Earth Day 2022

Counterculture or moon shots? Rachel Carson or James Lovelock? What prompted U Thant, the Secretary General of the UN in 1969, to sign the declaration to bring about an annual Earth Day? The first one was celebrated in 1970, the Paris Climate Treaty was signed on another. Now in a year that has seen record breaking heat waves simultaneously at both poles (40 Celsius above normal in Antarctica, 30 Celsius above in the Arctic) in a week in early March, and a heat wave in April covering south east, south, and central Asia, Earth Day has come around again. All tipping points are long past, now it is a matter of survival.

The risk of Armageddon has risen dramatically. Stay bullish on stocks over a 12-month horizon.

Attributed to BCA Research in a tweet

We have known for quite a while that climate changes in the past couple of million years drove the evolution of the genus Homo. A brilliant new paper gathers archaeological and computational evidence that Homo sapiens arose in a climate change event 300-400 thousand years ago. If we are the product of a climate change, it stands to reason that large changes in the global climate can drive us into extinction, or at least into a population crash. If the weather is not the end of us, it could be the end of civilization. Quite a storm? Place a buy order with your broker. Better still, read some books or listen to an interesting lecture. Some suggestions follow.

Grasslands of India by Jayashree Ratnam (on Youtube)

Yesterday I listened to Ratnam’s talk about the unrecognized savannas of India. She gave a very clear definition: if the tree canopy is not continuous, then it is a savanna. The sunlight percolating to the ground allows lots of ground layer plants to grow. As a result, the competition to reach the sun does not drive the ecology, and it is totally different from a forest with a canopy. Whenever I’ve traveled in the last couple of years I’ve come across a savanna mis-classified as a degraded forest. As a result of this colonial-era mistake these habitats are being destroyed and species which need such a habitat are now endangered: the black buck, the Indian elephant, the great Indian bustard, the Bengal Florican. Ratnam gave a wonderful account of the under-counting of biodiversity in such biomes. She went on to talk about the cost of this mistake in climate mitigation efforts. Large scale tree planting in these biomes kill the undergrowth and release soil carbon into the atmosphere which is not compensated by the trees. The discussion at the end was specially interesting.

A take-away lesson: by merely re-focusing on highly modified ecologies like cities, roads, their verges and those of farmlands, the very large economy that has been built around carbon-neutrality can work without endangering grassland species.

Otherlands by Thomas Halliday (Penguin)

Traveling across the planet can give us a view of the enormous variety of life that shares this current climate with us. But they are mostly limited to what grows in this current range of temperatures, humidity, or oxygen and CO₂ in the atmosphere. Halliday then takes us on a tour of what kinds of biomes the earth supported in vastly different eras. The billion year journey is illuminating: our current crisis is not a crisis for the earth, it is for our own survival. A changed climate will support different animals and different plants.

A take-away lesson: the earth endures, species don’t.

A Natural History of the Future by Rob Dunn (Hachette)

If you live in a city you might have noticed the life around you. Not just the gardens full of roses, other colourful flowers, and the weeds, the songbirds, pigeons, and crows, dogs and rats and their individual fleas, the mosquitos, flies, and the cockroaches, but also the lichens and mosses that grown on concrete, SARS-CoV-2, and other diseases, all live in an ecology we have created. Dunn writes about how the human-modified environment drives evolution. One of the interesting chapters in the book looks at the particular ecological niche that we humans occupy. Interestingly, most humans continue to occupy this niche even today. Across the globe today, and in recorded history, less ideal climates, or extreme climate variability, generally contribute to a fall in GDP and an increase in violent crime.

A take-away lesson: free movement is essential for the survival of species as the climate changes; so one needs to create green corridors joining different biospheres. It is an interesting political exercise to think that the same lesson also holds for humans.

Golden flowers fill your eyes

Green and gold caught my eyes as we drove in the damp heat of the early afternoon through Manas National Park. It may be early spring in astronomical terms, with the days still getting longer, but as seasons are counted in these eastern foothills of Assam, it was high summer. Monsoon was less than a month away. Most trees had already shed their spring leaves, and had begun to flower. But was this the flower of the tree?

