Life

by Tim Flannery

  The addition of a floating platform supporting solar panels, facilities such as accommodation (if the farms are not fully automated), refrigeration and processing equipment tethered to the floating framework would enhance the efficiency and viability of the permaculture arrays, as well as a dock for ships carrying produce to market.

  Given its phenomenal growth rate, the kelp could be cut on a ninety-day rotation basis. It’s possible that the only processing required would be the cutting of the kelp from the buoyancy devices and the disposal of the fronds overboard to sink. Once in the ocean depths, the carbon the kelp contains is essentially out of circulation and cannot return to the atmosphere. The deep waters of the central Pacific are exceptionally still. A friend who explores mid-ocean ridges in a submersible once told me about filleting a fish for dinner, then discovering the filleted remains the next morning, four kilometres down and directly below his ship. So it’s likely that the seaweed fronds would sink, at least initially, though gases from decomposition may later cause some to rise if they are not consumed quickly. Alternatively, the seaweed could be converted to biochar to produce energy and the char pelletised and discarded overboard. Char, having a mineralised carbon structure, is likely to last well on the seafloor. Likewise, shells and any encrusting organisms could be sunk as a carbon store.

  Once at the bottom of the sea three or more kilometres below, it’s likely that raw kelp, and possibly even to some extent biochar, would be utilised as a food source by bottom-dwelling bacteria and larger organisms such as sea cucumbers. Provided that the decomposing material did not float, this would not matter, because once sunk below about one kilometre from the surface, the carbon in these materials would effectively be removed from the atmosphere for at least 1000 years. If present in large volumes, however, decomposing matter may reduce oxygen levels in the surrounding seawater.

  Large volumes of kelp already reach the ocean floor. Storms in the North Atlantic may deliver enormous volumes of kelp—by some estimates as much as seven gigatonnes at a time—to the 1.8-kilometre-deep ocean floor off the Bahamian Shelf.22 Submarine canyons may also convey large volumes at a more regular rate to the deep ocean floor. The Carmel Canyon, off California, for example, exports large volumes of giant kelp to the ocean depths, and 660 major submarine canyons have been documented worldwide, suggesting that canyons play a significant role in marine carbon transport.23 These natural instances of large-scale sequestration of kelp in the deep ocean offer splendid opportunities to investigate the fate of kelp, and the carbon it contains, in the ocean. They should prepare us well in anticipating any negative or indeed positive impacts on the ocean deep of offshore kelp farming.

  Only entrepreneurs with vision and deep pockets could make such mid-ocean kelp farming a reality. But of course where there are great rewards, there are also considerable risks. One obstacle potential entrepreneurs need not fear, however, is bureaucratic red tape, for much of the mid-oceans remain a global commons. If a global carbon price is ever introduced, the exercise of disposing of the carbon captured by the kelp would transform that part of the business from a small cost to a profit generator. Even without a carbon price, the opportunity to supply huge volumes of high-quality seafood at the same time as making a substantial impact on the climate crisis are considerable incentives for investment in seaweed farming.

  PART V

  Our Twisted DNA

  2018–2019

  The Tree Whisperers

  2018

  DURING THE EXCAVATION of Herod’s palace at Masada between 1963 and 1965, a pottery jar was unearthed that contained a great many seeds of the Judean date palm, which had been extinct for some eight hundred years. The jar had been buried sometime between 155 BC and 64 AD. In 2005, after spending forty years in the archaeological collections at Bar-Ilan University, three of the seeds were planted at Ketura in southern Israel. Eight weeks later, one sprouted, becoming the oldest seed to have germinated with human assistance and the only living example of this variety of palm. Methuselah, as it has been named, reached a height of nearly ten feet in 2015 and revealed that it was male when it started producing pollen. Similar seeds from other archaeological sites around the Dead Sea have since been coaxed to sprout, but unless a female can be raised to produce flowers for Methuselah to pollinate, which would then make viable seeds, the Judean date palm’s resurrection will have been short-lived.

