Current Affairs Oct 6

Clouds Role  in the Climate change puzzle

• In some climate models, clouds strongly amplify warming. 

• In others, they have a neutral effect or even dampen warming slightly. 

Why are clouds so important?

• Clouds can act like a parasol, cooling the Earth by reflecting sunlight away from the planet’s surface and back into space. 

• But they can also act like an insulating blanket, warming the Earth by preventing some of the heat in our atmosphere from escaping into space as infrared radiation. 
• This “blanket” effect is particularly noticeable during the winter, when cloudy nights are typically much warmer than cloud-free ones.
• Which of these two effects dominates—parasol or blanket—depends on the altitude and thickness of the clouds. 

• As a general rule, the higher a cloud is, the more effective it is at preventing heat from escaping into space. 

• The thicker a cloud is, the better it is at reflecting sunlight away from Earth’s surface.

• High, thin clouds let sunlight through while effectively preventing heat from escaping to space as infrared radiation, providing a net warming effect. 

• Low, thick clouds strongly reflect sunlight, while having little impact on infrared radiation escaping to space, creating a net cooling effect.

• As the atmosphere contains far more low, thick clouds than high, thin clouds, the parasol effect dominates and our planet would be much hotter if clouds did not exist.

The clouds are changing

• Global warming is expected to cause changes in the amount of cloud cover, and the height and thickness of these clouds in the future, shifting the balance between the parasol and blanket effects of clouds. 

• The knock-on effect this will have on temperature is known as cloud feedback.

• Clouds are more likely to amplify global warming than they are to dampen it for two reasons.
• First, the cover of low clouds is expected to decrease in the tropics as global temperatures rise, reducing their parasol effect. 
• Second, it is well understood that high clouds will move into higher regions of the atmosphere as it warms, making them more effective blankets. 
• These warming effects may be mitigated slightly by an increase in the thickness of clouds at high latitudes only, particularly over the Southern Ocean around Antarctica, but this will not cancel out the overall warming effect.

Dangerous 1.5℃ warming limit

• The Paris climate agreement seeks to limit global warming to 1.5℃ this century. 

• A new report by the World Meteorological Organisation warns this limit may be exceeded by 2024 — and the risk is growing.

• This first overshoot beyond 1.5℃ would be temporary, likely aided by a major climate anomaly such as an El Niño weather pattern. 

• However, it casts new doubt on whether Earth’s climate can be permanently stabilised at 1.5℃ warming.

• The report also found while greenhouse gas emissions declined slightly in 2020 due to the COVID-19 pandemic, they remained very high — which meant atmospheric carbon dioxide concentrations have continued to rise.

Greenhouse gases rise as CO䔖missions slow

• Concentrations of the three main greenhouse gases — 

• carbon dioxide (CO䔖, methane (CH䔬 and nitrous oxide (N䔖), have all increased over the past decade. 

• Current concentrations in the atmosphere are, respectively, 147 per cent, 259 per cent and 123 per cent of those present before the industrial era began in 1750.

• Growth in CO䔖missions from fossil fuel use slowed to around one per cent per year in the past decade, down from three per cent during the 2000s. 

• Although emissions will fall slightly, atmospheric CO䔖oncentrations will still reach another record high this year. 

• This is because we’re still adding large amounts of CO䔖o the atmosphere.

Warmest five years on record

• The global average surface temperature from 2016 to 2020 will be among the warmest of any equivalent period on record, and about 0.24℃ warmer than the previous five years.

• This five-year period is on the way to creating a new temperature record across much of the world, including Australia, southern Africa, much of Europe, the Middle East and northern Asia, areas of South America and parts of the United States.

• Sea levels rose by 3.2 millimetres per year on average over the past 27 years. 
• The growth is accelerating — sea level rose 4.8 millimetres annually over the past five years, compared to 4.1 millimetres annually for the five years before that
• The past five years have also seen many extreme events. 

• These include record-breaking heatwaves in Europe, Cyclone Idai in Mozambique, major bushfires in Australia and elsewhere, prolonged drought in southern Africa and three North Atlantic hurricanes in 2017.

1 in 4 chance of exceeding 1.5°C warming

• There’s a one-in-four chance the global annual average temperature will exceed 1.5℃ above pre-industrial levels for at least one year over the next five years.

• The chance is relatively small, but still significant and growing. If a major climate anomaly, such as a strong El Niño, occurs in that period, the 1.5℃ threshold is more likely to be crossed. 

• El Niño events generally bring warmer global temperatures.

Pesticides Management Bill, 2020

• The Pesticides Management Bill (PMB), 2020 — introduced in the Rajya Sabha to replace The Insecticides Act, 1968 — will have a far-reaching impact on Indian agriculture and famers’ livelihood if it is passed in the current form.

• The Insecticides Act, 1968 currently governs the registration, manufacturing, export, sale and use of pesticides in India. It will come up for discussion in the upcoming Monsoon Session of Parliament.

• PMB, 2020 would not allow the manufacture and export of pesticides not registered for use in India even if these are approved in other countries.

• PMB, 2020 does not reflect the government’s repeated emphasis on the need for doubling farmer’s income by 2022.

