The Gist of Science Reporter: January 2017

The Gist of Science Reporter: January 2017

Action on Climate Change

In recent days, two developments have signalled India's resolve to work with the world community to contain the global rise in temperature below the 2°C warning mark. On 2 October 2016, India ratified the Paris Agreement and on 15 October 2016 the country joined around 200 other countries to seal a legally binding agreement in Kigali, Rwanda to reduce greenhouse gases.

India became the 62nd country to ratify the Paris Agreement. The agreement opened for signature for one year on 22 April 2016. The agreement was supposed to enter into force one month after 55 countries that account for 55 percent of global emissions ratified the agreement. Since India accounts for 4.1 per cent of the emissions, after its ratification the Agreement required around 3 percentage points to reach the 55 per cent threshold. This threshold was achieved on 5 October 2016 when 79 countries, of the 197 member countries, ratified it. Consequently, the Paris Agreement will now enter into force on 4 November 2016.

Among the primary aims of the Paris Agreement are the resolve to keep the increase in the global average temperature below 2°C. It requires all countries to come up with respective national climate action plans to limit global temperature rise and to put their best efforts through an NDC (nationally determined contribution). The Agreement also calls upon developed economies to help poorer nations by providing climate finance of $100 billion a year by 2020.

The other big thing to happen in the month of October was the signing of an agreement between 107 countries in Kigali, Rwanda to substantially phase out hydro fluorocarbons (HFCs), a potent greenhouse gas by 2045, and move to prevent a potential 0.50 C rise in global temperature by 2050. HFCs are used in refrigerants and car airconditioners. They are major culprits in adding to the increasing load of greenhouse gases that substantially worsen global warming. The Kigali agreement calls on the developed countries led by US and Europe to reduce HFC use by 85% by 2045, while India will reduce the use of HFC by 85% by 2047.
Ironically, HFCs began to be used as substitutes for many ozone depleting substances (ODS), which are being phased out under the Montreal Protocol of 1987. ODS are the chief culprits in damaging the stratospheric ozone layer that filters the harmful ultraviolet radiation often linked to increasing instances of skin cancer and cataract. With the agreement signed in Kigali HFCs have also been brought into the ambit of the Montreal Protocol. The agreement comes into force from 1 January 2019.

The two events augur well for the future of the global climate as countries of the world unite to keep a check on the dangerously rising global temperature. The collaboration and cooperation between the members of the world community, one hopes, could prevent the world from sliding into a hot future.

Combating Chromium

Disposal of industrial wastes containing chromium compounds has created a number of contaminated sites, which could pose major environmental threats.

Chromium compounds are reported to have toxic, genotoxic, mutagenic, and carcinogenic effects on humans, animals, plants and in microbes. Occupational exposure of Cr(VI) compounds in Cr-related industries has been associated with respiratory effects and leading to lung, nasal, and sinus cancers. They are also highly toxic to plants, retarding their growth and development. It can cause severe phytotoxicity that may result in reduction of seed germination, pigmentation, nutrient imbalance, and decrease in antioxidant and enzyme concentration.

Cr(VI) has been designated as a "priority pollutant" as it is widely used in industrial processes such as electroplating, leather tanning, textile dyeing, chemical production, metal refining, pigment production, wood preservatives and refractory industries etc.

Cr(VI) is 100 times more toxic than Cr(III), penetrating biological membranes more easily than Cr(III). The reduction of Cr(VI) to Cr(III) can prevent the harm accruing from contaminated environments. Recent research studies have reported that organisms such as Bacillus subtilis, Pseudomonas, Achromobacter, Micrococcus and Escherichia coli possess the capacity to reduce Cr(VI) to Cr(III). This process, also known as bioremediation, is a waste management technique that involves the use of microorganisms to remove or neutralize pollutants from a contaminated site.

Biorernediation "of chromium may be the best-suited -technology to clean Lip chromium' taminated sites. Some new techniques particularly genetic engineering, transcriptomics, and proteomics are being used as tools to study the microbial assisted attenuation of contaminants to accelerate bioremediation.

Chromium toxicity can stunt plant growth.

Historic Launch by ISRO

The Indian Space Research Organisation (ISRO) has yet again notched a first. Its PSLV C-35 rocket launched eight satellites, into two different orbits on 26 September 2016.

The Polar Satellite Launch Vehicle placed the 371 kg SCATSAT-1, a satellite for weather-related studies, in the polar sun synchronous orbit at an altitude of 730 km. And then, two hours later, the PSLV placed two more satellites and five commercial payloads into another orbit. While the 10-kg PRATHAM belonged to lIT Bombay, the 5.25 kg PISAT was designed by the PES University in Bengaluru.

ISRO chairman Mr A.S. Kiran Kumar called the launch a "landmark day in the history of ISRO" as it was the longest PSLV launch by ISRO and one that placed satellites in two different orbits. The rocket Zas re-ignited twice during its flight to place the set of satellites in different orbits.

SCATSAT-1 is meant to provide weather forecasting services. lIT Bombay's PRATHAM intends to estimate the total electron count with a resolution of 1km x 1km location grid, while PISAT (5.25 kg) from PES University in Bengaluru intends to explore remote sensing applications.

The other commercial payloads launched by PSLV C-35 include three payloads from Algeria (ALSAT-1B, 2B and 1N) and one each for Canada (NLS-19) and the United States (Pathfinder-1)
Algeria's ALSAT-1B is an earth observation satellite (103 kg), ALSAT-2B a remote sensing satellite (117 kg) and ALSAT-1N (7 kg) a technology demonstrator. Canada's NLS-19 is a technology demonstration micro satellite (8 kg) and Pathfinder-1 is a commercial high resolution imaging micro satellite (44 kg).

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