Tropical Cyclone Idai highlights climate change issues

Friday March 22 2019

Cyclone Idai

Zimbabwe President Emmerson Mnangagwa (left) speaks to villagers as he visits Chimanimani, on March 20, 2019, during his tour of areas in Manyikaland devastated by Cyclone Idai. PHOTO | EKESAI NJIKIZANA | AFP 

BBC
By BBC
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As Mozambique and Zimbabwe try to pick themselves up following devastation from Tropical Cyclone Idai, the role of climate change is becoming more and more relevant.

The interesting bit is that it is not apparent that human activities have facilitated the occurrence of such disasters, as researchers pore over.

Oxfam International, for example, observes that though climate disasters ranging from deadly heat waves to hurricanes in various parts of the globe are normal, the resulting devastation is alarming.

"Climate hazards are natural events in weather cycles. We’ve always had hurricanes and droughts, flooding and high winds. However, we are currently witnessing a scale of destruction and devastation that is new and terrifying," it says.

Mozambique cyclone

People take part in looting sacks of Chinese rice printed "China Aid" from a warehouse which is surrounded by water after a cyclone hit Beira, Mozambique, on March 20, 2019. PHOTO | YASUYOSHI CHIBA | AFP

Cyclone Idai is one of the worst cyclones of the Indian Ocean season. And experts predict that as the temperatures keep rising, floods, cyclones and storms will equally rise.

"The interesting thing for the area is that the frequency of tropical cyclones has decreased ever so slightly over the last 70 years. Instead, we are getting a much higher frequency of high-intensity storms," Dr Jennifer Fitchett from the University of the Witwatersrand, in South Africa, said.

IMPACT

So far more than 300 people in the two nations have perished, as survivors battle flash floods.

Mozambican President Filipe Nyusi on Tuesday said: "We already have more than 200 dead, and nearly 350,000 people are at risk. We are in an extremely difficult situation."

And Land and Environmental Minister Celso Correia added that at least 15,000 people are marooned as rescue operations continue.

"Yesterday we had counted 15,000 people that still need rescue today -- 15,000 people who are in bad shape. They are alive, we are communicating with them, delivering food, but we need to rescue them and take them out," he told reporters on Thursday.

Cyclone Idai

Families conduct traditional rituals at the mass grave site of victims of Cyclone Idai that hit Ngangu, a township of Chimanimani, on March 20, 2019. PHOTO | ZINYANGE AUNTONY | AFP

When such disasters take place the impact worsens because of contributing factors like rain.

"There is absolutely no doubt that when there is a tropical cyclone like this, then because of climate change the rainfall intensities are higher. And also because of sea-level rise, the resulting flooding is more intense than it would be without human-induced climate change," Dr Friederike Otto from the Environmental Change Institute, University of Oxford, said.

PAST DISASTERS

A poor country with a long coastline, Mozambique is especially vulnerable to storms sweeping in from the Indian Ocean. More than 700 lives were lost during a devastating flood there nearly 20 years ago.

A huge international response saw the Royal Air Force send six helicopters to rescue survivors. Back then, the priority was to save lives.

Little thought was given to rebuilding homes and infrastructure with new designs to help them withstand future storms.

Development experts have long argued that reconstruction should enshrine the principle of resilience, with roads raised high enough to stay dry in floods and houses made robust enough to resist cyclone-strength winds.

Mozambique

Rebecca Albino (right), a mother of three children, mourns beside the coffin of her husband, Tomas Joaquim Chimukme, during his funeral, following a strong cyclone that hit Beira, Mozambique, on March 20, 2019. PHOTO | YASUYOSHI CHIBA | AFP

There are plenty of examples of how this forward-thinking can help. In low-lying Bangladesh, there are schools built on high ground which can serve as refuges during storms.

EQUATOR

Another significant issue concerns the strength of cyclones, which pulls in the role of global warming.

Dr Fitchett advances that high sea-surface temperatures sit at the centre of high-impact storms. Warmer seas mean there is more energy available for cyclones, which only form when the water reaches 26 degrees Celsius.

But raised temperatures are not the only catalysts; storms also need help from the Earth's rotation to cause them to whirl.

This rotating effect gets stronger the further you move away from the Equator and towards the poles.

"Under increasing sea-surface temperatures, we are seeing the line of constant temperature required for these storms to form moving further and further towards the South Pole. So it is increasing the range in which these storms can form and that's then allowing them to intensify so quickly," Dr Fitchett said.

WARMER SEAS

However, in previous decades, the further away you were from the Equator meant the cooler the seas became, and so any tropical cyclones that formed lacked adequate energy to persist. Now climate change is impacting that relationship.

But warmer temperatures are not always a bad thing; they may also counter the strength of cyclones. "On the one hand, you have the higher ocean temperatures and that lends more energy for tropical cyclones to form. But you also have higher temperatures in the atmosphere which leads to more wind shear, which weakens hurricanes," Dr Otto said.

global warming

Students march to the Museum of Natural History to protest the lack of action on global warming and other climate related issues on March 15, 2019 in New York City. PHOTO | SPENCER PLATT | AFP

According to researchers, about seven different ocean or atmospheric conditions are required for cyclone formation and normally only a couple of these occur.

However, because of climate change, more and more of these conditions are coinciding with each other and that's why these big storms happen very quickly.

VULNERABLE

Whatever arguments about the impacts of climate change on tropical cyclones, the damage caused in Mozambique has much more to do with the vulnerability of people on the ground than rising temperatures.

Tropical cyclone

A picture taken on March 20, 2019 shows the broken part of the building of a logistics company after a strong cyclone hit Beira, Mozambique. PHOTO | YASUYOSHI CHIBA | AFP

The onus is now on governments to push for better disaster management policies. "If you look at North America, they are experiencing Category 5 cyclones quite regularly now, and they don't experience the level of damage that Mozambique is seeing," said Dr Fitchett.

"When a storm like this comes along, the potential for devastation is infinitely higher. A city like Beria is at much higher risk, because not only have you many more people there, it's also so much more difficult for them to get out."