Science

En-ROADS to Efficiency

We saw En-ROADS last time as a tool to simulate the impact of steps we can/should to en route to a decarbonised future. Now, we simulate scenarios, starting with energy efficiency.

The silver bullet?

There is a reason to start with this. A lot of people (policymakers) think energy efficiency offers huge opportunities in the journey of decarbonisation, and it comes at zero cost (or even at negative cost)! I suspect the famous McKinsey curve has something to do with this belief. I suspect the famous McKinsey curve has something to do with this belief. But let’s test the hypothesis.

Simulation results

First, the baseline: we have seen before that if we maintain the status quo, we end up with a temperature rise of +3.6 oC compared to the pre-industrialised levels. We do run the model in two steps. First, we make set maximum efficiency changes (transport and building) at the current volume of electrification, i.e. no growth.

The underlying assumptions for this simulation are a growth rate of 5% per year from 2023 and a 5% rate for buildings and industries (new and retrofitted).

Now, switch on electrification to the mix. Here we added 100% electrification of new transport (rail and road) and buildings from 2023, which we know, can not be true!

So, what are we seeing? Even at extremely optimistic rates of energy efficiency and electrification rates, we will miss the climate goal of 2100. Building electrification also causes an increase in energy costs in the medium term.

Ignoring building electrification still makes most of the results (+2.9 oC) at no cost. The question now is: here is an option (improving efficiency) that can still make a good stride towards decarbonised work at no cost, but not realised. From an economic standpoint, this doesn’t make sense – a market failure.

References

The Paris Agreement: UNFCCC

EN-ROADS: Climate Interactive

En-ROADS to Efficiency Read More »

En-ROADS to Climate Goal

Limiting “global warming to well below 2, preferably to 1.5 oC, compared to pre-industrial levels”, is the main objective of the Paris agreement, which is a legally binding international treaty on climate change. However formidable the goal might appear, there are pathways to achieve it with the help of deploying appropriate technologies and policies.

We introduce En-ROADS, the online climate simulation tool developed by Climate Interactive, Ventana Systems, UML Climate Change Initiative, and MIT Sloan, to create the results from various scenarios. The simulator provides a set of outputs, such as the temperature increase by 2100, CO2 emissions, cost of energy, sea level rise, and about 100 others from a selection of inputs that include 1) energy efficiency and electrification, 2) growth, 3) land use, 4) carbon capture technologies, and 5) Carbon pricing and other policies.

The screenshot of the interface provided below shows how the interactive lets the user handle some serious physics and math of climate change as child’s play and free of charge!

References

The Paris Agreement: UNFCCC

EN-ROADS: Climate Interactive

En-ROADS to Climate Goal Read More »

Loss and Damage and COP27

The 27th session of the Conference of the Parties (COP27) has just concluded this morning at the Sharm El-Sheikh (Egypt) Climate Change Conference with the signing of what’s proclaimed a landmark deal, the endorsement of the “loss and damage” fund.

Governments took the ground-breaking decision to establish new funding arrangements, as well as a dedicated fund, to assist developing countries in responding to loss and damage. Governments also agreed to establish a ‘transitional committee’ to make recommendations on how to operationalize both the new funding arrangements and the fund at COP28 next year. The first meeting of the transitional committee is expected to take place before the end of March 2023.

UN Climate Press Release:

From COP 19

“Acknowledging the contribution of adaptation and risk management strategies towards addressing loss and damage associated with climate change impacts”

FCCC/CP/2013/10/Add.1: Decision 2/CP.19

Although the term, loss and damage, came inside COP books in 2013 at the COP17 in Warsaw, Poland, the push for a suitable compensation mechanism supporting vulnerable countries to endure the cost of climate change, which is predominantly inflicted by a few industrialised countries, has a long history. As per Wiki, AOSIS proposed an insurance pool as early as 1991 when United Nations Framework Convention on Climate Change (UNFCCC) was in the process of setting up.

Reference

COP27: UNFCCC

COP19 Reports: UNFCCC

Loss and damage: Wiki

Loss and Damage and COP27 Read More »

Neanderthal mother and a Denisovan father

We have seen that the Neanderthals lived in Western Eurasia and Denisovans in Eastern Eurasia (basically, Denisova cave). The 2018 report by Slon et al. provides the DNA analysis of a bone, Denisova 11, that comes from an individual who had a Neanderthal mother and a Denisovan father!

The previous sequencing had established that the Neanderthals and Denosovals diverged from each other by about 390 kya. It is, therefore, fascinating to note what was found in the Denisova 11 sample. The mitochondrial (mt)DNA showed it was a Neanderthal type, and carbon dating said it was more than 50,000 years old. And what is more: 38.6% of its DNA fragments possessed alleles matching the Neanderthal genome, and 42.3% carried alleles matching the Denisovan genome!

