The future of transport is electric (GS Paper 3, Science and Technology)
Context:
- With the planet needing to rapidly decarbonise to reach net zero targets, electric vehicles are seen as a key part of the transport solution.
- But the problem is how to accelerate EV uptake and implement complementary strategies to encourage people to shift to greener travel options.
Emissions from transport:
- The greenhouse gas emissions from transport are growing, having increased nearly 56 percent since 1990 at an average annual rate of 1.7 percent. This represents the highest emissions growth of any sector of the economy.
- Around 74.5 percent of all transport emissions are generated from road vehicles including cars, vans, buses and trucks.
Government policies:
- Much can be learnt from government policies that have played a major role in removing barriers to adoption in the world's top three EV markets; China, Europe and the US which collectively accounted for around 90 percent of all EV sales in 2022.
- Governments that provided people with financial incentives to buy EVs have been able to achieve a substantial shift in consumer sentiment towards greener car purchases.
- These incentives were designed to reduce the purchase price gap between electric and conventional vehicles and have mainly taken the form of vehicle purchase subsidies or rebates or registration tax discounts.
- Examples include the incentive schemes implemented in Norway since the 1990s, the US since 2008 and China since 2009.
Incentive programmes:
- EV drivers in Norway pay lower road tolls, gain access to bus lanes and benefit from cheaper and, in the past, free ferry crossings and public parking. People living in apartments have 'charging rights' safeguarded by government legislation.
- This all helped to increase EV sales to 50 percent market share in 2020, and 79 percent by 2022. No other nation comes close.
- France provides targeted incentives for people on lower incomes to purchase EVs.
- Individuals with annual income up to €14,089 are eligible to receive a bonus of up to €7,000 on the purchase of a new EV, while those above this threshold receive a maximum subsidy of €5,000.
- The subsidy is also capped at a maximum rate not exceeding 27 percent of the vehicle's gross purchase price.
- In the European Union, 21 of 27 member countries levied car taxes partially or totally based on carbon dioxide emissions in 2022.
- Ireland first introduced an emissions-based car taxation policy in 2008. An analysis of its impacts found it produced a cumulative carbon dioxide savings of 1.6 million tonnes from 2008 to 2018.
Feebate system:
- Feebates involve placing a levy on purchases of vehicles with high emissions and using the revenues to provide rebates for purchases of vehicles with zero or low emissions to offset their higher prices. Examples include France's Bonus-Malus and New Zealand's Clean Car Discount.
- If developed carefully, these systems can be a cost-neutral method of discouraging purchases of high-emission vehicles and encouraging purchases of EVs.
Phase-out of internal combustion engine:
- Any credible EV strategy also could consider EV mandates and the phase out of internal combustion engine vehicles.
- More than 35 countries have already announced plans for either full electrified sales, full electrified stocks or full phase-out of internal combustion engine vehicles over the next 10 to 30 years.
- The EU had planned to ban the sale of internal combustion engine cars from 2035.
- In February 2023, the European Parliament approved the ban, which was later revised to allow some combustion engines running on e-fuels to be sold beyond 2035. Still, this remains one of the world's strongest measures to phase out fossil fuel vehicles.
- Examples include the fuel tax credit scheme in Australia.
- This scheme has been criticised for subsidising the consumption of fossil fuels, particularly in the mining industry, and for providing direct benefits for high-polluting heavy diesel vehicles over 4.5 tonnes.
Mandatory fuel efficiency standards:
- Countries with high EV adoption rates have also backed up their transport decarbonisation strategies with robust fuel efficiency standards.
- These standards aim to limit vehicle emissions by mandating a maximum annual average level of carbon emissions across a car company's overall new car sales.
- Penalties are imposed on car manufacturers if these maximum levels are exceeded, which encourages them to offer low and zero emissions vehicles in markets that enforce these standards.
- Properly devised standards also reduce the cap over time until all new vehicles sold become zero emissions.
- Strong fuel efficiency standards already cover more than 85 percent of the international market.
- In recent times, some countries have proposed to tighten these standards further. Examples include plans by the US to introduce strict new emissions limits that would require two-thirds of vehicles sold in the US to be electric by 2032.
- The proposal, if ratified, will represent the most aggressive vehicle emissions reduction plan in the US and will deliver an average 13 percent annual pollution cut.
Deployment of EV charging infrastructure:
- The International Council on Clean Transportation is recommending policies to accelerate the deployment of EV charging infrastructure, including binding installation targets aligned with the expected growth in EVs and incentives to address charging gaps.
- It estimates more than 100 million chargers will be needed across its members' jurisdictions by 2030. But as of mid-2022, only 13 percent of these public chargers were in place.
- Having readily accessible chargers helps reduce concerns about range anxiety, which in turn can help improve EV uptake rates. It also reduces the requirement for EVs to have larger batteries which makes them more affordable.
