Editorial 1 : This century, heatwaves are moving slower and lasting longer
Context
India has increasingly been in the grip of more frequent and intense heat waves, with outdoor workers especially struggling with the rising mercury. A recent study published in Science Advances showed that it wasn’t just India: the whole world is grappling with slower and longer heatwaves.
Temperature and circulation
- Heatwaves have a terrible impact on human and animal life, with increased risk of wildfires, damaged crops, and worse health.
- Analysing temperatures around the world from 1979 to 2020, scientists found that on average, heatwaves have slowed down nearly 8 km/day each decade and lasted longer by about four days — the effects being particularly drastic in North America and Eurasia.
- Heatwaves have also increased in frequency, from about 75 events averaged over 1979-1983 to about 98 over 2016-2020.
- In thinking about heatwaves and how they would change in the future, there are two pieces of the puzzle that climate scientists think about.
- One of them is thermodynamics: it’s just about the temperature. As temperatures are getting warmer, heatwaves are going to get warmer. The second piece is the dynamics: the atmospheric circulation patterns that cause heatwaves.”
The heat moves
- Previous studies have mostly focused on how frequent heatwaves are or how hot it gets during one.
- In this study, the researchers classified contiguous heatwaves as events with extremely high temperatures, covering more than a million square kilometres, and lasting for longer than three days.
- They then tracked the movement of these huge masses of hot air over space and time, studying how far and how fast they were moving – one of the first groups of scientists to do so.
- Instead of just focusing on the frequency and the intensity of heatwaves, the study also checked how fast they were propagating and how long they lasted.
The guiding hand falters
- But what could be causing them to move so sluggish? The scientists analysed the upper atmosphere’s air circulation patterns, to see how the moving air could affect these big blobs of heat.
- They found that over the years, the jet stream — a fast, narrow current of air that flows from west to east high up in the troposphere — has become weaker.
- The jet stream guides atmospheric waves, waves that are caused by the earth’s rotation and which influence the earth’s surface temperature.
- As the jet stream weakens, these waves also move more slowly, leading to more persistent weather events, and more spells of high and slow-moving heat.
- Scientists found that though natural climate variability and natural events also influenced how heatwaves had changed, human activity and greenhouse gas emissions have played a dominant role in rendering the slower-moving and longer-lasting heat.
Way forward
- In densely populated urban areas, some strategies to better mitigate changes in heatwaves would be to plant more trees and increase green infrastructure – an undertaking
- Adding to the already long list of studies, like how the intensity of hurricanes has increased or how there is extreme precipitation, this study, is another signal of how climate change could influence our daily lives, our health, our environment — by changing the behaviour of heatwaves.
Editorial 2 : What is the current status with respect to spice exports?
Context
Last month, Hong Kong and Singapore recalled certain spice mix products of the MDH and Everest Group allegedly over the presence of a higher than prescribed level of the sterilising agent Ethylene Oxide (ETO). The Indian authorities have now initiated several measures to ensure that Indian spices comply with food safety standards of the importing countries.
The occurrence of contamination
- India does not use ETO as a pesticide but only as a sterilising agent to reduce microbial load in finished (spice) goods.
- Most of the agro products, including spices, are heaped in mandies (auction yards for farmers) where they are contaminated by human, bird, reptile and insect contact.
- Many of the large factories receive material from the mandies, which is then fed on automated lines.
- It leaves them with high microbial levels and forces them to opt for ETO sterilisation. However, the contamination levels can be reduced early through the processes adopted for value addition.
Indian spice exports
- In 2023-2024, India exported spices worth $4.4 billion (nearly 14 lakh tonnes), which is 12.3% higher than the financial year 2022-2023.
- Data shared by the United Planters Association of Southern India reveals that chilli, spice oils and oleoresins, curry powder and paste, cumin, mint products, cardamom and pepper are some of the largest exported spices and spice products in the financial year 2022-2023.
- In terms of production, garlic, ginger and chilli were the top three spices produced in FY23.
- China, Bangladesh, west Asian countries and the U.S. are important markets for Indian spices.
The impact of the recall
- An office bearer of the Federation of Indian Spice Stakeholders pointed out that Singapore and Hong Kong had not banned the Indian products, but only recalled them.
- Exports have resumed to these countries and hence there may not be much impact in the coming months because of this issue. India’s share in total spice production globally is about 70%.
- Countries have different standards for ETO and maximum (pesticide) residue levels (MRL). The European Union has stringent norms for both ETO and MRLs while Japan largely sources only organic products.
- A section of chilli growers in Telangana said the issue is not likely to affect farmers much as most of them do not export directly.
- Further, Indian food exports have faced several challenges in the past too because of stringent norms of the buying countries.
- A planter pointed out that cardamom and black pepper are cultivated as inter crops with tea, coffee or rubber. The MRL is stringent for these main crops and hence the two spices are able to meet the norms.
- Manufacturers of spice mixes and pastes should look at sourcing genuine Indian grown spices rather than using imported spices.
- Further, they should be cautious when they import spices from other countries and export value added products.
- However ETO is permitted by the U.S., the EU seeks steaming as the method for sterilisation. But while the cost of using ETO as a sterilising agent is ₹5 per kg, for steaming it is ₹20-₹25 a kg.
- The Indian government should lay down achievable guidelines and tell the buying countries about it.
Conclusion
Following the recall by Hong Kong and Singapore, the Spices Board issued a detailed protocol to all manufacturing exporters to prevent ETO contamination. The Board also said it was starting mandatory testing of spice consignments to Singapore and Hong Kong for ETO. It has also taken up with the international food standards body the need for ETO usage limit as it varies for each country.