Reference

The genome of the offspring of a Neanderthal mother and a Denisovan father, 2018, Nature, 113

Neanderthal mother and a Denisovan father Read More »

Post # 365: What Have We Learned in One Year?

We started with the equation of life, Bayes’ theorem, how it mimics the natural learning process, and how even experts can not escape the curse of the base rate fallacy.

We understood the law of large numbers but failed to notice that there was no law of small numbers and continued gambling, hoping to even out, leading to complete ruin.

We have learned mathematically that at the Roulette table, the house always wins, yet we spent countless minutes watching YouTube videos learning strategies to beat the wheel. We also watched financial analysts all day on TV, reasoning on hindsight and glorifying market-beating fund managers, forgetting they were just the survivors of Russian roulette. The same people continue to make us believe in momentum and hot hands.

People gamble and play the lottery, where they are guaranteed to lose, and fail to invest for their retirement, where they are guaranteed to win. Three-quarters of Americans believe in at least one phenomenon that defines the law of physics, including psychic healing (55 per cent), extrasensory perception (41 per cent), haunted houses (37 per cent), and ghosts (32 per cent).

Rationality, by Steven Pinker

We have seen how journalism can mesmerise readers by reporting an 86% increase in myocarditis for the vaccinated, a 300% increase in thrombosis over oral contraceptives, or an 18% risk of colorectal cancer by eating processed meat. We just became easy prey for our inability to make decisions based on risk-benefit trade-offs and the eternal confusion between absolute and relative risks.

We found how the world can make us believe in diseases with causes and designs with a purpose when events were nothing but random processes. We see how careless choice of words and phrases and incorrect teaching lead to myths about evolution.

Even in an era of open data, data science and data journalism, we still need basic statistical principles in order not to be misled by apparent patterns in the numbers.

The Art of Statistics: How to Learn from Data, by David Spiegelhalter

The author was referring to variabilities in the observed rates of events when the population is small, which is the concept behind funnel plots.

We understand that international trade is a win-win for both parties, yet we let free rein to populism and Brexit. We know that the Muslim community in India is on the fastest downhill in the fertility curve, yet we want to believe that the opposite is true and continue believing in one-child policies.

We also know that life is not a zero-sum game and that probability theory is not another useless thing you study in schools and forget later, but it is about how we make decisions and appreciate life. The understanding, or the lack of it, can be a choice between life and death, as we have just witnessed in the global pandemic.

Could everyone have a fact-based worldview one day? Big change is always difficult to imagine. But it is definitely possible, and I think it will happen, for two simple reasons. First: a fact-based worldview is more useful for navigating life, just like an accurate GPS is more useful for finding your way in the city. Second, and probably more important: a fact-based worldview is more comfortable.

Factfulness, by Hans Rosling with Anna Rosling Rönnlund and Ola Rosling

Post # 365: What Have We Learned in One Year? Read More »

The Denisovan Story

Another spectacle that emerged from Pääbo’s group was the discovery of Homo Denisovans from a bone sample excavated in Denisova Cave in southern Siberia. They possess the type of hominin mtDNA that shares a common ancestor with modern human and Neanderthal mtDNAs. And the stratigraphy of the location suggested the new samples lived at similar times to Neanderthals.

Where do they stand?

If we define the timelines as a function of pair-wise nucleotide differences of the complete mitochondrial DNA (mtDNA) from modern humans, Denisovans existed about 385 units away from humans. To put it in perspective: the modern humans are between 0 – 100, the Neanderthals at around 202 and the Chimpanzees at 1462.

Interbreeding

The researchers then searched for gene flow (interbreeding) similar to what was found with the Neanderthals using the five samples (San, Yoruba, Papua New Guinean, Han Chinese, and French) from modern humans. This time, there was no overlap between the French and the Han but found ca. 4% match with the Melanesian.

The new representation, combining the findings of the two studies (genome sequencing of Neanderthal and that of Denisovan), is presented below.

Reference: https://commons.wikimedia.org/w/index.php?curid=65505773

References

Krause et al., The complete mitochondrial DNA genome of an unknown hominin from southern Siberia, NATURE, 2010, 464, 894

Reich et al., Genetic history of an archaic hominin group from Denisova Cave in Siberia, NATURE, 2010, 468, 1053

The Denisovan Story Read More »

The Neandertal Affair

The contents of this post are based on Svante Pääbo’s 2010 paper titled “A Draft Sequence of the Neandertal Genome“, published in Science (Green et al., Science, 328, 710, 2010). The study reports genome sequencing of three samples collected from Neandertal bones from Vindija Cave in Croatia, and are carbon dated to be around 38,300 years old.

