Q&A: Are the 2019-20 locust swarms 

linked to climate change?

DAISY DUNNE 10.03.2020 CARBONBRIEF.ORG

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Q&A: Are the 2019-20 locust swarms linked to climate change?

The past few months have seen locust swarms as large as entire cities sweep across countries in East Africa and surrounding regions.

With each insect able to eat its two-gram body weight in food each day, it is estimated that the swarms of billions are devouring enough crops to threaten the food supply of millions of people.

Though the region has seen locust plagues since biblical times, the scale of the current outbreak is the largest seen in 25 years in Ethiopia and Somalia – and in 70 years in Kenya.

Some media reports have pointed to a possible link between the current outbreak and climate change.

In particular, they have suggested that the plague has been worsened by recent heavy rains and unusual storm activity in the East African region. These impacts are linked to the “Indian Ocean Dipole”, a climate system that affects weather from East Africa to western Australia.

In this Q&A, Carbon Brief speaks to scientists to ask how climate change is affecting the Indian Ocean Dipole, and whether it is the climate or other factors that are behind the current locust outbreak.

Is East Africa’s current locust outbreak unprecedented?
How is the current locust outbreak linked to climate conditions?
Is climate change affecting the Indian Ocean Dipole?
What other factors are playing a role in the locust outbreak?
Will locust outbreaks become more common in East Africa in the future?


Is East Africa’s current locust outbreak unprecedented?

For months, locust plagues stretching tens of kilometres in length and breadth have blighted central and eastern Africa, the Middle East and parts of Asia, including Pakistan and India.

The swarms first arrived in the Horn of Africa at the end of summer 2019. They had moved in from the Arabian desert, where good breeding conditions in the months prior had allowed them to multiply by an astonishing 8,000-fold, according to the UN’s Food and Agricultural Organization (FAO).

In the autumn months of 2019, the insects spread further inland from Somalia and Ethiopia into countries including Kenya and Uganda. In Kenya, the FAO’s locust watch service identified one swarm that was up to 60km long and 40km wide – roughly the size of Luxembourg. The swarm was made up of up to 20bn individual locusts, officials said

A desert locust swarm in northeastern Kenya. Credit: FAO/Sven Torfinn

At the same time, locusts moved from the Arabian desert into Middle Eastern countries, such as Iran, Bahrain and Kuwait, and into parts of Asia, such as India and Pakistan.

By January and February of this year, the locusts had moved into Eritrea and threatened to spread further to Sudan, parts of the Democratic Republic of the Congo and Tanzania. China has also begun to brace itself for a possible outbreak.The impact of the locust invasion around Shilabo, Ogaden, Somali region in Ethiopia. Credit: FAO/Petterik Wiggers

They have devoured hundreds of kilometres of crops across East Africa, including in the Rift Valley. This could have particularly “severe consequences”, the FAO says, given the region is home to almost 12 million food-insecure people.

In Ethiopia, the swarms also caused a plane to veer off course after insects slammed into its nose, engine and windshields.

In its latest update on 2 March, the FAO’s locust watch service said the threat from locusts currently remains high in East Africa, parts of the Middle East and Pakistan.

It also warned of large increases in locust numbers in the coming months. Parts of East Africa including Kenya and Somalia could see 400-fold increases in swarm sizes by June as the insects reproduce once again.

The map below, provided by the FAO locust service, shows where insect numbers are likely to increase between March and June.

Forecast for locust swarm spread from March to June 2020. Credit: FAO Locust Watch

(UPDATE: On 14 April, the FAO Locust Watch released a further statement saying that “widespread rains…in late March are expected to cause a dramatic increase in locust numbers in East Africa, eastern Yemen and southern Iran in the coming months”. Efforts to control locust numbers have been hampered by the coronavirus outbreak, which is causing delays to pesticide deliveries across country borders, Kenyan officials told the Guardian.)

(UPDATE: The locust swarms moved further into western India from Pakistan and Iran around mid-May, according to an FAO Locust Watch update. The outbreaks in India are the worst seen in the country for 25 years, reports the New York Times.)

The FAO has estimated that the current outbreak is the largest seen in 70 years in Kenya and in 25 years in Somalia and Ethiopia. Pakistan officials say the outbreak there is the worst in 30 years.

Yearly records on the number and size locust outbreaks are not readily available for countries in East Africa, Keith Cressman, a senior locust forecasting officer at the FAO, tells Carbon Brief. This makes it difficult to establish if the current outbreak in East Africa is truly unprecedented.

The FAO does keep data on the number of countries reporting locust swarms each year globally. This is shown on the chart below, which includes the number of countries reporting locust plague “onset” (black), “peak” (purple) and “decline” (pink) from 1900-2019.

Countries report a plague “onset” when locusts are beginning to breed, plague “peak” when they have experienced heavy and widespread outbreaks for more than a year and plague decline when numbers begin to fall again, according to the FAO.

(The chart also shows the number of countries each year reporting locusts at low densities in yellow.) The number of countries reporting locust plague “onset” (black), “peak” (purple) and “decline” (pink) from 1900-2019. Chart also shows the number of countries reporting locusts at low density (yellow). Data source: FAO. Chart by Carbon Brief using Highcharts.

This chart shows that 2019 was not a record-breaking year for locust outbreaks worldwide – and that the world saw much larger plagues in the 20th century than in recent times.

However, it is worth noting that the factors driving locust swarms are largely regional – and global trends in locust outbreaks would, therefore, not be expected, scientists tell Carbon Brief. (The factors driving locust swarms are discussed in more detail below.)


How is the current locust outbreak linked to climate conditions?

Some media reports have pointed to a link between the current outbreak and unusual storm and rainfall activity around East Africa.

