Hindukush - Himalayan (HKH) assessment report published by Kathmandu based international centre for integrated mountain development (ICIMOD) :--
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The HKH is young folded greatest mountain system in the world covering 4.2 million sqkm across 8 countries : Afghanistan, Bangladesh, Bhutan, China, India, Myanmar , Nepal and Pakistan. The HKH is also refers to Third pole because of third largest icecover or Glacier outside north and south pole.
This region is vital due to following factors :
1) ecological significance , diverse flora and Fauna, vast reserves of natural resources such as 4 global biodiversity hotspots.
2) Third Pole significance, cryospherically, largest reserves of ice outside the Polar regions. Mountainous Glacier.
3) Water resources role to Asian countries since HKH region is a source of 10 major Asian Rivers such as Gangs, Brahmaputra, Mekong, salween, Irrawaddy, Yangtze, Amur Darya, Tarim, Yellow, Indus.
4) sustainability of people : 240 million people depends directly on the HKH for lives and livelihoods. 1.9 billion people depends on on the HKH for water, food and energy. > 35% of the world population benefits indirectly from HKH resources and ecosystem services. 3 billion people benefits from the food produced in it's river basins.
5) support diverse cultures, languages, religions and traditional knowledge systems of south east Asia, east Asia, South Asia, central Asia.
6) High biodiversity, 330 important Bird and biodiversity areas.
Key issues in HKH are :--
--- vulnerable to erosion and landslides
--- region undergoing rapid change, driven by forces such as climate change, disasters, economic growth, globalisation, infrastructure development, land use change, migration and urbanisation.
--- even if global warming is limited to 1.5°C, warming will be likely be at least 0.3°C higher in the HKH, and at least 0.7°C higher in the North west Himalayas and karakoram. By the end of century (2100), the Hindu Kush Himalaya will warm by around 1.8°C.
--- There has been a rising trend of extreme warm events in the HKH over the past 5-6 decades, a falling trend of extreme cold events.
--- ghg's concentration increase, aerosols, increases and land use changes leads to extreme temperature , days and nights are getting warmer, extremes in precipitation increasing, the HKH will warm more than the global mean. Even Tibetan plateau, central Himalayan range and karakoram will warm more than the HKH average, increasing western disturbances.
--- melting of HKH Glacier leads to thining, retreating, breaking , decreases it's areas, will be affecting water supplies to Asian Rivers and lifelines of more than 35 %of world population get affected, water wars in Asian countries will be accelerating, food insecurity, starvation, hunger and poverty all will be aggravated.
--- biodiversity loss in the HKH region adversely affect the ecosystem and loss of ecosystem services to 1/4th of humanity. Since 1/4th of endemic species in the Indian Himalaya could be wiped out by 2100. The 70-80% of habitat lost in biodiversity in HKJ (relative to 1500A.D.) The 39% of HKH is under protected areas covering 1.6million sqkms. Biodiversity in HKH needs to be sustained to ensure the continued flow of services.
--- The HKH remains energy poor despite it's huge hydropower potential of around 500GW because of low priority and failure to address challenges of remoteness and fragility, inadequate data is a barrier to context specific interventions.
--- the cryosphere of HKH affects the water supply due to decrease in snow covered areas and snow volumes, glaciers have thinned, retreated and ice-mass lost. Permafrost will continue to thaw and the depth of the active layer will increase. There is increased risk of dangerous glacial lake outburst floods (GLOF) since 1990's.
--- Hydrological trends related to cryospheric change are difficult to identify due to influence of discharge, scarcity in long term, high interannual variability.
--- water security or HKH is also described as water tower of Asia because it meltwaters and glaciers supply waters to Rivers, streamflow, groundwater. It provides water and ecosystem services for 2 billion people. Important for ensuring water, food, energy, and environmental security of the continent.
--- Increase in streamflow expected due to climate change till 2050 and decrease in pre-monsoon flow thereafter. Hydropower can disrupt natural flow regimes, inturn harming local irrigation, fisheries and ecosystems. India, Bangladesh, Pakistan and China together account for more than 50% of the worlds groundwater withdrawals.
--- food and nutritional insecurity remains a serious challenge in the HKH. More than 30% of the population suffer from food insecurity and around 50% face malnutrition. It is due to high poverty, natural resources depletion ,climate change, low market development, uncertain food support, inadequate policy and institutional support. The cultivation of traditional crops is declining, with a few crops dominance.
--- Air pollution in HKH is on the rise and air quality has worsened in the past two decades. Indo-Gangetic plains has persistent winter fog and haze. It is due to increase concentration of GHG's , accelerated melting in cryosphere through the deposition of black carbon and dust, and changing monsoon circulation and rainfall distribution over Asia. Aerosols is more absorbed in HKH due to higher concentration of SPM . It leads to melting of snow and glaciers, poor visibility as 90% during winters, affecting shifts in rainfall dynamics.
--- Natural hazards in the HKH are increasing in magnitude and frequency due to climate change such as GLOF events due to the instability of moraine material.
--- mountain regions of the HKH have a higher incidence of economic, multidimensional and income poverty levels than the plains. Around 31%of HKH population is below poverty line, majority of people are poor and politically and socially marginalised.
Sargasso sea is located in the north Atlantic ocean north of Bermuda. It's is the only sea bounded not by land but by oceanic current . The North Atlantic gyre holds the water. It obtained the name from Portuguese word sagassum which means a seaweed. Sargassum is a brown algae which is free floating like a plankton River.
It is confined between 20N -35N degree and 30W-70W degree. It is bounded by north equatorial current in the south, Antilles current in south west, gulf stream in west, north atlantic in the north, Canary current in the east direction. Sargasso sea is characterised by depth 1500m-7000m, still water, saline, evaporation rates >> precipitation rates, horse latitude belt, sargassum seaweed covers 2million square km area in the sea.
Marine biologist declared sargossa sea as biological desert because of lack of nutrients, devoid of plankton in large part of it, absence of large fish. High salinity of Sargasso sea due to lack of oceanic water mixing, high temperature (26) and higher evaporation rates. But known for small marine lifeforms such as turtles,shrimp,crab, small size fishes, eels lay eggs,etc these animals has unique adaptation to high sea weed(Sargassum). Which is not available anywhere on earth.
