The causes, pace, and nature of the environmental changes we are forcing on our planet day by day, hour by hour, is an issue I am passionate about – and which concerns me greatly. 

I’ve previously written about the growing risks posed by wildfires, desertification and increasing global temperatures.  And about strengthening food security and water availability for communities around the world.  These are all big global challenges that require a big global response.  But there is one environmental issue that feeds into all these problems.   Something we may not notice for much of the time, but which has the potential to unleash untold environmental and financial damage to our society.  And that is: the weather.  In particular, its increasing unpredictability.

Dozens of billion-dollar weather disasters hit the Earth in 2022, making it, for one example, the second costliest year on record for drought[1].  There were also three mega-disasters costing at least US$ 29 billion[2], plus a heat wave that caused chaos in Europe[3], not to mention monsoon floods in India and Pakistan that brought death and destruction to thousands of communities. 

We are not even half-way through 2023 and we have already had floods in California, temperatures of -28oC in Afghanistan and, in Europe, ski resorts closing because it is too warm for snow[4].  In southern Africa, Cyclone Freddy displaced more than 80,000 people across Mozambique, Malawi and Madagascar and is one of the longest-lived storms ever recorded in the Southern Hemisphere.  The second longest was in 2016. 

In April 2023, a tornado ripped through Rolling Fork, a small town in Mississippi, USA, killing 25 people.  Even for a tornado it seems to have been extraordinary.  Preliminary findings have registered the tornado a four on the Enhanced Fujita (EF) scale, meaning it had a three-second gust of 166 to 200 mph, and flung debris 30,000 feet (9km) up into the air[5].  The National Weather Service in the US commented that this type of storm is rare and one of the most destructive.

Impact of climate on the weather 

The link between climate change and extreme weather events is well established.  Thanks to greenhouse gases – human-generated – the Earth’s lower atmosphere is getting moister and warmer, creating the conditions where there is more energy for storms and other types of extreme weather events[6].  ‘Extreme weather events’ are defined by scientists as those that are unlike 90%-95% of previous weather events in the same region. 

Heavy rainfall and snowfall events that increase the risk of flooding are becoming more frequent.  Rising global temperatures are making heat waves more common, severe, and lengthy, as I discussed in my previous article on wildfires.  The 2018 National Climate Assessment found the frequency of US heat waves has tripled since the 1960s and the average heat-wave season has increased by 45 days[7].  The UN Intergovernmental Panel on Climate Change (IPCC) expects a similar trend across the planet.

As they happen more frequently and last longer, simultaneous heat waves in different locations are occurring more often, giving rise to a new term: “concurrent heat wave”.  This is when any two regions in the mid latitudes simultaneously experience large heat waves.  In the 1980s, concurrent heat waves only occurred for 20-30 days each summer.  In the 2020s, they happen almost every day in the summer season.  Global warming has driven a sixfold increase in the frequency of simultaneous heat waves over the last 40 years – and they are covering about 46% more space and reaching maximum intensities that are 17% higher than 40 years ago[8].

Another consequence of higher temperatures is increasingly vicious hurricanes as warmer oceans combine with the warmer and moister atmosphere.  The strongest hurricanes will be more intense, produce more rainfall, affect new areas, and possibly be larger and longer-lived.  This is further complicated by the rise in sea levels caused by the melting polar icecaps, meaning even more seawater is pushed on to shore during coastal storms.  More seawater plus more rainfall produced equals more destructive storm surges and flooding. 

Changing weather systems

While we know global warming is likely to make hurricanes more intense, it is not clear if it will also make them more frequent.  Similarly, we cannot be sure whether or not there will be more tornadoes, even though some of the conditions that create tornadoes will increase with global warming, because other factors – such as changes in the vertical and horizontal variations of winds – are uncertain.

Weather systems are complex and there are many factors that contribute to any individual extreme weather event.  El Niño and La Niña, for example, are the biggest fluctuations in the Earth’s climate system[9] and can have consequences for weather patterns across the globe.

El Niño refers to the warming of sea surface temperature that occurs every few years, typically concentrated in the central-east equatorial Pacific.  An El Niño is declared when sea temperatures in the region rise 0.5⁰C above the long-term average, which tends to mean warmer than average weather in the eastern Pacific.  La Niña is the opposite side of the fluctuation, which sees cooler than average temperatures in the equatorial Pacific region, leading to cooler, drier weather.

Both El Niño and La Niña affect patterns of rainfall, atmospheric pressure, and global atmospheric circulation, the large-scale movement of air that, together with ocean currents, distributes thermal energy on the surface of Earth.  These changes are the main sources of variability in climate for many areas worldwide.  Together, El Niño and La Niña are known as the El Niño-Southern Oscillation (ENSO), with oscillation referring to the changes in atmospheric pressure between the east and west tropical Pacific that accompany El Niño and La Niña episodes in the sea.  