To understand how the cyclones and the outbreak are linked, there is a need to first understand desert-locust biology, explains Dr Philipp Lehmann, a researcher of insects and the environment from Stockholm University.

Desert locusts are “biphasic” animals, meaning they can take on two entirely different forms, says Lehmann. In their “solitary” form, they are drab brown in colour and relatively harmless to crops. But, under certain conditions, the insects can switch into a “gregarious form” – turning electric yellow and displaying swarming behaviour. Left image: Desert locust. Credit: Itsik Marom / Alamy Stock Photo.
Right image: Desert locust. Credit: FAO/Sven Torfinn.

The Arabian Peninsula – the land mass between East Africa and Asia comprising Saudi Arabia, Yemen, Oman, Kuwait, Qatar, Bahrain and the United Arab Emirates – was struck by several unusually severe cyclones between 2018 and 2019.

When the first storm – Cyclone Mekunu – hit the Arab peninsula in May 2018, it filled a vast desert near Yemen and Oman, known as the Empty Quarter, with freshwater lakes.

The moisture caused lush vegetation to grow in the usually barren environment, attracting desert locusts hunting for food into the area, Lehmann tells Carbon Brief. “The first cyclone lead to this emergence of optimal breeding grounds for the locusts.”

Desert locusts only switch to a gregarious form when they reach high enough numbers in a certain area, explains Dr Cyril Piou, a locusts researcher at France’s Agricultural Research for Development Centre (CIRAD). He tells Carbon Brief:

“Once they reach a certain density, they start to touch each other a lot and this triggers them to change their behaviour.”

Satellite image of Cyclone Luban close to the Arab peninsula on 11 October, 2018. Credit: NASA Earth Observatory/Lauren Dauphin

By the time that the second storm – Cyclone Luban – arrived in the same region in October, the locusts had just hit a critical point where they had started to multiply rapidly, says Lehmann:

“It was actually the second cyclone that was the big problem because the locusts were at a point where they had the ability optimise their reproductive capacity to produce a new front of migrating locusts.”

Spurred on by the ample food supply provided by the cyclones’ rains, the locusts multiplied rapidly – increasing their numbers 8,000-fold in just a few months.

The unusually rainy period was then followed by a particularly mild winter, which allowed the locusts to survive in large numbers, says Lehmann.





Then, in the summer of 2019, the insects began to migrate from the Arab peninsula into the horn of Africa.

As the insects moved through East Africa, the region was hit by unusually wet conditions and more cyclones – allowing the swarms to grow even larger, says Lehmann.

Across the Horn of Africa, rainfall between October and mid-November was 300% above average. In Kenya, rainfall was up to 400% higher than average. Overall, the Horn of Africa was hit by eight cyclones in 2019, the largest number in any year since 1976.

As well as providing the conditions needed for vegetation growth, cyclones could also worsen outbreaks by providing winds for the locusts to hitch a ride on, says Lehmann:

“Winds can definitely push insects in great numbers over great distances – and at quite a small energetic cost, meaning that they have more energy available for reproduction.”

The unusual wet weather in East Africa is linked to a wider climate system known as the Indian Ocean Dipole (IOD). The dipole affects weather on both sides of the ocean, from East Africa and the Arab Peninsula to Indonesia, Papua New Guinea and Australia. (The IOD also sometimes referred to as the “Indian Niño” because of its similarities to El Niño in the Pacific.)

The dipole, which was formally identified in 1999, has three phases – positive, negative and neutral. Events typically develop in the northern hemisphere summer, peak in the autumn and then decline rapidly in winter. However, events can also stay put for extended periods. 

In a neutral dipole phase, waters around Indonesia, Papua New Guinea and Australia are warm, which causes air to rise up and fall as rain. Winds blow in a westerly direction. In this phase, the dipole has very little effect on temperatures in countries surrounding the Indian Ocean. The diagram below illustrates what occurs in a neutral phase.Diagram showing the impacts of a neutral Indian Ocean Dipole phase. Credit: NOAA

During a positive phase, however, this pattern reverses. Westerly winds weaken and, sometimes, easterly winds form – dragging warm water towards the Arab Peninsula and the Horn of Africa.

This, in turn, plays a role in driving cyclones and heavy rainfall in the region. Cyclone frequency increases during a positive dipole phase because the additional warmth and moisture brought by the climate system acts as fuel for budding storms. The diagram below illustrates the impacts of a positive IOD phase.Diagram showing the impacts of a positive Indian Ocean Dipole phase. Credit: NOAA

The IOD was in positive phase in the June to December period of both 2018 and 2019. In 2019, the dipole reached its most extreme positive level in 40 years.

As well as driving rains in East Africa, the strongly positive dipole also played a role in driving Australia’s unprecedented 2019-2020 bushfires. This is because rains shifted towards East Africa, leaving Australia with drought-like conditions.

(A recent analysis by the World Weather Attribution initiative found the conditions for fire in Australia were made “much more severe” by the positive dipole phase.)


Is climate change affecting the Indian Ocean Dipole?

Some people have suggested that the extreme wet weather seen during the 2018 and 2019 dipoles could be linked to climate change.

António Guterres, the UN’s secretary general, recently said in a statement:


“There is a link between climate change and the unprecedented locust crisis plaguing Ethiopia and East Africa. Warmer seas mean more cyclones generating the perfect breeding ground for locusts. This is getting worse by the day.”

The extreme positive dipole in 2019 certainly does fit into a picture of long-term change, says Dr Wenju Cai, director of the Centre for Southern Hemisphere Oceans Research at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia. He tells Carbon Brief:


“It’s highly likely that the event that we’ve just seen has a very strong warming component in it – but attributing individual events to long-term climate change is not a simple issue.”

To understand how the dipole is changing, scientists study something known as the “dipole mode index” – which is the difference between average sea-surface temperatures in the western Indian Ocean and the eastern Indian Ocean, explains Cai.