  Methuselah’s story is emblematic of the astonishing potential and the excruciating limitations faced by researchers trying to save the world’s rarest plants. Carlos Magdalena is at the forefront of these efforts, and his The Plant Messiah is a gripping account of both his successes and failures. Magdalena is a Spaniard who had very little formal horticultural training before being employed by the Royal Botanic Gardens at Kew. But he was passionate about plants, and his persistence, and a green thumb fostered by his mother, have yielded incredible results. He is implacably opposed to giving up on a species, no matter how dire its circumstances: ‘I believe that every species has a right to live without justifying its existence.’

  Magdalena made his reputation by saving the café marron, Ramosmannia rodriguesi. A pretty tree with dark-green leaves and white flowers that are borne year-round, it is found only on the island of Rodrigues in the Indian Ocean. First described in the nineteenth century, it was thought to be extinct. But in 1980 a boy collecting material for a school project found a single specimen growing beside a busy road. His teacher was unable to identify it, so sent a dried sample to Kew to see if experts there could help. After a complicated search, they finally identified it as the long-lost café marron.

  Unluckily for the café marron, it is highly prized by Rodrigueans as a folk medicine, credited with the power to treat venereal disease and even banish hangovers. One day when conservationists visited the only known tree, all they found was a stump. A fence was built to protect it, and when that proved insufficient, another. But even this was not enough, so three branches were cut from the resprouted stump and sent to Kew to see if new plants could be grown from them. Of the many cuttings made, just one took root, but from this one many other cuttings have since been propagated. As they grew to sexual maturity a mystery presented itself: despite their year-long flower display, not a single seed was ever produced. And without seeds the species was destined to reside among the living dead, for it could never reproduce in the wild, and its genetically identical clones would always be vulnerable to disease that could cause its extinction.

  When he arrived at Kew, Magdalena was assigned work in a greenhouse where a few café marron cuttings were growing. Attracted by the abundant flowers, he thought that perhaps a way could be found to produce seeds. He felt that the problem was that pollen was not getting to the female part of the flower. So he began cutting into the flowers to open a path for fertilisation. Many experts thought this was misguided or hopeless, but after about 180 attempts Magdalena finally managed to fertilise a single flower. Then he had to wait six months for the seed pod to mature. The seeds were sown, but soon after they sprouted, all of the seedlings died. Undeterred, Magdalena kept experimenting.

  He discovered that if he gave the plants lots of light and heat, more seeds would be set. But even at Kew the precious pods weren’t safe. One morning, when Magdalena went to check his plants, he discovered that a crucial pod-bearing branch had been cut for use in a plant-identification test for students. You can almost hear his shriek of rage rising off the page. But Magdalena is nothing if not persistent, and eventually he raised eight seed pods. The seedlings he grew from them needed protection, so he created a ‘mini-Rodrigues’ at Kew—an island in the hidden corner of a pool where his plants would be safe from the public as well as errant gardeners.

  Sexual reproduction brought genetic diversity to the café marron, as well as the possibility of reintroducing the species to its island home. In 2007, when fifteen seedlings and some seeds were returned to Rodrigues, Magdalena wanted to thank the student who had found that last wild caf
é marron plant, but people kept putting him off. Eventually he learned that the youth had had problems with substance abuse, and had died without learning about his contribution to saving one of the world’s rarest plants.

  The Mascarene Islands group, of which Rodrigues is a part, abounds in endangered species. There remains but a single specimen of the Hyophorbe amaricaulis palm. It grows in the Curepipe Botanic Gardens on Mauritius, where it bears only three to five leaves, and while it occasionally flowers, the male flowers open long before the female ones, so it can only be pollinated with human help. Magdalena has visited this lonely palm several times, but such are the complexities of fertilising it, then obtaining mature fruit, that he has never succeeded in increasing its number. He has, however, come close. Once, staff at the gardens obtained five seeds. But when Magdalena went to collect them, he found one of the garden’s labourers chewing on them. When the outraged Magdalena questioned him, the man replied, ‘We like to eat palm seeds. I have never eaten this species before.’

