India’s Slowed Global Warming: Study
- Despite experiencing record-breaking temperatures and prolonged heat waves, India's average annual temperature increase sence 1901 is less than 0.7 degrees celsius, approximately half the global average. This according...
- The situation was discussed at a recent climate change conference in India, hosted by the Indian ministry of Habitat and Harvard University.
- Air pollution is a leading hypothesis for the relatively slow pace of warming.The Indo-Gangetic Plain, a densely populated region spanning northern India from Pakistan to Bangladesh, suffers from...
India’s Climate Puzzle: Why Is Warming Slower Than Global Average?
Table of Contents
Despite experiencing record-breaking temperatures and prolonged heat waves, India’s average annual temperature increase sence 1901 is less than 0.7 degrees celsius, approximately half the global average. This according to a study published in Science magazine. Scientists are still working to understand why India appears to be an exception to the global trend of accelerated climate change.
The situation was discussed at a recent climate change conference in India, hosted by the Indian ministry of Habitat and Harvard University. While the tropics generally warm at a slower pace than the poles, experts at the conference pointed to other potential factors contributing to India’s unique warming pattern, including air pollution and widespread irrigation.
Air Pollution‘s Role
Air pollution is a leading hypothesis for the relatively slow pace of warming.The Indo-Gangetic Plain, a densely populated region spanning northern India from Pakistan to Bangladesh, suffers from some of the world’s worst air quality. Industrial emissions,vehicle exhaust,dust,and agricultural fires contribute to a thick haze of atmospheric pollution. this includes aerosols that reflect sunlight,possibly cooling the region.
Globally,similar pollution is believed to have partially masked the full impact of greenhouse gas emissions throughout much of the 20th century.
However, this presents a dilemma for India. While air purification is desperately needed – pollution contributes to over 1 million deaths annually – cleaning up the air could inadvertently accelerate warming, requiring further adaptation measures.
Some experts urge caution regarding the pollution hypothesis. Raghu Murtugudde, an emeritus professor at the University of Maryland now residing in Mumbai, notes that Indian aerosol pollution contains soot particles that absorb sunlight, leading to warming rather than cooling. “Aerosols,” he said, “do not seem to explain the seasonal trend,” noting that peak pollution occurs during winter months, which have also seen the greatest warming.
Wind Patterns
Murtugudde suggests that shifting wind patterns could offer another explanation. In a 2023 paper, he and his colleagues found that accelerated warming in the arid Middle East pushed the Arabian Sea’s prevailing winds northward. This shift, they argue, explains the increased extreme rainfall and flooding observed in Pakistan and northwestern India.
Murtugudde is currently investigating whether seasonal wind changes might also contribute to India’s slower average warming.
The Irrigation Factor
A third possible factor is the extensive expansion of irrigation in northern India over the past century. Water evaporating from the soil or transpired by plants absorbs heat from the air, creating a cooling effect. A 2016 study indicated that increased evapotranspiration in the U.S. Midwest, driven by irrigation and intensive agriculture, has moderated the hottest summer days. Similarly, a 2020 study concluded that 20th-century irrigation expansion has lessened global warming, particularly in south Asia.
However, the irrigation hypothesis also faces scrutiny. Some Indian researchers contend that studies relying on satellite measurements and global datasets have overestimated the volume of water pumped for irrigation in northern India,especially during the summer months when irrigation is least prevalent.
Govindasamy Bala, a professor at the Indian Institute of Science’s Center for Atmospheric and Oceanic Sciences, remains unconvinced by any single explanation. He suggests that India’s slower warming primarily reflects its location within the humid tropical band and the inherent variability of the climate system.
India’s climate Puzzle: why Is Warming Slower Than Global Average?
Here’s a breakdown of why India’s warming patterns differ from the global trend, directly addressing the main question and other related points, all based on the provided article.
Q: Why is India’s average annual temperature increase slower than the global average?
A: Despite experiencing record-breaking temperatures, India’s average annual temperature increase since 1901 is less than 0.7 degrees Celsius, about half the global average. Scientists are still investigating the reasons for this unique warming pattern.
Q: What are the main factors contributing to India’s slower warming, according to experts?
A: Experts highlight several potential factors:
Air Pollution: The Indo-Gangetic Plain, a region with severe air pollution, may be playing a role. Pollutants, including aerosols, can reflect sunlight, perhaps cooling the region.
Wind Patterns: Shifting wind patterns, potentially linked to warming in the Middle East, could be influencing India’s climate.
Irrigation: Extensive irrigation in northern India might be creating a cooling effect through evaporation.
Location within the humid tropical band and the inherent variability of the climate system.
Q: How does air pollution influence India’s warming?
A: Air pollution is a leading hypothesis.
Cooling Effect: Aerosols in the air can reflect sunlight.A thick haze of atmospheric pollution can potentially cool the region.
Dilemma: Cleaning up the air, though desperately needed, could inadvertently accelerate warming.
Complexities: Some experts argue that Indian aerosols contain soot particles that absorb sunlight, leading to warming. Also, peak pollution occurs during winter months, which have also seen the greatest warming; challenging the simple cooling hypothesis.
Q: How might wind patterns explain India’s warming trend?
A: Shifting wind patterns could offer another description, according to research.
Shifted Winds: Accelerated warming in the arid Middle East has pushed the Arabian Sea’s prevailing winds northward.
Impact: This shift is believed to explain increased extreme rainfall and flooding in Pakistan and northwestern India.
Q: How does irrigation affect India’s temperature?
A: Irrigation is another possible factor.
Cooling Effect: Water evaporating from the soil absorbs heat, creating a cooling effect. A 2016 study indicated that increased evapotranspiration in the U.S. Midwest has moderated the hottest summer days. A 2020 study concluded that 20th-century irrigation expansion has lessened global warming, particularly in south Asia.
* Scrutiny: Some researchers question the accuracy of irrigation data, suggesting that the volume of water pumped for irrigation has been overestimated, especially during the summer months.
Q: What is the overall conclusion regarding the reasons for India’s slower warming?
A: Govindasamy Bala suggests that India’s slower warming primarily reflects its location within the humid tropical band and the inherent variability of the climate system. He remains unconvinced by any single explanation.
Summary of Factors
| Factor | Description | Potential Effect | Supporting Evidence (from article) |
| —————– | —————————————————————————————————————— | —————————– | ————————————————————————————————————————————————————————— |
| Air Pollution | Dense pollution in the Indo-Gangetic Plain | Cooling (potentially), warming (due to soot) | Aerosols reflect sunlight; though, some aerosols absorb sunlight; peak pollution during winter, which have also seen the greatest warming; pollution contributes to over 1 million deaths annually |
| Wind patterns | Shifting winds from the Arabian Sea due to warming in the Middle East. | Influence Rainfall and Flooding| Accelerated warming in the arid Middle East has pushed the Arabian Sea’s prevailing winds northward. |
| Irrigation | Extensive irrigation in northern India | Cooling | Water evaporation absorbs heat; Studies show increased evapotranspiration has moderated the hottest summer days; 20th-century irrigation expansion has lessened global warming. |
| Tropical Location | India’s location in the humid tropical band and the inherent variability of the climate system. | Slower Warming | Considered as a factor for slower warming. |