During a positive phase, temperatures in the western Indian Ocean are higher than in the eastern Indian Ocean – giving an overall positive index. The chart below shows how the monthly dipole mode index changed from January 1979 to December 2019.Monthly Indian Ocean Dipole mode index from January 1979 to December 2019. Credit: NOAA

The chart shows how the mode index reached its highest recorded level in the northern hemisphere winter of 2019, the time when East Africa was hit by heavy rains and unusual cyclone activity.

The dipole was also positive in 2018, when the Arab peninsula was struck by several cyclones – though this dipole was less extreme, Cai says.

Looking back over longer timescales, it is clear that the dipole mode index has been “rising up steadily”, he adds:


“There is always a role for natural variability, but we think this is due, in a large part, to climate change because this persistent trend of 60-70 years is not fully consistent with, for example, decadal variability, which would have gone up and down over a 70-year period.”

A 2009 study led by Cai found that positive phases of the dipole have increased in frequency since the 20th century. In the early 20th century, a positive dipole phase occurred roughly four times in a 30-year period. However, in the 30-year period spanning 1989-2009, there were 10 positive dipoles.

A study published this week in Nature reinforced the finding that positive dipole events are becoming more frequent. It looked at ancient coral records stretching back to 1240 and found that positive dipole events that were once rare in the ancient world and now commonplace.

Climate change could be skewing the dipole in favour of positive phases because the western Indian Ocean – near Africa – is warming at a faster rate than the eastern Indian Ocean, Cai explains:


“With the western Indian Ocean warming faster, it’s easier for the temperature difference between the west and the east to become very large. And, so, it’s much easier to have the rising air that brings rain happening in the western part of the Indian Ocean.”

Further analysis by Cai and colleagues found that uncontrolled future climate change could cause positive dipole events to increase by a factor of three by 2099, when compared to the period 1900-1999.

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Even if global temperature rise is limited to 1.5C – the aspirational target set by the Paris Agreement – the number of positive dipole events could double, when compared to the pre-industrial era, according to another study.

Such increases are likely to bring about more frequent and intense cyclones, says Dr Agus Sontoso, a senior research associate at the Climate Change Research Centre at the University of New South Wales in Sydney. He tells Carbon Brief:


“The Indian Ocean itself is warming everywhere. So it’s reasonable to think that under climate change, we expect to see more frequent, if not stronger, cyclones in the region.”


What other factors are playing a role in the current locust outbreak?

Though the rainy weather played a role in driving the current locust outbreak, there are several factors that could have contributed to the insects’ spread, scientists tell Carbon Brief.

One major factor is that countries did not act quickly enough to prevent the locusts from spreading in 2018, says Piou:


“This specific crisis is also due to the fact there was no preventative management in many of the places where the rain fell. Saying it’s directly linked to climate change is too simple – it’s forgetting that we should have been preventing the outbreak in the first place.”

According to the FAO, the best way to stop locusts from spreading is to spray small concentrated areas with pesticides. This is most effective early on in an outbreak, when the insects are still multiplying, says Piou.

A government staff member of the Ethiopian ministry of Agriculture spraying against locusts in the Somali region of Ethiopia. Credit: FAO/Petterik Wiggers

The responsibility of controlling locust numbers falls to national governments – with international organisations stepping in during outbreak and crisis situations.

The insects first started to multiply in the south of the Arab peninsula, a region experiencing political instability and conflict. This may have thwarted early detection and prevention methods, says Lehmann:


“There’s actually some studies on this – though not in an African context. I’ve worked a lot with the Colorado potato beetle, which arrived in Europe during the first world war. Before the war, it was contained by early prevention efforts. During the first world war, people had other things on their mind – the potato beetle arrived, established itself and started spreading. Then, during the interwar period of the 20s and 30s, the spread was quite contained. But during the second world war, there was the biggest spread that we’ve ever seen.”

It is worth noting that other parts of Africa, including Niger and Mauritania, periodically experience heavy rains, but do not see outbreaks on the same scale, says Piou:


“The prevention system is working in some other parts of the world. For example, in western Africa, they experience heavy rains that arrive and create some good conditions for the desert locust to breed and multiply – but they don’t see such large outbreaks.”

Another possible driver influencing the current outbreak could be an increase in irrigated agriculture in parts of East Africa, says Lehmann:


“People live year-round in these semi-arid areas and you need irrigation in order to maintain crops. This also creates stopping points for a swarm.”

Overall, it is likely that several factors worked in tandem to make the current outbreak so extreme, says Lehmann:


“I think there can be several reasons for why an outbreak starts and, in many ways, it’s like the stars have to align – and, when they do, something very bad happens.”


Will locust outbreaks become more common in East Africa in the future?

Though studies suggest that the wet conditions seen in Africa during the winter 2019 are likely to become more frequent with climate change, it is less clear if there will be a corresponding increase in locust outbreaks, scientists tell Carbon Brief.

This is because many factors influence the chance of an outbreak, including human factors such as taking early preventative measures, says Piou:


“If there are more cyclones in the Arab peninsula, then eventually, yes, there could be more outbreaks. But still, in any case, the main message should be to be prepared for that with a preventative system.”

It is likely that locust outbreaks will “stay bad” in East Africa, says Lehmann:


“I think they will stay bad – as they are. I base this simply on the fact that locusts are cyclic and there have been outbreaks for thousands of years. If they return, I think there can be several reasons for why an outbreak starts.”

The “jury is still out” on how future temperature rise in the East African region could affect outbreaks, he adds.

(According to Carbon Brief analysis, temperatures around the horn of Africa could increase 1.6-4.6C by 2100, depending on the rate of future greenhouse gas emissions.)

