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Cambridge University Science Magazine
The climate crisis is upon us. Decades’ worth of unrelenting greenhouse gas emissions are warming the planet, leading to a breakdown in once-reliable climate systems. The effects of climate breakdown pervade many aspects of human society and life on Earth in general. A changing climate affects agriculture, water resources, ecosystem integrity, ocean acidity, and a multitude of other aspects of the world. But the most striking of these, the moments that shock us into silence, that leave us grasping at straws due to the sheer scale of them, are extreme weather events.

Hurricanes, flash floods, heatwaves, and wildfires are all natural features of the planet’s weather system. But as global temperatures rise, these events are becoming more severe and more likely to occur. Globally, this puts us in a position where natural disasters seem to be happening constantly; we are still reeling from one while the next one looms on the not-too-distant horizon. The summer of 2019 saw swathes of the Amazon on fire, followed by Hurricane Dorian hitting the Bahamas at the start of September. In another hemisphere, the Australian bushfire season was starting early in September and October, and lasted right through until January, at which point there was mass flooding in Jakarta, Indonesia. These are just the disasters that made headlines.

These natural disasters have devastating impacts on human lives and livelihoods, as well as the rest of the natural environment. To understand the extent of these impacts,

we must first understand how extreme weather events come about, and how they link into the greater story of climate breakdown. A key part of this is recognising that global climate systems and ecosystems are interconnected, and changing one part has knock-on effects for the entire planet. To quote fantasy author Ursula K. Le Guin, 'Rain on Roke may be drought in Osskil... a calm in the East may be storm and ruin in the West'. Here, we focus on two recent natural disasters that unfolded concurrently — the Australian bushfire season, and flash flooding in Jakarta —and look at how they tie into the greater story of climate and ecological breakdown.

A World on Fire

The past few months have seen some of the largest bushfires in Australian history; across the country, 110,000 sq km have been engulfed in fire. Social media was inundated with dramatic images of great columns of smoke stretching into the heavens, and of whole cities turned a hellish orange by the ash and glow of nearby fires. At least 33 people have died as a result of the fires — four of them firefighters — and ecologists at the University of Sydney estimate more than a billion animals have been killed. Bushfires are normal for this time of year, but this fire season has been long-lasting and widespread.

It is a painfully in-your-face indictment of global warming that these wildfires come at the end of Australia’s hottest year on record. In December 2019, Australia’s temperature record was broken twice (on consecutive days) to reach 41.9 ̊C, with the 2019 mean temperature more than 1.5 ̊C higher than average. For reference, the Intergovernmental Panel on Climate Change (IPCC) recommends that the global average temperature should be prevented from increasing by more than 1.5 °C. They forecast that at current emission rates, and thus warming rates, the average global temperature could reach this mark as early as 2030. Looking at 2019, Australia appears to be worryingly ahead of the curve, and this should serve as a warning to the rest of the world as to what a 1.5 ̊C temperature increase means in reality.

High temperatures alone are not the only meteorological driving force behind bushfires. 2019 was also an unusually dry year, thanks largely to a climate phenomenon called the Indian Ocean Dipole (IOD), the Indian Ocean’s answer to the more famous El Niño - Southern Oscillation weather system of the Pacific Ocean. The IOD is the result of a difference in sea surface temperature between one side of the Indian Ocean (off the east coast of Africa) and the other (closer to South East Asia and Australia). The dipole exists in a balance; if one side of the Indian Ocean is significantly warmer than usual, the other side will be cooler. A warmer ocean experiences more evaporation and in turn nearby land experiences more rainfall. Both El Niño and the IOD demonstrate the delicate, interconnected nature of coupled climate systems.

In 2019 this balance was tipped to its extreme, which resulted in both the bone-dry conditions needed to start an early fire season in Australia, and months of extreme rainfall and flash flooding across East Africa. The IOD is a natural phenomenon — an intrinsic part of Earth’s complex climate system — and extreme IOD events have occured before. However, in 2014 climatologists from institutions across Australia, India, China, and Japan projected that under increasing CO2 concentrations in the atmosphere, extreme IOD events would increase in incidence from one every 17 years to one every 6 years. The increasing occurrence of these dry periods over Australia, in combination with what are sure to be many more years of record breaking temperatures, presents a bleak outlook for future Australian summers.

