1. Ozone layer recovering thanks to Montreal
  2. IPCC 5th Assessment report
  3. Sahara Dust Storm in London

Ozone layer recovering thanks to Montreal

  • Ozone gas in stratosphere prevents 99.5% entry of UV radiation (255nm) on earth.
  • Chlorofluorocarbons / freons: non-reactive, non-flammable, non-toxic. Used in Refrigerators, spray cans, insulation foam and propellant.
  • Once they’re released in atmosphere, they reach stratosphere=> react with UV=> release Chlorine free radicals => Ozone broken.
  • 1980s: Scientists realized Chlorofluorocarbons (CFCs) reach had damaged Ozone layer above Antarctica. Result?
    • Skin cancer, Cataract, Sunburns
    • Phytoplanktons die=> fish population declines.
    • Soil Moisutre content declines, plant proteins are mutated=> plant growth affected.
    • Fibers and Wall paints fade faster.
  • Late 80s: Montreal Protocol signed, to cut down use of
    • chlorofluorocarbons (CFCs) / freons
    • Halons in fire-extinguishers
  • 2014: CFC has declined by 90%, Ozone layer showing signs of recovery- as per United Nations Environment Program (UNEP) and the World Meteorological Organization (WMO).
  • This will also prevented 2 million skin cancer cases per year.
  • 2050: Ozone Layer will recover near mid-latitudes
  • 2075: Ozone layer will recover near Antarctic.


  1. CFCs are replaced with HFCs (Hydroflurocarbons). Although HFCs don’t deplete Ozone layer but they’re greenhouse gases, hence contribute to global warming.
  2. Researchers found Carbon tetrachloride increased in atmosphere. This is a banned ozone-depleting carcinogenic solvent.
  3. Meaning, some companies in the third world countries are still using it illegally, as a cheaper alternative to HFCs.

IPCC 5th Assessment report

Assessment Report (AR) Year
1st 1990
2nd 1995
3rd 2001
4th 2007
5th Yet To Publish Entirely. (Only 2/3 Parts Published)

IPCC 5th Assessment Report (AR5)

Three groups working to prepare this report

group No. working on Published?
1 On physical science and climate change September, 2013
2 Adaption measures [“Impact, Adaption and vulnerability”] March 2014 (hence in news during April 2014)
3 Mitigation measures yet to be published

So now we come to the report that is making news=> Report on “Adaptation measures” under 5th assessment report. Since this is only a small part of the big report yet to come => so, don’t waste time doing lot of Ph.D majoori (labour) in this report.

Overall it says following:

  1. Soil moisture will decline globally => dry regions will become even more drier => global drought =>food shortage.
  2. Temperature has risen 0.2 cel since Industrial revolution.
  3. Climate change is inevitable challenge, but if we understand the challenge correctly then we can better tackle it.
  4. But, Science can help in adaptation and risk reduction. for example:
Sea Level Rise Build coastal barriers and plant mangroves
Agriculture climate resilient seeds and agri-technology
Water Water-conservation, desalination.
Natural Disaster Invest in technology for early detection of cyclones, flood and droughts=> training of personnel, take precautionary measures.

Impact on India?

  1. The poor and developing countries of tropical regions are the most vulnerable of the climate change.
  2. Small island countries of Indian Ocean, like, Maldives, Mauritius and Shri Lanka, will migrate to India as climate refugee. (India has made such agreements with these countries)
  3. Indian coastal cities will face danger of submergence.
  4. Erratic Rainfall, melting of Himalayan glaciers, frequent flooding, draughts, storms and cyclones.
  5. Food insecurity for large population.
  6. New diseases and weather patterns.

Sahara Dust Storm in London

Map Sahara Dust storm
Sahara Desert dust brings smog to UK

  • During summer, the Sahara desert undergoes low pressure depression => dust lifted upwards and flies towards Europe and America
  • locally this is called “Simoom” or poison wind, because it causes heat strokes.
  • In April 2014: a large mass of this dust storm fell over London, hence in news.
good bad
Provides phosphate nutrients to Amazon soil. Continuous and large scale dust storm decreases total soil fertility=forcing villagers to migrate to cities. This happened in USA during 40s, more than 2.5 million people migrated to California.
Provides nutrients to plankton in Mediterranean sea.
  • Poor visibility, smog like situation.
reduces the surface temperature sea and lowers the possibilities of hurricane
  • Dirt accumulation on vehicles, windows, houses =millions cost every year.
Harmattan wind carries this dust in Niger- brining soil nutrients K, Mg and Ca.
  • Allergic reaction in people suffering from asthama= loss of productive man-hours
dust particles directly reflect sunlight backinto space, thus reducing amount of heat coming to Earth’s surface- this has both positive and negative impacts on long term climate.
  • Carries pathogens that destroy coral reefs.
  • Brings iron minerals into sea water = causes algal blooms.