Research suggests that desert locusts do prefer hotter temperatures, says Piou:


“The perfect temperature for a desert locust to multiply is around 35C during the day. And even below this temperature, they display warming up behaviours to reach a body temperature of 40C, which is the optimal temperature for their metabolism.”

However, despite hotter temperatures giving the insects a physiological advantage, it is not yet clear if this would influence their swarming behaviour, says Lehmann.

Overall, climate change is expected to make weather conditions in East Africa less predictable – which is likely to benefit insect pests, he adds:

“I don’t know if it’s the locusts, per se, or some other pests that will respond – but insect pests generally thrive in unpredictable environments.”

Locust plagues point to grim future of climate change
Climatic changes in China, the Middle East and Africa could see more severe outbreaks of locusts devastating food crops

Locusts swarm in the Israeli village of Kmehin. Photograph: Menahem Kahana/AFP/Getty Images

By Ido Liven for ChinaDialogue, part of the Guardian Environment Network

Thu 23 May 2013 

The desert locust, the most notorious of about a dozen locust species for its ability to rapidly multiply and travel long distances, threatens an area of 32 million square kilometres, stretching across 50 countries from west Africa to India.

The fearsome insect has been farmers' foe since the earliest days of agriculture.

When solitary, locusts are harmless. But when they congregate into groups they transform – in behaviour and even appearance – into killer vegetarians. In turn, swarms can be as large as several hundred square kilometres, of which a single square kilometre can comprise at least 40 million bugs, at times even double that.

In the immature adult phase, a locust can consume its own weight – about two grams – in vegetation per day, according to the UN's Food and Agriculture Organization (FAO). One tonne of desert locusts ("a very small part of an average swarm", according to FAO's website) could guzzle in a single day an amount of food equivalent to that consumed by 2,500 people. Locust plagues could therefore seriously imperil crop production, and in turn food security.

An ongoing desert locust upsurge, primarily along the Red Sea periphery, possibly acts as a reminder to a natural threat that is often overlooked, or even deemed a thing of the past.

Swarms of locusts spread from North Africa

Countries today are considerably better equipped to deal with the threat than they used to be. The second half of the twentieth century has seen a dramatic decline in frequency, duration and intensity of desert locust plagues, largely thanks to improved control and monitoring capacities in the affected countries.

"What we have done as a big improvement is to be able to monitor where the locust are and try to control them," says Pietro Ceccato, an environmental remote sensing expert with the International Research Institute for Climate and Society (IRI) at Columbia University. "Now we have that information – both from the control teams and from the satellite. We know where to target the control."

And yet, in anticipating future locust invasions, climate change appears to be one key unknown.

"This year is a bit unusual," says Keith Cressman, senior locust forecasting officer at FAO. Normally, he explains, after a good breeding season like this year's, the locusts would move from Sudan to the interior of the Arabian Peninsula, across the Red Sea. This autumn, however, while some did reach Saudi Arabia, groups started migrating northwards to the interior of Sudan and further to Egypt, not before Sudanese authorities treated close to 270 square kilometres.

By late February, an outbreak looked imminent, as groups and swarms of a new locust generation started moving north. In early March, Egyptian news outlets and social media were teeming with reports and photos of the clouds of locust that had descended on Cairo.

"It is relatively rare that Desert Locust swarms reach Cairo," the website of FAO's locust unit later reported. "This last occurred in November 2004, almost 50 years to the day after the previous occasion."

Within days, the swarms flying further east crossed the border into Israel, reaching the north west of the Negev desert. Three weeks later Jewish Israelis were celebrating Passover, commemorating the exodus of the Israelites from ancient Egypt, preceded by the Ten Plagues, the eight of which was the Plague of Locust.

According to FAO's Locust Watch, April has seen a total of 220 square kilometres treated across five countries, down from 790 square kilometres in March.

In Israel, the ministry of agriculture reported in mid-May that damages to crops were "minimal," but concerns are of the next waves of locust coming in from Egypt's Sinai peninsula as well as a new generation of the pest after extensive hatching has been detected.

"[Israeli] researchers had said that [the locusts] would not even be able to breed here due to weather conditions. And not only did they manage to breed, they have bred excellently and even settled. So, all projections were disproved," Dafna Yurista, the ministry's spokesperson told chinadialogue. According to FAO, the last time Israel saw locust breeding and formation of hopper bands was in April 1961.

Nevertheless, and despite the ongoing outbreak, control operations across the region appear to have been effective. "So far, there hasn't been any significant damage to crops," says FAO's Cressman.

In Locust Watch's latest update, from May 15, three countries were put on the second highest level of alert – Saudi Arabia, Israel and Sudan – and control teams have been operating to curb the infestations before the young hoppers become voracious adults by the end of the month.

Adult locust groups forming in these countries are expected to move back to the summer breeding areas in central Sudan. In addition, some locusts now in Saudi Arabia, the Locust Watch update stated, "could reach southwest Iran and continue moving eastwards."

"So far," Cressman says, "Sudan, Egypt, Saudi Arabia have been lucky. What we're concerned about now is this coming month in Sudan, where we have a new generation of locust, and those immature adults more likely to stay in those cropping areas and eat whatever is green – basically, the seasonal crops."

The last time the region had faced a large-scale locust upsurge was in 2003-2005. Back then, swarms took off from Niger and moved up to north Africa, before heading east along the Mediterranean coast. Overall, 26 countries were affected, and nearly 130,000 square kilometres were treated.

Back then, Morocco alone treated 40,000 square kilometres over a two-year period, escaping the plague without any substantial damage, says FAO's locust expert in the country Said Ghaout. This time, Morocco has seen a considerably smaller extent of infestation.

The impact of climate change

Yet both outbreaks have shown anomalous patterns, mostly owing to unusually favorable weather conditions at the locusts' breeding areas. Ghaout does not rule out the possibility that climate change played a role, or that these outbreaks might be a sign of things to come. "This is a question everybody is asking," he says.