Extreme weather events rarely occur in isolation, and the IOD is a prime example. While Australia was burning, Djibouti, Ethiopia, Somalia, Kenya, and other countries in the Horn of Africa were enduring up to 300% of their average rainfall, resulting in over 300 deaths across the region. Similarly, the fires in southeast Australia were so extensive that the ash released was able to cross the Tasman Sea and blacken glaciers in New Zealand. Darker colours absorb more heat than lighter colours, which is why you will feel cooler in summer in a white top than a black one. Here, this means that the blackened glaciers are melting more quickly than normal. A sure-fire sign of a crisis: fires Australia melting glaciers in New Zealand.

While high temperatures and minimal rainfall create conditions ripe for mega-fires, there is a third, often overlooked, contribution to the increasing coverage of fires in the Australian bush; the way the land is managed. In a country where fires are inevitable, land management means the difference between small, controlled burns and wildfires running across the land. There are two broad schools of thought when it comes to land management for fire reduction: hot burns and cool burns. Hot burning is practiced by many Western governments, including the Australian government, and it is quite literally a scorched- earth tactic, in which areas of land near to settlements are burnt to the ground to deplete the fuel of any would-be wildfires. This is known as ‘backburning’ and while it can stop fires making it right up to towns and cities, it doesn’t address the build-up of fuel away from settlements, which can lead to worse fires in the long term.

In contrast, cool burns are smaller fires set at more regular intervals before the dry season to reduce fuel while protecting biodiversity. They are practiced by Aboriginal and Torres Strait Islander Peoples across Australia, and have an emphasis on being tailored to the local environment and ecology. In recent decades, First Nation Peoples of Australia have had their access to the land restricted, and management has been taken over by governmental bodies. 'The fact of the matter is that we don’t have the expertise in the current land management sector to look after the landscape the right way' Victor Steffensen, an Indigenous fire practitioner, told ABC at their Bushfires Special in February. 'We have a landscape now that is just full of fuel, and it’s just backed up to the communities... We need to start training people to read landscapes, understand the soil and understand when to burn the right ecosystems at the right time'.

First Nations Peoples have been in Australia and practicing fire stewardship for 65,000 years. Their relationship with land embodies the fact that humans are a part of the ecosystem, and how we act has profound effects on the rest of the natural world. Steffensen goes on to explain how human factors compound to create the natural disasters we are increasingly facing. 'It’s about all of it. We need to get the scientists to help us reduce emissions, and we need to get communities and people out on country[side], learning about the environment and reconnecting with the landscape again, just as Aboriginal Peoples have done for thousands of years'.

A World Under Water

While the world was watching Australia burn, another disaster was unfolding in Jakarta, the capital city of Indonesia. On New Year’s Eve Jakarta experienced the highest level of rainfall in a single day since records began,at the time of Dutch colonisation in the 1800s. This was the start of more than a week of unrelenting downpours, during which more than 60 people died and some 180 neighbourhoods across the city were flooded. Parts of the city were left under 19 feet of water and other regions were hit by devastating landslides which killed at least a dozen people. The central urban region of Jakarta is of an equivalent size to London; a population of about 10 million and covering a similar land area. Picture flooding throughout almost 200 neighbourhoods across London, with Camden Market under two stories of water; this is the extent of the disaster that hit Jakarta.

An increasingly common question when natural disasters hit is 'was this one caused by climate change?'. After all, Jakarta’s monsoon season stretches over eight months of the year, from October to May, so it is not uncommon to see heavy rainfall. It is tempting then to view this as simply a strong storm, an extreme outlier in what is already a complex system. But this is not an event which exists in isolation — Jakarta’s monsoons are one part of a network of weather systems all trapped within one warming planet.

In their 2019 Special Report on the Ocean and Cryosphere, the IPCC outlined how coastal ecosystems and communities can expect to be impacted by global warming and the consequent rising sea levels. Following our current warming trajectory, the IPCC calculate that extreme sea level events — like the storm which hit Jakarta — could increase in frequency from once-a-century events to once-a-year events by 2050. As with all extreme weather events, it isn’t possible to assign blame for the flooding to climate change alone, but we do know that these events are made more likely under global warming. This was recognised by Dwikorita Karnawati, Director of the Indonesian Agency for Meteorology, Climatology, and Geophysics, when she told reporters 'the impact of a one degree increase can be severe... Among that is these floods'.

As a low-lying island nation with a long coastline, Indonesia is in a precarious position, trapped between increasing rainfall and rising sea-levels. To make matters worse, Jakarta is sinking. The city sits on an aquifer, an underground layer of water-bearing material, that is being pumped out for use by industry and residents, to such a degree that in some parts of the city the land sinks by 10 inches every year. Researchers at the Bandung Institute of Technology forecast that by mid-century 95% of North Jakarta will be underwater if preventative measures are not put in place. By pumping out groundwater, Jakarta is pulling its legs out from under itself, and exacerbating its susceptibility to the effects of the changing climate.