I had to tear my eyes away from the lovely flowers to take in a larger picture. Did the leaves and flower actually grow from the tree? They were carried on rather thin woody stalks. But would such thin stalks ever grow directly from the main trunk of a tree? Normally a trunk branches multiple times before you come to leaf-bearing or flower-bearing stalks.

Pull back a little further. It becomes clearer. No the flowers do not belong to the tree. It is a silk cotton tree (Ceiba pentandra, earlier Bombax ceiba). In this place it is late in its flowering season. Some of the smaller trees are still flowering, some are fruiting, some are still releasing their lovely silky parachutes into the air, but giants like this are past all that and are already prepared for the monsoon. The flowers are orchids growing over the tree. A little search, and you find that they are golden-flowered dendrobium (Dendrobium chrysanthum). Orchids are said not to harm the trees they grow on. They have green leaves, so they produce their own sugars. Their roots are said to penetrate only the bark of the tree. It is said that they don’t tap into the wood. I wonder then where they get water from? Roots of plants which grow into soil search widely for water. It seems that orchids specialize in pulling moisture from the air.

I pull back further. The whole jungle is full of trees carrying various kinds of orchids. Many are flowering. Something clicks into place. I’ve seen flowering orchids in the Himalayas during winter, when it often rains. Now, here in the plains below the mountains, I see them just before the monsoon. They flower when the air is damp. Most plants require a lot of stored sugar and water for their flowers and fruits. That’s what is happening here, in this hot damp place. The flowers will fruit and produce their wind-borne seeds at about the time the monsoon winds begin to blow. On this vast scale, I begin to admire the small orchids, the large trees, and the vast jungle and the climate they are in. They shape each other.

The battle of the sexes

You can tell that I’m a pretty amateurish birdwatcher because I can’t yet look at a bird in passing and ask “Which wheatear was that?” I have to look carefully at birds like this before I can say that it is a desert wheatear (Oenanthe deserti). Then I have to look carefully again and again at the quite differently coloured bird below, and ask The Family “Is that a female of the desert wheatear?” That’s why I’m quite in awe of the great field ornithologists like Salim Ali and Evigeniy Panov who could reputedly identify birds that flew across the periphery of their vision.

Entirely through behaviour and ecology, Panov argued that the blackstarts (genus Cercomela) and wheatears (genus Oenanthe) are related. Along broad lines his hypothesis was proven correct by molecular methods, although he continues to dispute the details. Genetic studies depend a lot on which genes are sampled, and a true picture emerges only when many genes are studied together, and Panov may perhaps yet turn out to be correct even in some of the smaller details. In any case, his observations seem to be driving much of the more recent work on the evolution of chats and wheatears.

The female is hard to spot. Panov tells us why this should be expected. Desert wheatears are opportunistic nesters. They nest in the mouths of holes dug by rats and Jirds when possible, in any other cover which is available, and even in open ground if no cover can be found. The female incubates the egg entirely without help from the male. Since this can be entirely exposed, it is useful to have colours which help her to fade into the background. Even in the photo above, she does not stand out. Before you mentally label the father as an useless pig, remember that mammalian mothers have to incubate their fertilized eggs with absolutely no help from fathers. At least some species among our theropod dinosaur cousins, the birds, have distributed the job better. I’ve learnt one trick from Panov for distinguishing it from the female of the Isabelline wheatear: look for a rapidly wagging tail with changes in rhythm.

Disturbances and consequences

Like any normal wildlife tourist, I’m happy to see a new place, take some photos, talk about the trip with friends and family, and then forget about it. Writing a blog made a difference, because it made me look again at the photos and think about them. After seeing the beautiful but arid grassland of Tal Chhapar with its utter lack of predators, I began to wonder whether it is a self-sustaining ecology. If it were not for human care, wouldn’t the place soon be overrun by deer which eat up all the vegetation and reduce it to an arid desert? Have the old Maharajas and their unsustainable love of shooting tigers and cheetahs spelt the doom of their beloved hunting ground?