"It's a real difficult topic," says Cressman about the possible effect of climate change on the desert locust. Generally, global meteorological models aren't sufficiently reliable to make concrete predictions for the desert locust habitat range, and regional models for the relevant desert areas are not developed enough, he says.

Overall, forecasts for desert locust activity rely on four main factors: temperature, rainfall, vegetation and wind. "I took a look at all the data that we have so far, and looked at temperature – because that's what everyone kind of agrees on, and we have the most data on – and it seems like if there's an increase of temperature under climate change scenarios, the effect on desert locust is very minimal," says Cressman. In this case, "they might be able to get an extra generation of breeding in before the habitat becomes unfavorable."

It's not all about temperature, however. To breed, desert locusts require moist soil and vegetation, so precipitation is key. But climate change models for the region contradict one another when it comes to rainfall, says Cressman.

For instance, in late April and early May, Saudi Arabia saw more rainfall than usual, which could in turn contribute to locusts moving further into the interior of the Arabian peninsula. "It happens that sometimes you have more rain, sometimes you have less rain," says IRI's Ceccato, who monitors climatic and ecological conditions that affect desert locust activity. "But that happens. It's variability. To relate that to climate change, it's difficult."

China's locust plagues

Several studies have tried to explore the possible impact of climate change on the abundance of another species, the Oriental migratory locust, in China. In 2011, researchers examined locust outbreaks recorded over a period of 1,910 years and meteorological data over the same time-span and concluded, that "there were more locusts under dry and cold conditions and when abundance was high in the preceding year or decade." Therefore, an increase in temperature or rainfall would actually mean fewer locust outbreaks.

A paper published four years earlier, based on a thousand years of records, has also suggested that warming could mean fewer locust plagues in China, since locust numbers were historically "highest during cold and wet periods".

Yet, a 2009 study using the same data came to different conclusions. Climate change, these authors said, could worsen locust outbreaks in China. Taking a more geographically nuanced approach, the researchers showed that, in north China, the most severe locust upsurges happened in warm and dry years. In south China, however, it was during warm and wet years.

Despite their contradictions, taken together these studies and others do offer some valuable insights, and not only for China. First, scientists seem to agree that rainfall could be affecting locust dynamics more than temperature. There also appears to be a consensus that climate change predictions for rainfall patterns are so far unsatisfactory.

And this is not the only missing variable. "The other aspect that nobody is really looking at yet is what's going to happen to the wind under climate change," Cressman says, "because of course locusts migrate with the wind."

Even if projections are still inconclusive, history tells us that locusts have braved previous climatic changes, and humans need to prepare.

"Probably all countries need to review their preparedness in terms of some of these climate change scenarios, and maybe look at the worst case scenario," says FAO's Cressman. In particular, that means preparing for longer locust seasons, he explains. "They're going to have to make those plans a little more flexible."

Topics
Insects
Guardian Environment Network

DIAMOND PRINCESS VIRUS

Superspreader Events Played a Key Role in Igniting The Current Pandemic Globally

The Diamond Princess cruise ship was a superspreader site. 

(Alpsdake/Wikimedia Commons/CC BY 4.0)

KELLY MACNAMARA, AFP
21 NOVEMBER 2020

At churches, on cruise ships, and even in the White House, superspreading events that can sicken dozens, even hundreds, of people have illustrated the potential for the coronavirus to infect in dramatic bursts.​

Experts say these large clusters are more than just extreme outliers, but rather the pandemic's likely main engine of transmission.

And understanding where, when, and why they happen could help us tame the spread of the virus in the period before a vaccine may be widely available.

Research increasingly suggests that the coronavirus SARS-CoV-2 does not fan out evenly across the population, but spreads at the extremes in an almost "all or nothing" pattern.

Many studies now suggest the majority of people with COVID-19 barely pass it on to anyone else, but when infections happen, they can be explosive and supercharge an outbreak.

Then the virus can infect "10, 20, 50, or even more people", said Benjamin Althouse, research scientist at the Institute for Disease Modeling.

This corresponds to the "80/20 rule" of epidemiology, where 80 percent of cases come from only 20 percent of those infected, but Althouse said this coronavirus may be even more extreme, with 90 percent of cases coming from potentially just 10 percent of carriers.

This transmission pattern is like "throwing matches on a pile of kindling", he told AFP.

"You throw one match, it doesn't ignite. You throw another match, it doesn't ignite. You throw yet another match, and this time you see flames blaze up," he said.​

"For SARS-CoV-2, this means that while it is difficult to establish in new places, once established, it can spread rapidly and far."
Virus 'hallmark'

Superspreading events have grabbed headlines, looming large in the narrative of the unfolding pandemic.​

In February, the Diamond Princess and its 4,000 passengers spent weeks in quarantine at port in Japan as the number of infections on board climbed, reaching 700.​

The same month a 61-year-old woman, known as "Patient 31", attended several church services of the Shincheonji Church of Jesus in the South Korean city of Daegu.​

The Korea Centers for Disease Control and Prevention has since linked more than 5,000 infections to Shincheonji.

More recently the virus managed to infiltrate the White House despite a host of measures to keep it out.

Political gatherings, business conferences, and sports tournaments have all acted as infection incubators, but these high profile events could just be the tip of the iceberg.

A study by US researchers, based on one of the world's largest contact tracing operations and published in Science in September, found that "superspreading predominated" in transmission.

Analysing data from the first four months of the pandemic in the states of Tamil Nadu and Andhra Pradesh in India, the authors found that just eight percent of infected individuals accounted for 60 percent of new cases, while 71 percent of people with the virus did not pass it on to any of their contacts.

Perhaps this should not be a surprise.