Research shows that the ENSO cycle has impacts all over the world.  For example, El Niño years can increase the risk of colder winters in the UK and cooler, wetter weather in the southern United States, and reduce the likelihood of tropical storms in the North Atlantic.  La Niña, meanwhile, does the opposite, and can make tropical storms more likely in the Atlantic, monsoons in Southeast Asia more severe, and increase the risk of flooding in Australia, for example.

Causes uncertain

El Niño and La Niña are epic patterns of natural climate variability, caused by many interacting factors.  “Every event is a combination of climate change and climate variability,” observes Caroline Wainwright[10], a climate scientist at Imperial College London.  This makes it difficult to attribute any specific extreme event to human-caused climate change, a nuance that enables climate change sceptics to argue that “there has always been extreme weather”.  Yet studies do show that, in general, a warming climate makes an event more severe or more likely to happen[11].

The recent floods in Pakistan that submerged a third of the country shows how multiple factors might come into play.  For every extra degree Celsius, there is an extra 7% moisture in the air, so there will be more extreme rainfall and greater risk of flooding.  Global warming also affects glaciers high up in the mountains, so the spring thaw is joined by water that has previously been locked up in the ice.  In 2022, unusually high temperatures in the Himalayas melted glaciers, adding to pressure on the Indus River and other waterways struggling to contain the torrential rain of the La Niña-affected monsoon.  Pakistan, as a whole, received 243% more rainfall than usual during this period, the wettest August since records began in 1961[12].

The uncertainty in determining what is happening to the world’s weather is increased because we do not really understand how a phenomenon such as the ENSO cycle might itself be affected by climate change.  2022, for example, was the third year in a row where La Niña occurred, the first time this century such a “triple dip” has been recorded.  Ordinarily, ENSO operates on a three- to seven-year cycle, with strong El Niños tending to be followed by a balancing La Niña. 

La Niña years are also getting warmer, as well as more frequent.  In March 2022, the authorities responsible for the Great Barrier Reef in Australia announced the coral reef had experienced a mass bleaching event, in which corals expel their symbiotic algae as a reaction to rising temperatures[13].  Only the sixth such event of modern times, it was also the first to take place in a La Niña year.  2020’s La Niña may well be a harbinger of those to come, with higher temperatures, increased flooding and severe droughts.

Modifying the weather

Faced with the increasing frequency of unusual weather patterns, some countries have tried to give nature a helping hand by using a technique known as ‘cloud seeding’ to modify the amount or type of precipitation produced by clouds.  While others have tried to mitigate its effects by reinforcing their infrastructure.  In the short term, such efforts are well intentioned.  But there is a risk that by directly interfering in weather patterns that are far more powerful than we fully understand, we fall victim to the law of unintended consequences.  This is exemplified by the story of the man once regarded as the greatest inventor in the world, Thomas Midgley Junior[14]

Thomas Midgley Junior invented the process for putting lead in petrol, which made the internal combustion engine more efficient, and creating Freon, the first ever CFC, that enabled refrigerators to operate safely.  So faster, more powerful cars and colder, more efficient fridges.  A double winner!  It was only decades afterwards that we discovered the effects of both innovations were more far-reaching than Midgley could ever have forecast. 

Not only did leaded petrol cause heart disease, strokes and cancer,[15] but it also increased lead concentrations in polar ice cores by 350%, while CFCs were the original ‘greenhouse gases’ that tore a hole in the ozone layer and first propelled the idea of climate change into the public consciousness. 

Cloud seeding is claimed to improve a cloud’s ability to produce rain or snow by introducing tiny ice nuclei, such as silver iodide, into certain types of subfreezing clouds.  These nuclei provide a base for snowflakes to form.  South-East Asian countries use the technique to clear dry-season haze, while ski resorts in America use it to keep their pistes in good condition[16]

Recently, the United Arab Emirates (UAE) began one of the world’s largest cloud-seeding programs, flying some 200 missions a year from an airfield in Abu Dhabi.  Even this is dwarfed by China[17], which spends at least US$ 200 million a year on its program.  In 2018, this covered 5 million square kilometers, or more than half of China’s land territory, with plans to expand this area by around 100,000 square kilometers each year.  The government says that cloud-seeding produces about 50 billion cubic meters of extra rain or snow across the country each year — equal to about 8% of total water demand.  While in the parched capital, Beijing, seeding can reportedly boost rainfall by 15%. 

Despite these huge investments, however, independent scientific data on the efficacy of cloud seeding is less than convincing.  In 2019, scientists affiliated with the World Meteorological Organization noted that rainmaking activities were often based on “empty promises rather than sound science”[18].  Recent advances in radar and computer modelling have made rigorous tests more possible.  The scientific consensus is that cloud-seeding can slightly augment snowfall in certain contexts[19], but rarely on the scale claimed by its supporters.