I wondered idly about this question, until, on the flight home, I read about a method that naturalists use to study the ecology of ancient terrains where mammals first began to radiate into new forms. This method of drawing cenograms turned out to be easy. The simplest of all would be to list, for example, all the herbivorous mammals in Tal Chappar, rank them by their size, and plot the average weight of each species against the rank. This method was apparently first used by Legendre in 1986.

I was pretty sure I’d seen all the herbivores in Tal Chhapar. The Nilgai (Boselaphus tragocamelus) was definitely the largest, followed by wild boars (Sus scrofa), black bucks (Antilope cervicapra), and Chinkara (Gazella bennettii), in that order. I’d also seen a few black naped hare (Lepus nigricollis). A checklist from the Zoological survey assured me that I’d only missed the three smallest: gerbil (Tatera Indica), palm squirrels (Funambulus pennantii), and desert Jirds (Meriones hurrianae). A quick search gave me their average weights. The only surprise was that the hares weighed more than 2 Kgs in mean. You can see the resulting cenogram above. There are no species with weights between a couple of hundred grams and a couple of kilos, allowing a clear division between small and large mammals. Apparently this is common in almost all ecologies where migration is possible, but the reason is not clear to me. The nearly horizontal line which connects the small mammals is said to be characteristic of hot climates (in cold climates this line would slope down more steeply). All very nice, but I couldn’t use this to say anything about whether the grassland ecology I saw was stable or not.

Fortunately, there is a method for helping you think about that. It was developed by Valverde in 1964. You start by drawing another cenogram from the mammalian carnivores. I’d seen a desert cat (Felis lybica, photo above), a white-footed fox (Vulpes vulpes pusilla), and a grey mongoose (Urva edwardsii). I’d also seen pelts of tigers (Panthera tigris) and Asian cheetahs (Acinonyx jubatus) hunted to extinction from these grounds in the Maharaja’s palace in Bikaner. The checklist told me that I’d missed seeing Golden jackals (Canis aureus) and jungle cats (Felis chaus). Newspaper reports also told me that I should add stray dogs to this list, because they are responsible for large numbers of attacks on deer in this place.

Valverde tells us to put the two cenograms on one figure, and draw lines which join each predators with its prey. You can see that one half of the figure (the part in yellow) is full of criss-crossing lines joining predators and prey. This strong food web is likely to keep this part of the ecology in balance, even if one of the species goes extinct. The remainder of the food web (the part in pink) seems to have been altogether more sparse. The two extinct cats used to feed larely on three herbivores: Nilgai, wild boars and black buck. With the extinction of the tiger and the cheetah, a niche in the ecology was vacant. Stray dogs have moved into it, replacing the cheetah as the sole predator on black buck. Although there is a lot of consternation about it, perhaps it is the reason this ecosystem has not collapsed yet. There is space yet for a larger predator, but nothing apart from humans has appeared here.

Two species of herbivores are currently unchecked by predators. I suppose a census would tell us that Nilgai numbers have increased over the last hundred years. But in this arid land, the lack of food would perhaps always have been a major limitation on this species. This scarcity is now the only thing keeping Nilgai numbers in check. The wild boars are more problematic I think. In many parts of India where tigers have disappeared, wild boar are in constant warfare with farmers. I recalled meeting farmers keeping vigil on their fields in Maharashtra, to prevent wild boars from raiding their fields (photo above). Perhaps dogs will eventually check their numbers by preying on the squeakers, but if they don’t then conflict is inevitable. Instead of decrying the role of feral dogs in this ecology, we should be happy that they have moved into this food web and begun to stabilize what humans had nearly destroyed.