Maria Van Kerkhove, an infectious disease epidemiologist at the heart of the World Health Organization's pandemic response, tweeted in October that "superspreading is a hallmark" of coronaviruses.

Indeed, it has been observed in many infectious diseases.

One of the most famous superspreaders was Mary Mallon, a cook working in New York in the early 1900s who was the first documented healthy carrier of typhoid bacteria in the US.

Blamed for giving the illness to dozens of people, she was given the unsympathetic label "Typhoid Mary" and forcibly confined for years.

Measles, smallpox and Ebola also see clustering patterns, as did the other coronaviruses, SARS and MERS.

K factor

Early in the pandemic, much attention was focused on the basic reproduction number (R0) of SARS-CoV-2.

This helps calculate the speed a disease can spread by looking at the average number of others a person with the virus infects.

But looking at transmission through this metric alone often "fails to tell the whole story", said Althouse, who co-authored a paper on the limitations of R0 in the Journal of the Royal Society Interface this month.

For instance, he said Ebola, SARS-CoV-2, and influenza, all have an R0 value of around two to three.

But while people with the flu tend to infect two or three others "consistently", the transmission pattern for those with Ebola and SARS-CoV-2 is overdispersed, meaning most will hardly spread it and some will give rise to tens of other cases.

A different metric – "k" – is used to capture this clustering behaviour, although it usually requires "more detailed data and methodology", said Akira Endo, a research student at the London School of Hygiene and Tropical Medicine.

His modelling from the early international spread of the virus, published in Wellcome Open Research, suggested SARS-CoV-2 could be highly overdispersed.

A telltale clue, he said, was that some countries reported numerous imported cases but no signs of sustained transmission – like the match analogy – while others reported large local outbreaks with only a few imported cases.

But even k may not give the full picture, said Felix Wong, a postdoctoral fellow at the Massachusetts Institute of Technology.

His research analysing known COVID-19 superspreading events, published this month in the journal PNAS, found that they were happening even more frequently than predicted by traditional epidemiological models.

They are "extreme, yet probable occurrences", Wong told AFP.
Biology vs opportunity

So why does superspreading occur?

We don't know definitively whether biological factors, such as viral load, play much of a role.

But what we do know is people can spread SARS-CoV-2 without symptoms and given a poorly-ventilated, crowded space – particularly where people talk, shout, or sing – the virus can run rampant.​

This could be why a study in Nature this month found that restaurants, gyms, and cafes account for most COVID-19 infections in the United States.​

Using the mobile phone data of 98 million people, researchers found about 10 percent of venues accounted for over 80 percent of cases.

Given this, experts say the focus should be on these types of spaces – and reducing opportunities for the virus to access large numbers of people.

Wong said his modelling showed that if each individual was limited to ten transmissible contacts, "viral transmission would quickly die down".
Tracking back

Overdispersed spread also means that most people testing positive for the virus are likely to be part of a cluster.

This opens up another way to trace infections: backwards.​

"The idea being that it could be more efficient to trace back, and isolate, superspreaders than it is to trace downstream and isolate individuals who, even if they were infected, might transmit the virus to very few people," said Wong.

Both Japan and South Korea have used backwards contact tracing, which has been credited with helping them curb their epidemics, along with other control measures.

Masks, social distancing and reducing contacts are all ways to limit transmission opportunities, Althouse said, adding that even characterising people as "superspreaders" is misleading.

"There are vast differences in biology between individuals – I may have a million times more virus in my nose than you – but if I am a recluse, I can infect no one," he said.

© Agence France-Presse

Donald Trump Skips G20 Coronavirus Meeting To Play Golf

JAKE MASSEY
Last updated 9Sunday 22 November 2020
Donald Trump skipped a G20 coronavirus meeting to play golf.

Trump skipped the Pandemic Preparedness meeting to play golf. Credit: PA

The outgoing POTUS joined other world leaders for the summit via video-link from The White House yesterday (Saturday); however, shortly after opening remarks began at 8am, he began tweeting about his continuing efforts to overturn the result of the election.

By 10am, he was on his way to the golf course, according to CNN, meaning he missed a 'Pandemic Preparedness' meeting.

The meeting featured remarks from French president, Emmanuel Macron, and the South Korean president, Moon Jae-in, and was focused on the 'coordinated response to the coronavirus pandemic and improved global pandemic preparedness'.

However, Trump made it clear that he did not consider this a final farewell before heading off to play golf.

According to audio obtained by the Observer, Trump said: "It's been a great honour to work with you, and I look forward to working with you again for a long time."

Trump repeatedly criticised his predecessor Barack Obama for playing golf during his administration:

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However, according to CBS News' White House correspondent Mark Knoller, Trump has played golf 298 times during his presidency.

By contrast, Obama played golf 113 times during his first term, according to The Loop.

Meanwhile, the USA recorded a record number of daily Covid-19 cases on Saturday, with 195,500 reported in a 24-hour period, according to John Hopkins.

The country's coronavirus death toll stands at 255,900.

Featured Image Credit: PA

Split-screen: Biden preps to be president, Trump fights for the job he is ignoring

President-elect Joe Biden meets with Vice President-elect Kamala Harris, Senate Minority Leader Charles E. Schumer (D-N.Y.) and House Speaker Nancy Pelosi (D-San Francisco) on Friday in Wilmington, Del.
(Associated Press)

By JANET HOOK STAFF WRITER LA TIMES
NOV. 22, 2020

WASHINGTON — 

Joe Biden’s first two weeks as president-elect have been a throwback to days of yore, when presidents were, well, presidential — one of the many norms that Donald Trump busted during his years in the White House.

Since being declared the election winner, Biden has consulted national security and health experts. He’s had somber chats with world leaders. He’s convened groups of governors, congressional leaders, labor and business bigwigs. He has listened via videoconference to healthcare workers describing their coping with the COVID-19 pandemic, even shedding a public tear with one.

