1.Shifting paradigms in climate change fight (Down to Earth)

2.Importance of Antarctica for the world (The conversation)

1.Shifting paradigms in climate change fight (Down to Earth)

Synoptic line: It throws light on how very soon the emissions from domestic sewage may out run the pollution from fertilisers. (GS paper III)

Overview

  • The fight against environmental pollution could soon witness a paradigm shift, with a new study showing that domestic sewage is increasingly becoming a major source of Nitrogen pollution. The finding assumes importance as till now vehicular emission and fertiliser sector were considered as the main sources of Nitrogen pollution in that order. This assumption has to now change.
  • The startling finding could be because all this while not much data was available on Nitrogen pollution generated by domestic sewage.

The study

  • The study team was set was in 2006 by Society for Conservation of Nature, a voluntary body of scientists. The task force was named Indian Nitrogen Group (ING). It consisted of experts from diverse backgrounds and was mandated to review the problem of pollution posed by reactive Nitrogen in a comprehensive manner.
  • Officials suggested that the Government of India’s Swachh Bharat Abhiyan to promote cleanliness in the country could be leveraged to encourage safer disposal of sewage. Nitrogen emission from domestic sewage is growing at nearly four times as compared to fertilisers. Very soon the emissions from sewage may out run the pollution from fertilisers. This may not be a problem in the West.
  • They have better disposal and recovery system in place. We should extract active nitrogen from the sewage and use them again as fertilizer. This would also reduce the fertiliser burden and save public money.

Main highlights

  • The study has also highlighted that many water bodies in the country are facing extinction in the wake of increasing Nitrogen pollution. The reactive nitrogen in Indian environment is mainly in the form of nitrous oxide coming from vehicular exhaust and Ammonia coming from fertilizers, livestock and sewage.
  • The active nitrogen going up into the atmosphere falls back along with the rain in noxious forms.  The active nitrogen rich rain pollutes the water bodies increasing the nutrient in them leading to growth of algae.
  • Water bodies rich in nitrogen and phosphorus appear lush green, and once the dissolved oxygen is diminished by extraordinary growth of plants the water body turns brown and eventually red destroying all the aquatic life including fish. Finally the pond dies completely.
  • Active Nitrogen pollution has not just affected the surface water bodies, but has also seeped into the ground water, polluting them.  At several places in the country the levels of active nitrogen in drinking water is nearly twice the limits prescribed by the World Health Organisation (WHO).
  • Even forests in remote corners are being affected in a large way. “We see sudden blooms of lush growth even in remote forest areas untouched by human hand. They are being fertilized by the active nitrogen rich rain.
  • The new study should help change the general perception that over use of fertilisers was the main source of active nitrogen pollution.  “For the last few decades the active nitrogen load in the environment is being measured and there had been a tendency to blame the alarming levels of increase in the environment entirely on the fertiliser sector. The real truth is different. It is not the only one to be blamed.

Need to regulate nitrogen

  • There is an urgent need to regulate the use of fertilisers. Studies indicate that only about 30% of the nitrogen in the fertilisers that are applied is assimilated by the plant. The balance is going into the environment, polluting air, water and land.
  • Due to poor returns on agriculture and other factors, farmers are not able to practice precision agriculture, applying small doses of fertilizers many times. Instead, they resort to applying fertilisers fewer times in large doses. Plants cannot take the excess fertilisers and the unused portion goes on to pollute land, air and water. In India, cereal crop production has very low Nitrogen Use efficiency.
  • Concerns over global warming resulting from accumulation of greenhouse gases take into account active nitrogen pollution too. Human activity releases twice the amount of reactive nitrogen as nature. In the case of CO2, on the other hand, Nature contributes the bulk. Only five to ten percent of CO2put into atmosphere every year is anthropogenic. N2O is 300 times potent greenhouse gas than CO.

Way ahead

  • We need a re-look at our fertiliser policy, especially urea pricing.Decisions like mandating neem coated urea as the only source to be sold in retail market and reducing the pack-size of urea bag would contribute substantially to reduction of the active nitrogen pollution.
  • Active nitrogen pollution also makes the soil lose its carbon content. We must balance various nutrients we apply to the soil. Applying active nitrogen alone leads to reduction of carbon content, but if nitrogen is applied along with potassium and phosphorus carbon reduction is substantially arrested.

