Editorial 1 : An overlooked molecule could solve the Venus water mystery
Introduction
More than four billion years ago, Venus had enough water to cover its surface with an ocean 3 km deep. Today, the planet only has enough for this ocean to be 3 cm deep.
Following the water trail
- There are two reasons why Venus lost its water. The first is its hellish atmosphere — a result of its carbon dioxide-rich composition, which causes a strong greenhouse effect. The planet’s surface is hotter than water’s boiling point, simmering at 450 degrees C. So water can only exist as vapour in Venus’ atmosphere.
- Second, water was a victim of the planet’s proximity to the Sun. The Sun’s heat and ultraviolet radiation combined to shred water molecules into their constituent hydrogen and oxygen atoms in Venus’s ionosphere — the upper region of the atmosphere, where charged atoms, molecules, and their electrons zoom around at high speeds.
- The two theories broadly blame thermal and non-thermal processes for the water loss.
- The thermal process refers to hydrodynamic escape. As the Sun heated Venus’s outer atmosphere, it expanded, allowing hydrogen gas to leak to space. This escape lasted until the outer atmosphere sufficiently cooled, by about 2.5 billion years ago.
- Via the non-thermal process, they focused on hydrogen atoms escaping Venus to space. Water levels drop as a result because the oxygen atoms left behind have fewer hydrogen atoms with which to form water.
The key findings
- Scientists first encountered the formyl cation (HCO+) — a positively charged molecule.
- Scientists have known for a while that HCO+ molecules drive hydrogen escape on Mars.
- According to Scientists, the Venusian and the Martian upper atmospheres are similar, so she and her colleagues decided to model the same underlying reactions in Venus’ ionosphere.
- On Venus, the team found that a particular reaction, called the HCO+ dissociative recombination reaction (DR) occurs in bulk at an altitude of about 125 km, above the clouds made of sulphuric acid.
- HCO+ is created when a carbon monoxide molecule (CO) loses an electron while absorbing an hydrogen atom.
- DR is the reverse reaction: HCO+ absorbs an electron and breaks up into CO and an hydrogen atom. These energetic hydrogen atoms then escape into space.
- The team built models to simulate the influence of this reaction on the upper atmosphere, and found that it accelerated water decline once the hydrodynamic escape of hydrogen gas ended.
- Specifically, the researchers found HCO+ DR could have doubled the rate at which Venus lost water by hydrogen escape.
- This means if Venus had oceans in the past, they could have lasted longer than expected — because the faster rate of hydrogen escape means the planet could have lost more water in the same amount of time.
- Further, the model predicted that the amount of water on Venus would have stayed roughly the same from nearly 2 billion years ago. This is because, as a non-thermal process, the HCO+ DR reaction would’ve gone on indefinitely and drained all the water.
- Yet Venus still has some water today.
The missing molecule
- However, we have no proof that HCO+ ions existed in Venus’s atmosphere in the first place — let alone proof that they participated in the HCO+ DR process.
- The authors wrote in their paper that past space missions had neglected looking for HCO+ ions, and that orbiters sent to Venus couldn’t decipher the chemical signatures of HCO+ DR from afar.
- Scientists are working on future Venus missions to look for HCO+ in the planet’s upper atmosphere.
- NASA’s MAVEN mission to Mars as an example of a mission dedicated to probing the upper atmosphere.
Conclusion
The fact that Venus is [100,000-times] drier than the earth is an anomaly that deserves an explanation. The questions like “Is Venus abnormally dry? Is the earth abnormally wet?” are helping scientists to dig deeper to know the reasons behind.
Editorial 2 : India-China consumption comparison
Introduction
In 2023, India surpassed China to become the world’s most populous country. The development came against the backdrop of a declining birth rate (6.4 births per 1,000 people) and total fertility rate (~1%) in China. A cross-comparison also assumes significance owing to the contrasting experiences of the two countries in their respective geopolitical landscapes.
How do the numbers compare?
- Both India and China have a large consumer base. A consumer is anyone who spends more than $12 a day, as per the Purchasing Power Parity [PPP], 2017.
- Private Final Consumption Expenditure (PFCE), which measures total consumption expenditure by households and non-profit institutions serving households on goods and services, serves as a useful proxy for consumer spending especially as income and consumption are concentrated within the consumer classes.
- The data reveals that as a percentage of GDP, India spends significantly more on consumption than China.
- While PFCE contributes more than 58% to India’s GDP currently, it contributes only 38% to China’s economy.
- Additionally, the final consumption, which also includes government consumption expenditure, constitutes 68% of the GDP for India and 53% for China.
- This implies that the government is a much bigger consumer in China than in India. Furthermore, while the percentage for India is steadily increasing, the same for China has been on a decline.
- The aggregate data on PFCE reveals that despite China’s economy being approximately five times bigger than that of India’s, its PFCE amounts to relatively a lot less, only about 3.5 times that of India’s.
- This not only means that consumption is a much larger contributor to India’s GDP, but that India will equal China’s consumption level at a relatively much lower GDP (~$10 trillion) as against China, which achieved the scale at approximately $17 trillion.
- Secondly, despite the gloomy narrative around China’s consumption, its PFCE has registered a significant increase in the past four years. Its PFCE remained rather constant in 2020 (pandemic year) before registering a huge uptick in 2021.
- On the other hand, India’s figures have steadily increased from $1.64 trillion in 2018 to $2.10 trillion in 2022.
- Thirdly, in 2022, while China recorded a decline in its numbers — both aggregate and per-capita - India witnessed marginal growth in both categories.
- Finally, in terms of ratio, India’s PFCE has closed the gap with China from ~3.3 to ~3.1. The significance of India closing the gap in terms of ratio here needs to be underlined.
- To beat China in terms of ratio would have required India to grow at a significantly higher rate than China, which it did. In terms of per capita PFCE, while the values mirror aggregate numbers, there is one exception.
The comparison
- Comparing the nominal PFCE numbers alone could sometimes lead to a distortion. This is because the nominal figures do not take into account the discrepancies between the cost of living that might exist.
- Consumption is not just about consumed value but also consumed volume. And nominal figures only give an idea of total consumption value — might not give an idea of the volume of goods and services consumed.
- Thus, to account for consumption by value, a comparison of PPP figures becomes imperative.
- On comparing the PPP numbers, the gap between the consumption expenditure further closes down. In PPP terms, China’s PFCE is approximately 1.5 times that of India.
- On the other hand, India added a trillion dollars to its consumption expenditure (PPP) in 2022 despite a worsening exchange rate.
Expenditure by categories
- India’s consumption expenditure is characterised by higher spending on food, clothing, footwear, and transport and low spending on education, culture, recreation, and healthcare — typical of an underdeveloped or developing market.
- China’s consumption basket, on the other hand, represents a relatively developed market. Even as food and beverages constitute the biggest chunk of China’s consumption, it is declining as a percentage of its total consumption expenditure — a sign of a maturing market.
- Additionally, it spends a substantially higher percentage of its expenditure on housing, white goods, recreation, education, and healthcare than India
- To put things in context, in advanced economies like the U.S., Japan, EU, Germany and the U.K., expenditure on food isn’t the highest bracket.
Conclusion
- In aggregate terms, India spends around half of what China spends on food, transport and communication, and clothing and footwear. Whether India’s consumer class with increased spending enhances its appeal to foreign businesses as a preferred destination over its competitors amidst the China+1 narrative remains to be seen.