Report lacks region specific-information; methodology used is questionable, say experts in India
A recent World Bank report recommending reduction of common pollutants like soot or black carbon and methane in the Himalayan region to slow global warming has drawn severe criticism from Indian scientists.
Reducing emissions of black carbon and methane can not only save lives by reducing air pollutants in atmosphere but also bring down ice melt which is responsible for catastrophes like Uttarakhand disaster of June 2013; and it needs solutions like using environment-friendly cooking stoves, the report had said. Though the benefits will be seen worldwide, countries around Himalayan range will capitalise on it the most, the report added.
Scientists in India say that the report does not give region-specific data and, therefore, will not have much impact on policy makers. They have indicated that combining both black carbon and methane cannot be justified as the lifespan of both is very different.
| How measures can benefit the Himalayas more than other regions:
- Annual temperature increase avoided: about 0.3°C
- Annual premature mortality avoided: 1,238,000
- Annual increase in staple crops: 15.4 million tonnes
- Greatest black carbon reduction benefits: cooking stoves (about 75 per cent of impacts), road diesel and off-road mobile diesel, open burning
- Greatest methane reduction benefits come from: oil and gas, coal mines, landfills (85 per cent of impact)
Titled, On Thin Ice: How Cutting Pollution can Slow Warming and Save Lives
, the report was jointly released by the WB and International Cryosphere Climate Initiative. It talks about impacts of pollution on climate change on cryosphere, the regions on Earth with water in its solid form. It talks about 14 specific measures that the world could take by 2030 to reduce short-lived climate pollutants (SLCP) and slow the melting of ice and snow that must stay frozen to keep oceans and global temperatures from rising even faster. The report says that actions to stabilise cryosphere will also save lives by mitigating SLCP. It makes predictions about the mitigation of climate change by reducing black carbon and methane emissions.
For example, by quickly scaling up just four clean cooking solutions, we could save one million human lives every year, saving primarily women and children from exposure to indoor and outdoor cooking smoke. The same effort would reduce warming impact of black carbon from cooking stoves on polar and mountain regions, especially in the Himalayas, the report said.
The Himalayan mountain ranges are the biggest source of freshwater after polar region. They account for nearly 10 per cent of total freshwater available across the globe and are home to about 1.5 billion people. According to the report, the surface temperature in the region is 1.5 °C higher than what it was before the industrial revolution, thereby, causing some glaciers to melt. Many mountain tops which used to remain snow-capped throughout the year, now don brown peaks. Reviewing black carbon and methane emission measures could slow warming in the Arctic by more than 1°C by 2050, resulting in up to 40 per cent reduced loss of summer sea ice and 25 per cent reduced loss of springtime snow cover. The report also suggests that by putting these measures in place, the Himalayan cryosphere might witness temperature rise that would be nearly 1°C less than what it could otherwise, though these projections are uncertain.
The report talks about five prominent cryospheres—The Himalaya, Arctic, Andes in South America, East African Highlands, and Antarctica. It says that globally, the land exposed due to melting of permafrost, soil at or below the freezing point of water 0 °C (32 °F) for two or more years, is expected to release as much as 30 per cent more carbon into the atmosphere by 2100.
The researchers who prepared the report also calculated that "just a 50 per cent drop in open field and forest burning, another leading source of black carbon, could result in 190,000 fewer deaths from air pollution. By reducing emissions from diesel transport we could avert yet another 340,000 premature deaths." Same measures will give quick gains in fight against climate change.
The report has come under sharp criticism for a variety of reasons.
"Black carbon and methane cannot be clubbed together. Lifespan of the former is a few weeks, while that of latter is 10 years," said J Srinivasan, chairperson, Divecha Centre for Climate Change at Indian Institute of Science (IISc), Bengaluru. “Both the pollutants fall in the category of short-lived climate pollutants, which are agents that have relatively short lifetime (a few days to a few decades ) as compared to carbon dioxide in the atmosphere and have a warming influence on climate.
The report was discussed earlier in February at a workshop on mitigation of harmful effects of aerosols, such as black carbon, in South Asia. The general consensus at the workshop, conducted by IISc, was that reducing aerosols will lead to many health benefits but the impact on climate is not clear.
Srinivasan added that the report did not mention what causes greater climate change – black carbon or methane. “How do we decide which one is more important?" he asked. According to him, another problem pointed out at the workshop was that there is no information about regional impacts on climate. Hence, the report will not be useful for policy making at regional level.
"India produces a small proportion of world's methane emissions. At the same time, the country produces more black carbon emissions on account of high levels of air pollution. Again, methane reduction will impact temperatures while black carbon reduction will have positive health impacts. India should focus on reduction of black carbon since it can lead to immediate health benefits,” said the official.
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