CLIMATE CHANGE

Act Now

• This is the United Nations global call to individual action on climate change.

• The campaign is a critical part of the UN’s coordinated effort to raise awareness, ambition, and action for climate change and accelerate implementation of the Paris Agreement.

•  It is primarily an online and social media campaign that seeks to educate and encourage individual actions, mainly by adjusting consumption patterns.

•  ActNow harnesses advances in Artificial Intelligence (AI) to spur behaviour change.

United Nations Global Commission on Adaptation (GCA)

• The Global Commission on Adaptation was launched in Hague in 2018 by then UN Secretary General Ban Ki-moon.

•  Its mandate is to encourage the development of measures to manage the effects of climate change through technology, planning and investment.

•  It was launched with the support of 17 convening countries including China, Canada and the UK and low-lying countries vulnerable to climate change including Bangladesh and the Marshall Islands.

• The Netherlands initiated the Global Commission on Adaptation to share its knowledge on how it has managed to adopt innovative water management solutions as sea levels rise.

Study on Regional Climatic Features

Indian Institute of Geomagnetism (IIG) has tracked climate change by following the Paleo monsoonal pattern of the subcontinent by harnessing magnetic mineralogy.

The magnetic minerals are sensitive to the physical and chemical environment that they are embedded in.

These external changes bring about modifications in the innate structure of these magnetic minerals, transitioning them from one magnetic phase to another.

In this process, the magnetic mineralogy also changes. For example, from magnetite to hematite and vice versa.

The mineral magnetic studies have unraveled 4 regional climatic features encompassing the entire Indian subcontinent and one localized climatic event, they are as follows

• Higher monsoon precipitation in the western part of India was shown to be analogous with glacial melt in the Himalayas.

• The weakening of monsoon was inferred in the Himalayas and the hinterland of Arabian Sea, analogically cold and dry conditions were prevalent at Dhakuri (Uttarakhand), which led to the formation of loess deposits.

• The monsoon intensification is deciphered in the western and eastern part of India with major implications in the hinterlands of the Arabian Sea and Bay of Bengal.

•  Holocene aridity and weakened monsoon was inferred to be prevalent across the subcontinent (Holocene is the current geological epoch).

• The localized feature of Younger Dryas cooling seems to be confined to just the upper reaches of the Himalaya, Younger Dryas is a period of rapid cooling in the late Pleistocene.

• The type of climate we experience now might be prevailing over the last 10,000 years with minor and occasionally wide fluctuations.

• The planet earth has witnessed many variations in climate since the beginning

• The geomorphological features, especially in high altitudes and high latitudes, exhibit traces of advances and retreats of glaciers.

• The sediment deposits in glacial lakes also reveal the occurrence of warm and cold periods

Evolution of climate change

• India also witnessed alternate wet and dry periods. Archaeological findings show that the Rajasthan desert experienced wet and cool climate around 8,000 B.C.

• The period 3,000- 1,700 B.C. had higher rainfall. From about 2,000-1,700 B.C., this region was the centre of the Harappan civilisation. Dry conditions accentuated since then.

• In the geological past, the earth was warm some 500-300 million years ago, through the Cambrian, Ordovician and Silurian periods.

• During the Pleistocene epoch, glacial and inter-glacial periods occurred, the last major peak glacial period was about 18,000 years ago.

• The present inter-glacial period started 10,000 years ago

Recent examples

• The 1990s recorded the warmest temperature of the century and some of the worst floods around the world.

• The worst devastating drought in the Sahel region, south of the Sahara desert, from 1967-1977 is one such variability.

• During the 1930s, severe drought occurred in southwestern Great Plains of the United States, described as the dust bowl.

Causes of Climate Change

• The causes for climate change are many. They can be grouped into

1. Astronomical – [Sunspot activities and Volcanism ]
2. Terrestrial causes – [Green House gases, Pollution and aerosols, Ground level ozone]

• The astronomical causes are the changes in solar output associated with sunspot activities.

Sunspots are dark and cooler patches on the sun which increase and decrease in a cyclical manner.

• According to some meteorologists, when the number of sunspots increase, cooler and wetter weather and greater storminess occur.

• A decrease in sunspot numbers is associated with warm and drier conditions

Volcanism is considered as another cause for climate change. Volcanic eruption throws up lots of aerosols into the atmosphere.

• These aerosols remain in the atmosphere for a considerable period of time reducing the sun’s radiation reaching the Earth’s surface

• The most important anthropogenic effect on the climate is the increasing trend in the concentration of greenhouse gases in the atmosphere which is likely to cause global warming.

Global Warming

• Due to the presence of greenhouse gases, the atmosphere is behaving like a greenhouse.

• The atmosphere also transmits the incoming solar radiation but absorbs the vast majority of long wave radiation emitted upwards by the earth’s surface.

• The gases that absorb long wave radiation are called greenhouse gases.

• The processes that warm the atmosphere are often collectively referred to as the greenhouse effect.