  In 1990 the last known example of a Mauritian member of the daisy family, the tree-sized Cylindrocline lorencei, died, and all that remained of the species were a few almost-dead seeds. Unable to germinate, they were held in a laboratory at the Conservatoire Botanique National du Brest, in France. Nobody knew what to do until researchers discovered that the last three seeds contained a few living cells. These were extracted from the dead tissue and placed in a solution containing all the nutrients plants require to grow. The microscopic clusters of cells began to proliferate and turned into green, wart-like growths, before transforming into plantlets that could be placed in soil. In 2007 Magdalena took twelve of these plants’ descendants to Mauritius to reintroduce them. The species is heat-sensitive, and eleven died as a result of being quarantined in the Mauritian lowlands. Following the closest brush with extinction imaginable, Cylindrocline lorencei now at least has a chance of surviving, though it is clearly far from secure.

  Lobelias are beautiful flowers much appreciated by gardeners, but there is one species that even the most avid grower will never have seen. Lobelia vagans is a white-flowered form found only on Rodrigues. A few had been growing at Kew, but somehow they were allowed to die out before Magdalena started working there. Luckily, some seeds had been placed in Kew’s seed bank, but when Magdalena went to find them, he discovered that the envelope that supposedly held them was empty. He was about to give up when he carefully examined the sticky margin of the envelope flap. A few seeds had stuck there. Separating the precious seeds from the glue, Magdalena was able to grow and propagate the plant.

  The work done by Magdalena and others like him is nothing short of miraculous. But it is a drop in the ocean, since the global challenge presented by our declining global biodiversity is severe. And it must be said that for all of Magdalena’s professions of single-minded dedication to saving plants from extinction, he seems to find ample time to follow his other great passion—waterlilies. Whole chapters of The Plant Messiah are devoted to his search for unusual waterlilies and other peripheral matters. The book nevertheless illustrates just how much can be done to save even species that all but the greatest optimist would consider doomed.

  The biodiversity crisis is so profound and widespread that even in Europe, species as well as entire ecosystems are under threat. Among the most alarming losses are those of insects. Members of the Krefeld Entomological Society have been collecting insects in the same way in the same parts of the Orbroicher Bruch nature reserve in north-west Germany since 1989. By 2013 they had charted a 78 per cent drop in insect biomass. The causes of the decline have not yet been conclusively identified, though the use of pesticides and the intensification of agriculture are among the prime suspects. As one ecologist commented: ‘We’ve lost huge amounts of habitat, which has certainly contributed…If we turn all the seminatural habitats to wheat and cornfields, then there will be virtually no life in those fields.’1

  Isabella Tree’s Wilding is the story of one couple’s crusade to revive England’s ecosystem. Isabella and her husband, Charles, own the 3500-acre Knepp Estate in West Sussex, which had been farmed by the family for centuries. Their endeavor began in 1999, when they invited Ted Green, an expert on preserving old oak trees, to their estate. Knepp is rich in oaks, some of which are over five hundred years old. But as Green explained, the oaks were in trouble. Some had had their lower limbs removed, depriving them of buttressing, while the root system of others was compromised by ploughing and the death of the mycorrhizal fungi that colonise the roots and are essential to the tree’s health. The sorry state of their beloved oaks left the Trees sensing that something was wrong with the environment at Knepp. But it was economics that led to change: conventional farming was making them broke.

  By 1999 increasing globalisation of the dairy market meant that if the Trees were to remain competitive, they would need to invest £1 million in upgrades to the estate. They were already £1.5 million in debt, so instead of digging themselves deeper, they called in their staff and explained that things could not go on. Their estate manager was devastated to hear that his lifetime’s work was ending in failure, and most of the staff simply could not believe that the estate was no longer profitable. In a ‘funereal atmosphere’ the staff were laid off, and everything from livestock to combine harvesters and semen flasks was sold at auction. As hard as it was, the move paid off. Within a year the EU milk quota fell so low as to be worthless, and then foot-and-mouth disease broke out among sheep and cattle in Britain.