Based on the existing pieces of evidence, modern humans (Homo Sapiens) and Neandertals (Homo Neanderthalensis) diverged from the common ancestor (Homo Heidelbergensis) around 500,000 – 800,000 years ago. Here is a representation made by Dbachmann of the immediate ancestry of humans and taken from Wiki.

Reference: https://commons.wikimedia.org/w/index.php?curid=65505773#/media/File:Hominini_lineage.svg

The numbers on the Y-axis represent the past years in millions (mya). If you are wondering who appears on the two sub-branches of the branch, Pan, they are Chimpanzee (P. troglodytes) and Bonobo (P. paniscus)!

The earlier analysis of the mitochondrial DNA of Neanderthal, which was the subject of a publication in 1997, showed a lack of relationship between modern humans and Neandertals. That was insufficient to prove that interbreeding never happened, as other parts of genomes also need to be studied. If you are confused about what these are all about – a typical genome of a multicellular animal has two distinct parts: the nuclear genome and the mitochondrial genome. Most genomes (e.g., humans and other cellular life forms) are made of DNA (deoxyribonucleic acid).

The biggest challenge to confirming the interbreeding was the reason for similarities is the fact that these two have a common ancestor within the last million years. So a similarity between the two groups can be within the variability margins of homo sapiens themselves. To reemphasise the point: even if no interbreeding ever happened, the Neanderthals and Sapiens can still have similarities (e.g. humans and chimps have more than 90% similarities in their genomes).

The study compared the Neandertal genomes to five present-day humans: one each from San (Southern) Africa, Yoruba (West Africa), Papua New Guinean, Han Chinese, and French (Western Europe). To cut the long story, they found that the Neandertals are more closely related (by about 3-5%) to present-day non-Africans than to Africans, suggesting some form of interbreeding. The following graphic represents the findings.

Reference: https://commons.wikimedia.org/w/index.php?curid=65505773

Tailpiece

Most of the similarities and differences are academic. And society should not start equating them with friendship, relationships and identities. They are far more complex and, many times, socially constructed.

The Neandertal Affair Read More »

Svante Pääbo

The man who sequenced the first Neanderthal genome, the person who discovered a new type of human, the Denisovans, Svante Pääbo, is the winner of the Nobel prize in Physiology this year.

Let’s start with perhaps the most important one – the 1997 publication on the sequencing of mitochondrial DNA (mDNA). It established the presence of an extinct human, who was unlike the modern human. But in 2010, he sprung another surprise through genome sequencing and showed that there was, indeed, a gene flow from Neanderthal to modern non-African humans.

He’s not done yet! In the same year (2010), he published the mitochondrial DNA genome of an unknown hominin from southern Siberia, the Denisovans.

References

Krings et al., Cell, 90, 19–30, 1997
Green et al., Science, 328, 710, 2010
Krause et al., Nature, 464, 894, 2010

Svante Pääbo Read More »

Who Emits the Most?

We have seen that the global CO2 emissions in 2021 were about 39.4 gigatonnes. But how do different countries contribute to this? Hsiang and Hsiang report contributions from the top 15 countries in 2014. Here are the top 10 that I picked up.

CountryEmissions
(2014)
G tonne CO2		Cumulative
Emissions
(1751–2014)
G tonne CO2		Emission
per capita
(2014)
tonnes CO2
China10.3174.77.5
United States5.3375.916.2
India2.241.71.7
Russia1.7151.311.9
Japan1.253.59.6
Germany0.786.58.9
Iran0.614.88.3
Saudi Arabia0.612.019.5
South Korea0.614.011.7
Canada0.529.515.1

Notice that these ten already account for 75% of the total 34.1 Gt in 2014! Also to check is the disparity in the per capita contribution and the cumulative contribution that created this monster of climate change in the first place.

Hsiang and Hsiang, Journal of Economic Perspectives, 2018, 32(4), 3–32

Who Emits the Most? Read More »

The Nature in Natural Selection

We have seen before misconceptions about the theory of evolution still prevail due to generations of improper education. As a consequence, together with the existing cultural doctrines, the word nature got a superior stature as the ever-benevolent parent who can do nothing by love and care. So nature selects living organisms to something (perfection to some, purpose to another).

Let’s spend time and understand what is ‘nature’ in natural selection against the backdrop of evolution. What causes new species or the entities that survived?

Yes, nature is a killing machine. The species who endured it had differentiating features to accomplish the incredible. The species who prevailed can’t see the horror, but a hypothetical alien sitting outside the earth can vividly see the extinction of millions in favour of the hundreds.

The Nature in Natural Selection Read More »