Meanwhile, President Trump has refused to concede and taken ever more brazen steps, legally and politically, to reverse his election defeat. Yet he’s shown little sign of performing the job he’s trying so hard to keep. On Saturday, Trump left the virtual G-20 summit to play golf as other leaders, including those of Germany, France, South Korea and Italy, discussed by video a global response to the worsening pandemic.

The result is a vivid split-screen view of the presidency: While Trump puts governing responsibilities on the back burner to mount his all but doomed rearguard action to hold power, Biden is modeling the role of president as he builds his administration-in-waiting.
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He has responded to Trump’s intransigence by expressing supreme confidence in his own status as president-elect, following the advice of former First Lady Michelle Obama: When they go low, we go high.

Some Democrats wonder whether Biden needs to make a more forceful response to Trump for what amounts to an attack on democracy. He has called the president’s actions “embarrassing” to Trump and the nation, but, for now, Biden has left the most pointed takedowns of Trump’s maneuvering to aides and allies. “It’s absolutely appalling … it’s also pathetic,” said Biden legal advisor Bob Bauer.


POLITICS
Transition tensions escalate as Trump steps up desperate effort to hold on to power

Nov. 19, 2020

Biden’s strategy has been to focus, with increasing urgency, on the public health and national security risks of Trump’s failure to cooperate in easing the transition and denying Biden’s team access to federal agencies’ data and resources. The president-elect is betting that his election mandate is to keep his cool and be the adult in the room.

“Biden got hired because the public wanted something like this,” said former Democratic Party Chairman Howard Dean. “They didn’t want four more years of reality TV and Sturm und Drang.”

Biden’s determination to not fly off the handle is visible every time reporters ask him about Trump’s attacks on the legitimacy of the election result.

He pauses to compose himself, shakes his head a bit and says something like, “Let me choose my words.” It is a marked contrast to Biden’s impassioned critiques of Trump during the campaign.

Now his demeanor sends the clear message: The campaign is over.

Jill Alper, a Michigan-based Democratic strategist who is a veteran of past presidential campaigns, called the Biden transition team’s approach to Trump “pitch perfect.”

“It reminds me of a lesson in Sun Tzu’s ‘Art of War’: ‘The supreme art of war is to subdue the enemy without fighting.’ And there is no need to fight,” she said. “The best thing Biden can do is move quickly to assemble his team, end the pandemic and build back the economy. And that’s what he’s doing.”

Biden’s strategy mirrors his campaign’s in one important respect: Just about everything he does is intended to draw a contrast with Trump.

“You’ve seen, over the last several days, Donald Trump holed up in the White House consulting with people like Rudy Giuliani and ... hatching conspiracy theories about Venezuela and China,” Bauer said. “And you’ve seen President-elect Biden meeting on a bipartisan basis with governors, addressing the public health emergency, and acting like the president-elect he is and the president that he soon will be.”

Biden has been especially visible during this interregnum, holding some kind of public event or announcing senior staff appointments almost every day. Trump, meanwhile, has all but disappeared from the public stage.

Friday, when he announced a policy to reduce the cost of prescription drugs from the White House briefing room, it was only his third public appearance since election night.

“Biden is playing the role of reassurer-in-chief,” said Paul Light, a New York University professor who is an expert on presidential transitions. “He has to be out there, and the transition has to get underway, to reassure people that somebody is at home. Trump has virtually disappeared.”

Americans are giving Biden good marks. A poll released Friday by the nonpartisan Pew Research Center found that 62% of voters rated Biden’s postelection conduct good or excellent, double the percentage who said the same about Trump.

Biden’s transition is a down payment toward fulfilling his campaign promise to restore stability to government after Trump’s tumultuous reign.

Prizing both personal loyalty and competence, Biden is assembling a White House staff packed with longtime confidants and experienced Washington hands. Ron Klain, who will be his chief of staff, has a history with Biden and the Democratic establishment that reaches back to the 1980s; so do top advisors Steve Ricchetti and Mike Donilon.

He’s promised racial and gender diversity. Biden picked former campaign manager Jen O’Malley Dillon as deputy chief of staff, while Rep. Cedric L. Richmond, an African American from Louisiana who was Biden’s campaign co-chair, will be a senior advisor in charge of public outreach, and Julie Rodriguez, Biden’s deputy campaign manager, his director of intergovernmental affairs.

He’s made gestures to some of his former Democratic rivals, placing former campaign aides to Massachusetts Sen. Elizabeth Warren and former Mayor Pete Buttigieg of South Bend, Ind., on the White House communications staff.

One complication: Biden was supported not just by voters craving normalcy but by progressives who want far-reaching change in economic and social policies.

That wing of the party is watching carefully as he builds his Cabinet, and is pushing him to reach beyond establishment regulars to give the left a strong voice.

Many dreamed of seeing Warren in a top post such as Treasury secretary, but that seems unlikely — if only because of the political risk of removing her from the narrowly divided Senate when Massachusetts’ Republican governor would name a replacement.

Sen. Bernie Sanders (I-Vt.), the last primary rival to be vanquished by Biden, is being promoted — by progressives and himself — for Labor secretary.

“It seems to me pretty clear that progressive views need to be expressed within a Biden administration,” Sanders said in an interview with the Associated Press. “It would be, for example, enormously insulting if Biden put together a ‘team of rivals’ — and there’s some discussion that that’s what he intends to do — which might include Republicans and conservative Democrats, but which ignored the progressive community. I think that would be very, very unfortunate.”

Some progressives have already sniped about a few of Biden’s early picks for his staff and transition team. The Sunrise Movement, a group of young environmental activists, called it a “betrayal” of Biden’s commitment to combat climate change that he tapped Richmond, who has received large political donations from the oil and gas industry — hardly a surprise given that it is a major employer in his House district.