  The Trees had by then embarked on a different venture, having received a grant from the European Union’s agri-environment program to maintain the natural state of 350 acres of the estate. Exceptionally rich in old oaks, this area had, during the nineteenth century, been a deer park. It didn’t take long for the first results to show. Isabella Tree writes, ‘The summer of 2002 was a revelation. Every morning we woke up cradled in undulating prairie…Returning the park to permanent pasture was more than a lifeline to the oak trees: it was proving a tonic for us.’ The biggest factor in the recovery was ending the use of pesticides and herbicides. Wildflowers and insects were emerging everywhere in the old park, returning pleasures, like the deep hum of insect life, that Isabella and Charles had not noticed were missing.

  Fired by their success, and by a visit to the great Dutch rewilding ground at Oostvaardersplassen, they conceived of a grand plan. They would return the entire estate to nature and introduce creatures long gone from the landscape, including beaver and bison. The government’s advisory body, known as English Nature, was, however, unimpressed. Before proceeding, it said, computer models would need to be built so that outcomes could be predicted. Yet for the Trees, ‘the experiment needed to be open-ended, with no specific goal other than the broad expectation of restoring nature’. That opportunity came in 2005, when a change in EU policy allowed them to receive payment for leaving the entire estate fallow.

  Without grazing animals, Knepp would eventually turn into dense forest—an undesirable outcome. So the Trees introduced fallow deer, Tamworth pigs, old English longhorn cattle, and Exmoor ponies—the last three are primitive breeds that share characteristics with their wild ancestors. All were left to interact and reproduce, except where humane considerations or environmental necessity required intervention.

  Knepp’s abundant insects soon attracted rare bats and insectivorous birds, and the cessation of worming treatments for livestock caused dung beetles and earthworms to flourish. As the grazers created varied landscapes and the pigs rooted in the soil, some of Britain’s rarest wildlife appeared.

  Knepp’s neighbours were, however, unimpressed. Rather than a resurgence of nature, they saw weed infestations and an unholy mess. Many viewed it as an affront to their lifetime of efforts and of their heritage. One opined that Knepp ‘feels like a foreign land’; another that ‘it looks totally abandoned, like nobody cares for it anymore’.

  Attitudes hardened further when weeds began to take over. Ragwort, which
is native to England and so a part of its natural ecosystem, is nonetheless regarded as a weed because it can poison livestock. It was certainly proliferating at Knepp, but because of controls around Knepp’s boundary, ragwort seed was highly unlikely to reach neighbouring properties, though this did nothing to allay fears. Creeping thistle, another weed of concern, is also a native plant. It is known as the ‘lettuce from hell thistle’. In 2007 an infestation threatened to engulf large parts of the estate. Tree says that less than a decade earlier ‘we would have been out with the toppers and weedkiller for all we were worth. It took all the courage we could muster to hold our nerve and do nothing.’

  Delivery from the plague came on the wind. The morning of 24 May broke warm and clear, revealing a landscape alive with countless thousands of butterflies called ‘painted ladies’. In the eighteenth century they were known more prosaically as ‘thistle butterflies’, and their caterpillars set to work stripping the leaves from the creeping thistles, allowing the Exmoor ponies and deer access to the juicy heads. Then ants cut the stalks into lengths before covering their nests with them. Soon the plague was vanquished.

  The purple emperor butterfly is one of Britain’s rarest and most beautiful. Long thought to be a denizen of deep woodlands, it had never been seen at Knepp until 2009, when a butterfly expert saw one flying among young willow scrub in the southern portion of the estate. The habits of the emperor, incidentally, leave much to be desired. They feed on the juices of rotting carcasses and fruit, or on excrement. Among butterfly aficionados it is known that Big Cock shrimp paste is a surefire lure. By 2015 over 126 emperors were seen in a single day over Knepp. Their presence astonished the experts, for they were flying over regrowing willows rather than long-undisturbed forest. It seems that scientists have misunderstood the species’ preferred habitat: it had been forced to seek refuge in dense forest after willows declined owing to changes in land use over the past century.