems, communication and power systems as well as destroying crops, livestock and wildlife, and can spread waterborne disease and pollutants.

Australia has experienced severe heavy rains and flooding in recent years. Queensland and New South Wales (NSW) experienced flooding in February 2023, for the third year in a row. In March, Cyclone Gabrielle caused a flood emergency that lasted for 177 days in Queensland and NSW before hitting New Zealand’s North Island, Vanuatu, Solomon Islands and Norfolk Island.  

There have also been torrential rains and flooding in central and south-west China and there are flood warnings in place in the north of the country. 

In South Africa, KwaZulu-Natal was flooded in March 2023 and again in June, when 176mm of rain fell in 24 hours. 

Heavy rainfall in a short period leads to flash floods when the water cannot be absorbed by the ground or drained away. Rivers burst their banks and flooded towns and cities in Romania in February. 

Flash floods can also be caused by fast-melting ice sheets or glaciers, as was the case in Pakistan in 

June as Cyclone Biparjoy swept through. World Weather Attribution said the climate crisis may have increased the intensity of rainfall by up to 50%, in relation to a five-day downpour that struck the provinces of Sindh and Balochistan.

Technology to combat flooding

Researchers at the Institute of Geodesy and Geoinformation at the University of Bonn, Germany, have developed a system of sensors, operated with solar cells, which monitor river water levels and transmit data to an evaluation centre using a global navigation satellite system (GNSS) receiver and antenna. The sensors are reliable, cost-effective (around €150) and do not need any maintenance. The receiver and antenna at the heart of the system are also low cost, explains Dr Makan Karegar at the university. 

Signal waves transmitted by satellites are partially picked up directly by the antenna, and the rest are reflected from the surface of the water. The reflection means these signals have a longer path, and when this data is superimposed on the directly received signal, the interference can be used to calculate the distance between the water level and the antenna.

The system has been installed in Wesel in North Rhine-Westphalia. The GNSS antenna can be attached to a bridge, building, tree or fence next to the river, says Karegar. It is able to measure the river level around the clock without any contact and transmits data via a mobile network. It is accurate to within 15mm. While this is less accurate than a radar sensor, it is sufficient for flood alerts and considerably cheaper. It is suitable for rivers at least 40m wide. “This is the smallest radius from which the antenna can receive the reflected satellite signal,” Karegar says. “If the watercourse is too narrow, most of the reflected signals come from the land.”

Heatwaves 

On 3 July 2023, the world’s hottest day was recorded by the NOAA. The average global temperature of 17.01°C exceeded the record of 16.92°C set on 24 July 2022. This follows the eight warmest years on record, even with a cooling La Niña for the past three years, which has acted as a temporary brake on global temperature increase, says the secretary-general of the World Meteorological Organization, Professor Petteri Taalas. 

The world’s average air temperature fluctuates between 12 and 17°C and has averaged 16.2°C at the beginning of July since 1979. Scientists point to a combination of climate change and this year’s El Niño for the increase. 

Beijing recorded its hottest June day since records began, and parts of northern China sweltered in 40-degree heat. In north Africa, there have been temperatures of 50°C, and a heat dome in the southern US has resulted in temperatures breaking 43°C this summer. 

Europe has experienced consecutive heatwaves as anti-cyclone Cerberus sweeps Italy and southern parts of Spain, with temperature highs of 44 to 48°C. The record temperature of 48.8°C was experienced in Floridia, Sicily, in 2021. 

Forest fires

Increasing temperatures make vegetation dry and easy to ignite, whether triggered by electrical storms, careless tourists or acts of arson. 

There have been forest fires this year in Canada’s Northwest Territories following a heatwave when temperatures reached 37.4°C.

There were 420 active forest fires in July across the region, of which 150 are in Quebec. So far this year, 4.4 million hectares have been burned. Forest fires also raged in Thailand, across Khao Nang Dam forest park, north-east of Bangkok, in March.

Chile was subjected to 407 active forest fires that affected 43,000 hectares from 30 January to 20 February this year. 

In 2021, after 10,000 wildfires burned more than four million acres the previous year, California officials began to thin out forests to create fire breaks. Environmental groups protested that native plant species were being destroyed. Energy companies were also urged to maintain power lines and vegetation around them to avoid contact with extremely dry vegetation.

And, at the time of writing, a heatwave across southern Europe and the Mediterranean has resulted in mass evacuations of holiday-makers in Greek islands such as Evia, Rhodes and Corfu, as life-threatening forest fires take hold.

Technology to combat forest fires

An ‘Internet of Trees’ has been developed by Silvanet using solar-powered wildfire sensor nodes with LoRaWAN (long-range wide-area network) technology and machine learning to monitor forest areas and detect wildfires. The sensor nodes are linked to the internet via the Silvanet Border Gateway at the edge of the forest using 4G, 2G or GPRS connectivity.

Drought

El Niño disrupts the usual supply of moisture, causing heavy, prolonged rain in some areas and severe drought in others. 

This year saw the continuation of the longest drought in 40 years in the Horn of Africa, affecting Somalia, Ethiopia and Kenya. The rainy season was the driest the region had seen for 70 years and crops failed again as the Horn saw its sixth failed rainy season. This year also saw Madagascar endure its fourth drought in as many years. Malawai has experienced its second consecutive crop failure this year, and Namibia and Zambia have both seen below average rainfall.

Caroline Hayeshttps://eandt.theiet.org/rss

https://eandt.theiet.org/content/articles/2023/09/extreme-weather-the-technologies-used-to-combat-climate-change/

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