Way Forward:
- Without a comprehensive set of consistent policies, particularly in nations embarking on their decarbonisation efforts, dependence on fossil fuels will deepen and reaching emissions reduction goals will become harder.
Chimaeras hosts to multiple genotypes, and maybe human organs
(GS Paper 3, Science and Technology)
Context:
- At present, more than 3 lakh people are waiting for an organ transplant in India alone; the global number is far higher, with no respite in sight.
- There is an alarming disparity in the number of organ donors and the number of recipients and animals have played an important part in filling this gap.
Chimaeras:
- The successful application of animal insulin and the more recent use of animal heart valves in human surgeries have saved human lives.
- Researchers have also made attempts to grow full human organs inside the bodies of animals using advancements in induced pluripotent stem cells (iPSCs) technology.
- At the same time, controversy continues to beset this field, most of it centred on the use of human iPSCs in animal embryos and the creation of chimeric animals, the results of which we are yet to fully comprehend.
Chimaeras in nature
- A genetic chimaera is a single organism composed of cells of more than one distinct genotype (or genetic makeup). The animal kingdom has several examples of varying degrees of chimerism.
- The half-sider budgerigar, a type of common parakeet widely adopted as pets, has different colours on either side of its body due to chimerism.
- The anglerfish displays an extreme degree of symbiotic chimerism in which the male fish fuses with and is eventually absorbed into the female fish, mixing their genetic makeups into a single animal.
- Marine sponges are known to have up to four distinct genotypes in a single organism.
Natural chimaeras among humans:
- They occur when the genetic material in one cell changes and gives rise to a clonal population of cells different from all the other cells.
- The fusion of two fertilised zygotes early in the embryonic stage can also lead to a condition in which two genetic makeups coexist in a single individual.
- Chimerism can also result from twin or multiple pregnancies evolving into a single foetus or a twin foetus being absorbed into a singleton.
- Researchers have also documented individuals living with two blood types. In fact, blood-group chimerism during multiple births is relatively common.
- Most chimaeras are detected during routine blood tests in hospitals or when family members undergo tests ahead of an organ transplant.
- Pregnant women have been known to harbour the genetic material of her foetus in the bloodstream during the pregnancy. (Such foetal DNA can be used to screen for genetic defects and congenital abnormalities using non-invasive prenatal testing.)
Microchimerism:
- Studies have also recorded a phenomenon called microchimerism, in which traces of the foetus’s genetic material are observed in mothers’ tissues many years after childbirth, resulting in two different genetic materials in a single person.
- Individuals undergoing treatments like bone marrow transplants usually have their bone marrow destroyed and replaced by that from a suitable donor.
- Since the donor’s bone marrow contains stem cells, they will produce blood cells that will subsequently repopulate the recipient’s blood-cell repertoire.
- Eventually, the recipient will have blood cells that resemble the donor’s and will be different from the genetic makeup of the recipient’s other tissues resulting in a chimeric individual.
- Solid organ transplants in humans are bound to produce individuals with two unique genetic makeups as well.
- The makeup of the donor’s organs will be significantly different from that of the recipient’s other tissues, also resulting in chimerism.
Chimaeras in non-human primates:
- Previously, chimaeras have been induced in laboratory settings, of rat-mouse, human-pig, and human-cow. These were in a bid to develop model systems that could ‘generate’ human organs of a suitable size, anatomy, and physiology.
- While rat-mouse chimerics had a near-normal lifespan, human-pig chimaeras had to be terminated in three to four weeks.
- While such studies have shown promise for growing organs destined for transplant, they are also limited by the fact that rats, mice, pigs and cows are evolutionarily distant from humans, and will pose biological and technical challenges when being used to grow human organs.
Live chimaera in non-human primates:
- In a recent landmark study, scientists reported the successful generation of a live chimaera in non-human primates. This is the first time scientists have succeeded in producing a live infant chimeric monkey.
- In studies with Cynomolgus monkeys, a.k.a. long-tailed macaques (Macaca fascicularis), researchers extracted embryonic stem cells from one-week-old embryos. They modified the DNA in these cells to include a green fluorescent protein (GFP).
- These GFP-marked embryonic stem cells were then injected into recipient embryos that were implanted into surrogate female monkeys, which delivered six full-term offspring.
- Using detectors, the researchers located the GFP signal in the tissues of one aborted male foetus and in one live-birth male. The latter signal originated from the donor cells that had been injected into the recipient’s embryo.
Outcome:
- The chimeric monkey had to be euthanised after ten days for health reasons.
- Extensive genome-sequencing investigations conducted with its cells showed a high degree of chimerism in its tissues, including eyes, fingernails, brain, heart, kidney, liver, gonads, and placenta.
Way Forward:
- As such, this study opens new doors for scientists to use non-human primates to create chimaeras that could become models for basic and translational biomedical applications in the near future.