Jakarta’s precarious situation will likely see many of its residents leave, if they are able to; the government has announced that the site of the capital will move in 2024. Climate migrancy is something we will see more of as extreme weather events intensify; sociologists at Cornell University predict that in the next 40 years, 1.4 billion people will be forced to migrate due to the effects of climate breakdown. But it might not be too late for Jakarta. Other coastal cities have faced similar degrees of sinking and changed course (to varying degrees of success). In the 1960s, for example, Tokyo halted the pumping of groundwater after finding that the city had sunk three metres since the start of the century. By the mid ‘70s, the city’s water was being piped in from beyond city limits, and sinking had also been halted (at just over four metres). Jakarta, however, doesn’t look set to stop its groundwater pumping anytime soon, opting instead to start work on a $4 billion, 40 km-long sea wall across Jakarta Bay. This would act as a water-break for the storm surges that threaten the sinking city, and would decrease the impact of rising sea levels on the current inner sea walls.

While it might lessen the immediate threats of flooding and storm surges, a sea wall would bring environmental problems of its own. 'As the water is trapped, the pollutants deposited by the 13 rivers in Jakarta would accumulate in one place' Taslim Arifin, a researcher at the Research and Development Center for Marine and Coastal Resources told the Jakarta Post. 'The water inside the seawall would become a big pond of pollution'. As well as forming the perfect conditions for the spread of water-borne diseases, the pollution would threaten the coral reefs of Jakarta bay and the condition of fish sourced from the bay. An alliance of local community groups, collectively called the Save the Jakarta Bay Coalition, wrote in an open letter 'We are deeply concerned about the livelihood loss and infringement of human rights, as well as irreparable environmental damage, caused by the project... Tens of thousands of people connected to small-scale fisheries will lose their livelihood'.

There are other solutions to saving a sinking city. Upon accounting for the destruction of forest and peatland carbon stores, Indonesia is the fifth-largest emitter of greenhouse gases in the world. If it wants to stave off the rising tides, that seems like a good place to start. Like many other formerly colonised nations, it has been industrialising rapidly to keep pace with the developed world, and this comes at the expense of the environment. However, with almost a quarter of Indonesian citizens denying the reality of climate breakdown, there may need to be a wider change in mentality before action will be taken to ensure climate justice for Indonesia.

A World Shared

Whether looking at fires in Australia, flooding in Indonesia or other extreme weather events, human lives are never the only ones at stake. The story of climate breakdown is one that threatens both humanity and the wider ecosystem that we are a part of, and indeed depend on.

The First Nations Peoples of Australia are a prime example of the interdependence between humans and the natural environment. Their understanding of the surrounding ecosystem has allowed them to safeguard unique animals and plants, using them within ecological limits. The Australian habitats, which have existed in geographical isolation for millions of years, have provided the perfect setting for high rates of speciation. However, this isolation also renders these ecosystems especially vulnerable to change, as exemplified by the extinction of many species following the loss of Aboriginal practices and the introduction of invasive species upon the arrival of European colonists in the 18th century. Australia lost 29 mammals following the arrival of Europeans, whereas North America only lost one mammal.

The Australian landscape was forged in flames, allowing many species to evolve adaptations that enable them to survive and thrive in such harsh conditions, such as Banksia plants which scientists at Curtin University discovered have evolved with fire for 61 million years. These plants display innovative adaptations, such as containing the seeds within cones which are melted by the fire, meaning wildfire is required for them to release their seeds and resprout. What they haven’t had time to evolve defences towards, however, is the scale, intensity, and timing of the current fires. These fires go beyond the limits of their current adaptations.

The loss of biodiversity within Australia is particularly prominent as many native species aren’t found anywhere else in the world. Already, it is estimated that the fires

have pushed at least 20 species towards extinction. This number could rise to 100, and amongst the endangered is Kangaroo Island’s distinctive glossy black cockatoo, for which the island was its last refuge. This cockatoo species had rebounded from near extinction and reached record numbers in 2019, but the recent wildfires have devastated the birds’ natural habitat and destroyed their only food source: seeds from the drooping she-oak. Similarly, the entire habitat and all known monitoring sites of the Kangaroo Island dunnart have been burnt, pushing them towards the brink of extinction. At this rate, it is possible that species could become extinct before we’ve even had the chance to discover them. Only a third of Australia’s 250,000 insect species have been named. Names crossed out after millions of years of evolution before we can even write them down.