There are two other main types of weather modification aimed at taming some of the extremes[20] increasingly being experienced.  One involves fertilizing the ocean to increase its carbon uptake, while the other focuses on brightening clouds or ice to reflect more sunlight and reduce global or local warming.

The Arctic Ice Project[21], an NGO, plans to deploy small hollow glass beads made of silicon dioxide over parts of the Arctic Sea’s ice and the Arctic Ocean to increase reflectivity and slow global warming.  Meanwhile, Australian universities are testing a salt spray over the Great Barrier Reef to reflect more sunlight and protect the reef, in a process known as ‘cloud brightening’.

However, the medium to long-term impact of many of these weather modification technologies is still unclear.  For instance, there are concerns that cloud brightening could have adverse effects on ecological systems, agriculture, and global warming.

The IPCC[22] warns that cloud brightening could deplete the ozone layer and alter regional weather patterns, while doing little to reduce ocean acidification.  Moreover, to meaningfully reduce global warming, cloud brightening would need to occur for a sustained period of time.  If it were to cease, due to policy changes, financial constraints or geopolitical issues, there is a fear that global warming could rebound even stronger than it was previously.   

Adaptation not prevention?

Given the uncertainties around weather modification technologies, should we simply focus our efforts on adapting to the changing climate and the increasing risk of extreme weather?   

Here, too, the best route forward is far from clear.  It is one of the unfortunate ironies of climate change and extreme weather events that those communities most at risk are often those with the fewest resources to cope.  For example, in the summer of 2021, temperatures in British Columbia on the Pacific seaboard of Canada hit 49.6°C[23].  At the same time, temperatures in Iraq exceeded 50°C, leading to widespread power cuts.  The heatwave in Canada was more unusual than the one in Iraq, yet Canada has the resources to withstand such as situation.  Iraq does not.

There is also the not inconsiderable risk, highlighted in the IPCC’s 2022 assessment report[24], that we inadvertently cause more harm than good with our efforts to hold back the immediate effects of extreme weather events.  For example, constructing a sea wall to protect a community from rising sea levels and storm surges might change the pattern of currents by the coast, creating worse erosion elsewhere, and interfere with local fish stocks, negatively affecting marine biodiversity.  Or building a river-fed irrigation system in an area with inconsistent rainfall could lead to overconsumption of river water, leaving people downstream with less. 

These kinds of measures can also create a false sense of security.  There is evidence in Bangladesh[25], for example, that building levees to protect people from flooding from the Jamuna river is actually encouraging more people to live on the floodplain, because they believe they will be protected by the levees.  But this puts more people at risk if a levee should break.   

Balancing act

The one conclusion we can make in these circumstances is that whatever we do, we have to balance these two priorities.  We cannot act now to mitigate the impacts of extreme weather if it leads to additional, or worse, problems in the future.  But nor can we focus all our attention on the future, at the expense of the millions of people around the world who are increasingly threated by unpredictable weather.  We have to try to do both.  We must double-down on the net zero transformation and our attempts to slow down the rate of global warming, while also investing the best of our knowledge, technologies and resources in mitigating the effects of the extreme weather events that climate change seems to provoke. 

I’m proud to say that, for Abdul Latif Jameel at least, these are not just words, and we have – as they say – put our money where our mouth is.  The Jameel Observatory Climate Resilience Early Warning System Network (Jameel Observatory-CREWSnet), a joint project from Massachusetts Institute of Technology (MIT) and Community Jameel, was selected as an ‘innovation sprint’ at the 2023 summit of the Agriculture Innovation Mission for Climate (AIM4C).

AIM4C is a joint initiative of the United States and United Arab Emirates that seeks to enhance climate action by accelerating agriculture and food systems innovation and investment.  Innovation sprints are selected by AIM4C to accelerate their impact following a competitive process that considers scientific excellence and financial support.

The Jameel Observatory-CREWSnet[26], one of MIT’s five Climate Grand Challenges flagship projects, aims to empower communities worldwide to adapt to climate shocks by combining state-of-the-art climate and socioeconomic forecasting techniques with technological solutions.  The first trials will be in Bangladesh and Sudan, where farmers will not only get weather forecasts but also the tools – such as heat resistant seeds and targeted fertilisers – to react.  Our aim is to provide enough information on the weather to come for communities to prepare and manage the risk.  We are bringing the research out of the laboratory and into the field, where it can help to alleviate poverty through improved productivity.

Slowing down the rate at which the planet is warming while softening the blow of climate change is a challenge.  Yet it is a challenge we must come to terms with, and one we must accomplish.  It certainly won’t be easy.  But the consequences of failure are nothing short of catastrophic.




















[19] 5th paragraph