Origin of the term Green house

• The term greenhouse is derived from the analogy to a greenhouse used in cold areas for preserving heat.

• A greenhouse is made up of glass.  The glass which is transparent to incoming short wave solar radiation is opaque to outgoing long wave radiation.

• The glass, therefore, allows in more radiation and prevents the long

wave radiation going outside the glass house, causing the temperature inside

• the glasshouse structure warmer than outside.

• During summers interiors or cars where windows are closed, becomes unusually heated due to Greenhouse effect.

Greenhouse Gases(GHGs)

The primary GHGs of concern today are carbon dioxide (CO2), Chlorofluorocarbons (CFCs), methane (CH4), nitrous oxide (N2O) and ozone (O3).

Some other gases such as nitric oxide (NO) and carbon monoxide (CO) easily react with GHGs and affect their concentration in the atmosphere

Measuring the effectiveness of GHGs

• The effectiveness of any given GHG molecule will depend on the magnitude of the increase in its concentration, its life time in the atmosphere and the wavelength of radiation that it absorbs.

• The chlorofluorocarbons (CFCs) are highly effective.

• Ozone absorbs ultra violet radiation in the stratosphere is very effective in absorbing terrestrial radiation when it is present in the lower troposphere

• Longer the GHG, more is the Danger to the environment

Concentration of GHGs

• The largest concentration of GHGs in the atmosphere is carbon dioxide. The emission of CO2 comes mainly from fossil fuel combustion (oil, gas and coal).

• Forests and oceans are the sinks for the carbon dioxide. Forests use CO₂ in their growth.

• So, deforestation due to changes in land use, also increases the concentration of Co₂

• The CO₂ It is rising at about 0.5 per cent annually. Doubling of concentration of CO ₂ over pre-industrial level is used as an index for estimating the changes in climate in climatic models

• Chlorofluorocarbons (CFCs) are products of human activity.

• Ozone occurs in the stratosphere where ultra-violet rays convert oxygen into ozone.
• Ultra violet rays do not reach the earth’s surface. The CFCs which drift into the stratosphere destroy the ozone.

• Large depletion of ozone occurs over Antarctica. The depletion of ozone concentration in the stratosphere is called the ozone hole.

The increasing trend in the concentration of GHGs in the atmosphere may, in the long run, warm up the earth. Once the global warming sets in, it will be difficult to reverse it. Rise in the sea level due to melting of glaciers and ice-caps and thermal expansion of the sea may inundate large parts of the coastal area and islands, leading to social problems.

RECENT DEVELOPMENTS TO COMBAT CLIMATE CHANGE

Act Now

• This is the United Nations global call to individual action on climate change.

• The campaign is a critical part of the UN’s coordinated effort to raise awareness, ambition, and action for climate change and accelerate implementation of the Paris Agreement.

•  It is primarily an online and social media campaign that seeks to educate and encourage individual actions, mainly by adjusting consumption patterns.

•  Act Now harnesses advances in Artificial Intelligence (AI) to spur behaviour change.

United Nations Global Commission on Adaptation (GCA)

• The Global Commission on Adaptation was launched in Hague in 2018 by then UN Secretary General Ban Ki-moon.

•  Its mandate is to encourage the development of measures to manage the effects of climate change through technology, planning and investment.

•  It was launched with the support of 17 convening countries including China, Canada and the UK and low-lying countries vulnerable to climate change including Bangladesh and the Marshall Islands.

• The Netherlands initiated the Global Commission on Adaptation to share its knowledge on how it has managed to adopt innovative water management solutions as sea levels rise.

Study on Regional Climatic Features

• Indian Institute of Geomagnetism (IIG) has tracked climate change by following the Paleo monsoonal pattern of the subcontinent by harnessing magnetic mineralogy.

• The magnetic minerals are sensitive to the physical and chemical environment that they are embedded in.

• These external changes bring about modifications in the innate structure of these magnetic minerals, transitioning them from one magnetic phase to another.

• In this process, the magnetic mineralogy also changes. For example, from magnetite to hematite and vice versa.

• The mineral magnetic studies have unraveled 4 regional climatic features encompassing the entire Indian subcontinent and one localized climatic event, they are as follows

Emissions Gap Report’

• United Nations Environment Programme (UNEP) releases ‘Emissions Gap Report’,

• India is the fourth-largest emitter of Green House Gases (GHGs) according to the report.

• According to the report, unless global greenhouse gas emissions fall by 7.6 per cent each year, the world will fail to meet the 1.5°C temperature goal of the Paris Agreement.

• The top four emitters (China, USA, EU and India) contribute to over 55 per cent of the total emissions over the last decade, excluding emissions from land-use change such as deforestation, the report states.

• If land-use change emissions were included, the rankings would change, with Brazil likely to be the largest emitter.

• Sectors that are the largest emitters

Energy >Industry> Forestry> Transport>  Agriculture>  Building.

• The report, however, adds that India is among a small group of countries that are on track to achieve their self-declared climate targets under the Paris Agreement.