Entomologist at the University of Sydney Tanya Latty is trying to address this threat, telling the Times that the endemic short-range velvet worms studied by her lab may be used for a captive breeding programme in order to save the species. 'As an ecologist' Latty said, 'it’s a very tragic thing to find yourself having to think “What if my species is now extinct?”'.

Even for those animals that survive the immediate danger of the wildfires, the knock-on effects of the fire can have an equally devastating impact on the ecosystem. Species may suffer from the resulting lack of food and the loss of shelter, leaving them vulnerable to predators. Any subsequent rain would also wash large quantities of ash and soot into rivers and lakes, developing algal blooms and endangering aquatic life.

While nature is often threatened by a changing climate and the extreme weather events it brings, it is also a part of the remedy. In the case of Indonesia, man-made solutions, such as building a sea wall, provide an expensive plaster to a worsening issue that isn’t skin deep. But there exist alternatives to these gray solutions, known as 'blue and green infrastructure' which seek to strengthen and use existing natural defences, such as building vegetative river banks and wetlands to combat the effects of coastal erosion.

Mangroves, the salt-tolerant trees that reside in the intertidal zones of coastlines in tropical and sub-tropical regions, have been dubbed ‘green coastal guardians’. Thanks to their complex root system, mangroves act as an eco-buffer which stabilise coastlines, reduce erosion, store carbon, provide habitats for fish, and enhance ecosystem stability. Mangroves are also incredibly effective at removing carbon from the atmosphere, with their mean long-term carbon burial rates more than 45 times greater than tropical and boreal forests.

With 3 million hectares along its coastline, Indonesia harbours 23% of the world’s mangrove forests. Yet rather than protecting these vital ecosystems, the Indonesian government has done nothing to stop companies from burning mangrove forests to make way for palm oil plantations, which severely affects coastal ecosystems and releases the stored carbon in these ecosystems. This deforestation results in the release of 190 million metric tonnes of CO2 per year, accounting for one fifth of Indonesia’s land use emissions. According to the UN Food and Agriculture Organization (FAO), 40% of Indonesia’s mangrove forests have been destroyed since the 1980s. The shoreline on central Java has suffered in particular, the damage compounded by conversions of mangrove forest for aquaculture, groundwater extraction, and infrastructure development. To address this risk posed to the 30 million inhabitants of Java, initiatives such as the ‘Building with Nature’ Indonesia project, work to restore mangroves in order to protect against erosion, improve water purification, increase carbon storage, revive fisheries, and offer further opportunities for recreation and tourism. It is hoped that nature-based projects such as this can provide sustainable, long-term solutions to the coastal communities most at risk from climate breakdown.

It is important that we don’t decouple nature’s survival from our own. Without the complex networks of fungi, microbes, plants, and animals that support ecosystems, food security becomes threatened and disease more easily spread. Pairing the extreme weather changes with additional urbanisation and invasive species introduction has the potential to lead to unknown consequences and tipping points within nature and human society.

In both Jakarta and Australia, the loss of human life was echoed by widespread environmental destruction. The governments and industries of these two countries are deeply invested in the extractive industries that produced these phenomena; in fact Indonesia and Australia are the two biggest exporters of coal in the world. There is a hypocrisy here, in that the people profiting from this industry are not the ones affected by the resulting disasters. Take Jakarta: in a country of extreme inequality, in which the richest 10 % of the population own 77 % of the wealth, the people that died in the flooding were more likely to have lived in the city’s slums than its skyscrapers.

This trend is true across the globe, as we see governments continue to clear forests and invest in fossil fuels while their citizens are battered by storms and fires. It is difficult to imagine this situation changing while economic growth increases the demand for our planet’s finite resources. Speaking at the Oscars, Bong Joon-ho, Director of Parasite, expressed this simply — ‘we all live in the same country now: that of capitalism’. The events that unfolded in Jakarta and Australia — their causes, who was affected, our collective response to them — tell us a lot about the new era that we are entering. An era in which megafires and superfloods are no longer rare. An era in which food systems are threatened, and billions of people may be forced into migration. An era brought on by blind faith in capitalism as a system of governance and as an ethical compass. As we move together through the 21st century, we need to ask whether this system has the answers to the questions that are burning down our homes, and if not, if there are other systems of knowledge that do. When responding to natural disasters, we will need to decide whether we want to work against nature or work with it; whether we want to build sea walls or plant mangrove forests.

Evan Wroe is a PhD student in Chemistry at Queens' College and Annika Schlemm is an MPhil student in Biological Sciences (Zoology) at Queens' College. Artwork by Rosanna Rann