Water world

A few winters ago, I spent a week in one of the smaller islands of the Andaman archipelago. Some mornings I could walk most of the way around the island, at the edge where land and sea meet. The green wall of trees on one side would loom over the mysterious blue depths on the other. Our world is a water world; almost three quarters of its surface is ocean, over half the life on earth is oceanic. What do we know about it?

A recent read (partly hidden behind a paywall) overturned everything that I though I knew about the earth. It seems that plants make up less than 10% of the biomass of the oceans (they make up 95% of the biomass on land). The waters of our world are dominated by animals, bacteria, and complex single-celled creatures collectively called protists. These three groups make up 80% of the biomass of the oceans (on land, these groups make up 2% of the biomass). In the oceans fast growing primary producers make up about 15% of the biomass, whereas consumers, with a slow lifecycle, make up the rest. There are two different worlds sharing this planet of ours!

Entering the desert

It is late afternoon. A short detour from the highway over a bumpy stretch of land, and suddenly we are in the desert. The Little Rann of Kutch seems to be a perfectly flat landscape. I’m lost instantly. There was no landmark that I can see, but the drivers of jeeps here seem to find their way as if on signposted highways.

There must be ways of seeing. This is not barren land, there is life here. Over the next two days I’ll begin to understand its signs. There are clumps of hardy bushes, sometimes even trees. There are insects, birds which eat the insects, and birds which eat the birds which eat insects. There are lizards, jackals, and wild ass. There are scorpions and snakes. Sometimes I can see water in the distance; I will have to learn the difference between a mirage and the water. This is not too hard, it turns out. It is much harder to understand how the drivers navigate.

Now and then there is a hillock. Man made? We come across one near sunset. An imperial eagle rests on top of it. There is dry grass at the base of the hillock, and a white patch, clearly visible even in this failing light. Salt left by evaporated water. The Rann of Kutch lies below sea level, and covered with a sheet of water when the tide is sufficiently high. When the sea level rises this land will be the first to drown.

After the sun goes down the jeep drives around to the east, where there is a thin sheet of water between us and the hillock. The ground must be wetter here than in other places, because there is almost a forest of bushes. I wonder whether the water is permanent. Probably not; there are tyre tracks pointing into the water. Those must have been made when this area was dry. This is a wonderful angle to take a photo from. I’ve never lost cell phone connectivity through the day, so I could share the journey with The Family. Now I send her the last photo of the day.

A dead white man

Statue of G. A. Carver Marsh (b 13 Aug 1862, d 1st Feb 1934)

Dead white men, dead white males, or dead white
European males (DWEM) are the famous deceased
European males that are often the focus of
academic studies of history and Western culture.
(Wikipedia)

Nilgiri teas are the least aromatic of the Indian teas. On our trip to Valparai I kept coming across the various ways in which the plantations which grow this insipid leaf had devastated the rain-forests of the Nilgiris. We stayed in a bungalow built for the manager of one of these estates, so I keep my complaints a little muted.

But as we left Valparai and began on the 40 hairpin bends which cross the Anamallais, The Family spotted a viewpoint with this statue. Had we found the culprit: the man responsible for this ecological devastation, the Hitler of the hills? The inscription at the base of the statue identified the man as G. A. Carver Marsh. Clearly famous in his lifetime, his memory is slowly fading. I am unable to find his full name. And of the many things he must have been known for in his lifetime, I can only find the following reference in the book Madras Miscelleny by Muthaiah S., “The Anamallais may have been opened up by G. A. Carver Marsh, perhaps the only pioneering planter remembered in South India by a statue (at a road bend near his Paralai estate) but it was three planters from Ceylon, E. J. Martin, O. A. Bannantine and Unwin Maclure, who first planted tea there”.

Such is fame. All the blame I was laying on this dead man must now be redistributed. When you dig deeper, you see that coffee plantations predated tea in this region. So perhaps the blame gets diluted further.

Even such a clear case of devastation cannot be traced back cleanly to a single original cause. The best one can say now it that it was the economics of a mercantile empire which destroyed this region. What then is Mr. Carver Marsh to be remembered for?