Question: We should extract active nitrogen from the sewage and use them again as fertiliser in order to reduce Nitrogen content in water. Comment.

2.Importance of Antarctica for the world (The conversation) 

Synoptic line: It throws light on the importance of Antarctica as it holds a staggering amount of water; the three ice sheets that cover the continent contain around 70 per cent of our planet’s fresh water. (GS paper III)

Overview

  • Antarctica has been popularly described as remote and extreme. Over the past two centuries, these factors have combined to create, in the human psyche, an almost mythical land an idea reinforced by tales of heroism and adventure.
  • Recent research, however, is casting new light on the importance of the southernmost continent, overturning centuries of misunderstanding and highlighting the role of Antarctica in how our planet works and the role it may play in a future, warmer world.

Importance of Antarctica

  • Antarctica holds a staggering amount of water. The three ice sheets that cover the continent contain around 70% of our planet’s fresh water, all of which we now know to be vulnerable to warming air and oceans. If all the ice sheets were to melt, Antarctica would raise global sea levels by at least 56m.

The importance to conserve

  • Where, when, and how quickly they might melt is a major focus of research. No one is suggesting all the ice sheets will melt over the next century but, given their size, even small losses could have global repercussions. Possible scenarios are deeply concerning: in addition to rising sea levels, meltwater would slow down the world’s ocean circulation, while shifting wind belts may affect the climate in the southern hemisphere.
  • In 2014, NASA reported that several major Antarctic ice streams, which hold enough water to trigger the equivalent of a one-and-a-half metre sea level rise, are now irreversibly in retreat. With more than 150m people exposed to the threat of sea level rise and sea levels now rising at a faster rate globally than any time in the past 3,000 years, these are sobering statistics for island nations and coastal cities worldwide.
  • Recent storm surges following hurricanes have demonstrated that rising sea levels are a future threat for densely populated regions such as Florida and New York. Meanwhile the threat for low-lying islands in areas such as the Pacific is immediate and acute.
  • Multiple factors mean that the vulnerability to global sea level rise is geographically variable and unequal, while there are also regional differences in the extremity of sea level rise itself. At present, the consensus of the IPPC 2013 report suggests a rise of between 40 and 80cm over the next century, with Antarctica only contributing around 5cm of this. Recent projections, however, suggest that Antarctic contributions may be up to ten times higher.
  • Studies also suggest that in a world 1.5-2°C warmer than today we will be locked into millennia of irreversible sea level rise, due to the slow response time of the Antarctic ice sheets to atmospheric and ocean warming.
  • We may already be living in such a world. Recent evidence shows global temperatures are close to 1.5°C warmer than pre-industrial times and, after the COP23 meeting in Bonn in November, it is apparent that keeping temperature rise within 2°C is unlikely.

Way ahead

  • We now need to reconsider future sea level projections given the potential global impact from Antarctica. Given that 93% of the heat from anthropogenic global warming has gone into the ocean, and these warming ocean waters are now meeting the floating margins of the Antarctic ice sheet, the potential for rapid ice sheet melt in a 2°C world is high.
  • In polar regions, surface temperatures are projected to rise twice as fast as the global average, due to a phenomenon known as polar amplification. However, there is still hope to avoid this sword of Damocles, as studies suggest that a major reduction in greenhouse gases over the next decade would mean that irreversible sea level rise could be avoided.
  • It is therefore crucial to reduce CO₂ levels now for the benefit of future generations, or adapt to a world in which more of our shorelines are significantly redrawn.
  • This is both a scientific and societal issue. We have choices: technological innovations are providing new ways to reduce CO₂ emissions, and offer the reality of a low-carbon future. This may help minimise sea level rise from Antarctica and make mitigation a viable possibility.

Question: Given what rising sea levels could mean for human societies across the world, we must maintain our longstanding view of Antarctica as the most remote and isolated continent. Comment.