Demand Justice and other groups on the left have complained that Biden’s transition advisors include many with corporate ties.

Progressives have mounted campaigns to discourage Biden from offering Cabinet posts to people including Rahm Emanuel, a former advisor to President Obama whom they consider too moderate and criticize for his handling, as Chicago mayor, of the police shooting of a Black teenager.

Jen Psaki, a transition spokeswoman, responded in a briefing for reporters Friday, saying, “I would encourage people to wait until we’ve made even one announcement about a Cabinet member — and certainly more than just a dozen White House names — before they pass judgment.”

Progressives and moderates alike praised Klain’s appointment as chief of staff. Members of the so-called Squad of progressive House Democratic women of color, including Rep. Alexandria Ocasio-Cortez of New York, gave him high marks for his willingness to listen.

Still, Biden’s honeymoon may be short. Ocasio-Cortez and her colleagues Thursday spoke at a Sunrise Movement demonstration in front of the Democratic National Committee headquarters, with a “BIDEN BE BRAVE” banner unfurled, to demand that the president-elect not falter in pursuing the aggressive climate policies he ran on.

“That’s what our next move is, to make sure the Biden administration keep its promise,” Ocasio-Cortez said. “We have to organize for it. We have to bring the heat for it.”

Trump campaign faces lawsuit for ‘disenfranchising black voters’ in 

efforts to overturn Michigan

 election result

A poll worker prepares to start counting ballots during the 2020 general election in Detroit, Michigan on 3 November. Source: Getty Images

Republicans have asked for a delay of two weeks to allow for a full audit of results in Wayne County, home to majority-black Detroit, that was overwhelmingly won by Joe Biden.

A group of Detroit voters is suing Donald Trump and his campaign for attempting to overturn the election result in Michigan, claiming it is openly seeking to disenfranchise black voters.

A lawsuit, filed in a DC federal court on Friday, describes the Trump campaign’s allegations of voter fraud as one of the “worst abuses in our nation’s history”, accusing it of attempting to “intimidate” and “coerce” Michigan state and local officials into replacing electors.

Republicans have asked for a delay of two weeks to allow for a full audit of results in Wayne County, the state's largest county and home to majority-black Detroit. It was won overwhelmingly by president-elect Joe Biden.

"To effectuate this strategy, defendants are openly seeking to disenfranchise black voters, including voters in Detroit, Michigan," the lawsuit read.


READ MORE

Observers for Donald Trump are being accused of obstructing the vote recount in Wisconsin

More than three quarters of Detroit residents are black, according to US census data.

“Central to this strategy is disenfranchising voters in predominately black cities,” the suit alleges.

“Repeating false claims of voter fraud, which have been thoroughly debunked, Defendants are pressuring state and local officials in Michigan not to count votes from Wayne County, Michigan (where Detroit is the county seat), and thereby disenfranchise hundreds of thousands of voters.”





After his court defeat in Pennsylvania, Donald Trump faces new pressure to concede the election



Mr Trump has repeatedly falsely accused several cities, including Detroit and Philadelphia, of orchestrating a massive election fraud.

His campaign has claimed, without evidence, that mail-in voting was corrupt.

“No more,” the lawsuit says. “The Voting Rights Act of 1965 flatly prohibits Defendants’ efforts to disenfranchise black people and assault our Republic.”


READ MORE


Joe Biden denounces Donald Trump's 'irresponsible' fight to reverse the election results


Michigan's board of canvassers, which includes two Democrats and two Republicans, is due to meet on Monday to certify the results.

Republican Party national committee chairwoman, Ronna McDaniel, and the party's Michigan chair, Laura Cox, called on the board to "adjourn for 14 days to allow for a full audit and investigation into those anomalies and irregularities".

Michigan's Secretary of State Jocelyn Benson has said that audits cannot be conducted until after certification because officials do not have legal access to the documents needed until then.

On Saturday, Ms Benson posted on Twitter that there had been "no evidence" to draw into question the result of the election.



In a nutshell:
✅5.5m Michigan citizens voted ✅The results of their votes are clear
✅No evidence has emerged to undermine that
✅We have rules & laws in place to protect the integrity of our elections & the will of the voters
✅ Those rules & laws should govern the days ahead. https://t.co/msMw041OM7— Jocelyn Benson (@JocelynBenson) November 21, 2020

Mr Trump has rarely appeared in public since his electoral loss, but has not given up on his provocative Twitter campaign.

Meanwhile, a Pennsylvania judge on Saturday threw out Mr Trump's claims of widespread electoral fraud there.

The decision - announced in a scathing judgment which excoriated the Trump team's legal strategy - paves the way for Pennsylvania to certify Democrat Joe Biden's victory in the state, which is scheduled to take place on Monday.


READ MORE


After a Joe Biden win was confirmed in Georgia, Michigan leaders dealt Donald Trump another setback



Judge Matthew Brann wrote in his ruling that Mr Trump's team had presented "strained legal arguments without merit and speculative accusations" in their complaints about mail-in ballots in Pennsylvania.

"In the United States of America, this cannot justify the disenfranchisement of a single voter, let alone all the voters of its sixth most populated state," Justice Brann wrote.

"Our people, laws, and institutions demand more."

Only a limited number of Republicans have so far recognised Mr Biden as the winner and called on Mr Trump to concede.

The Pennsylvania court ruling prompted a Republican senator from the state, Pat Toomey, to join those ranks, saying Biden "won the 2020 election and will become the 46th president of the United States".

"President Trump should accept the outcome of the election and facilitate the presidential transition process," Mr Toomey said in a statement that congratulated Mr Biden while specifying he voted for Mr Trump.

- Additional reporting by AFP.