• The demands presented by the Ashok Dalwai Committee, constituted in 2018 to promote domestic and indigenous industries and agricultural exports from India, are missing from PMB, 2020. 

• The committee had recommended reduction in import and dependence on imported formulations. 

• The present PMB, however, will increase the import of formulations and will damage the export of agro-chemicals.

 WWF’s Living Planet Report 2020

• The WWF’s (World Wildlife Fund) Living Planet Report 2020, has found that there has been a reduction of 68 per cent in the global wildlife population between 1970 and 2016. 

• 75 per cent of the the Earth’s ice-free land surface has already been significantly altered, most of the oceans are polluted, and more than 85% of the area of wetlands has been lost during this period.

• The most important direct driver of biodiversity loss in the last several decades has been land-use change, primarily the conversion of pristine habitats into agricultural systems, while much of the oceans have been overfished.

• The highest biodiversity loss due to land use change globally has been found in Europe and Central Asia at 57.9 per cent, 

• then in North America at 52.5 per cent, Latin America and Caribbean at 51.2 per cent, Africa at 45.9 per cent and then Asia at 43 per cent.

• Other factors leading to biodiversity loss include species overexploitation (like overfishing), invasive species and diseases, as well as pollution and climate change.

• The largest wildlife population loss, according to the Living Planet Index, has been in Latin America at an alarming 94 per cent.

• One of the most threatened biodiversity globally has been freshwater biodiversity, which has been declining faster than that in oceans or forests. 

• Almost 90 per cent of global wetlands have been lost since 1700 and global mapping has recently revealed the extent to which humans have altered millions of kilometres of rivers.

• India, a “megadiverse country” with over 45,000 species of plants in only 2.4 per cent of the world’s land area, 

• has already lost six plant species to extinction, according to the IUCN Red List. 
• The report further finds that India has lost nearly one-third of its natural wetlands to urbanisation, agricultural expansion and pollution over the last four decades.
• The World Wide Fund for Nature (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment.

•  It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States.

• WWF aims to “stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature. 

• The Living Planet Report has been published every two years by WWF since 1998; it is based on a Living Planet Index and ecological footprint calculation. 

• In addition, WWF has launched several notable worldwide campaigns, including Earth Hour and Debt-for-Nature Swap, and its current work is organized around these six areas: food, climate, freshwater, wildlife, forests, and oceans.

Climate crisis could displace 1.2bn people by 2050

• More than 1 billion people face being displaced within 30 years as the climate crisis and rapid population growth drive an increase in migration with “huge impacts” for both the developing and developed worlds.

• The Institute for Economics and Peace (IEP), a thinktank that produces annual global terrorism and peace indexes, said 1.2 billion people lived in 31 countries that are not sufficiently resilient to withstand ecological threats.

• Nineteen countries facing the highest number of threats, including water and food shortages and greater exposure to natural disasters, are also among the the world’s 40 least peaceful countries.

• Many of the countries most at risk from ecological threats, including Nigeria, Angola, Burkina Faso and Uganda, are also predicted to experience significant population increases.

• Ecological threats pose serious challenges to global peace. 

• Over the next 30 years, lack of access to food and water will only increase without urgent global cooperation. 

• In the absence of action, civil unrest, riots and conflict will most likely increase.

• It found that 141 countries faced at least one ecological threat by 2050, with sub-Saharan Africa, South Asia, the Middle East and North Africa the regions facing the largest number.

• Some countries, such as India and China, are most threatened by water scarcity, it concluded, while others such as Pakistan, Iran, Kenya, Mozambique and Madagascar face a combination of threats and a growing incapacity to deal with them.

• Pakistan to be the country with the largest number of people at risk of mass migration, followed by Ethiopia and Iran, 

• in such countries “even small ecological threats and natural disasters could result in mass population displacement”.
• 16 countries, Sweden, Norway, Ireland, and Iceland, faced no threat.
• The world had 60% less fresh water available than it did 50 years ago, 

• while demand for food was predicted to rise by 50% by 2050 and

•  natural disasters were only likely to increase in frequency because of the climate crisis, 

• meaning even some stable states would become vulnerable by 2050.

Leaked UN report on biodiversity

• Positive actions to improve the condition of forests, agriculture, food systems, climate, human health, fisheries, oceans and cities have been suggested by experts to ensure human well-being and save the planet in a United Nations (UN) report.

• The Global Biodiversity Outlook 5 report or GBO-5 is to be released on September 15, 2020. 

• The GBO-5 is an overview of the state of nature. 

• It is a final report card on the progress made by countries in achieving the Aichi Biodiversity Targets.

• These 20 global biodiversity targets were included in the Strategic Plan for Biodiversity for the 2011-2020 period adopted by the 10th meeting of the Conference of the Parties of the Convention on Biological Diversity. 

• But none of the 20 Aichi biodiversity targets have been met, the GBO-5 has shown.

The GBO-5 suggested eight types of shift that need to be implemented to achieve the 2050 Vision for Biodiversity. These include:

• Transition within land and forests: The report called the restoration of all forests that had been degraded. It also urged restoring local ecosystems.

• Sustainable agriculture: Farmers would have to reduce the use of chemicals and instead focus more on agroecological farming practices.

• Sustainable food systems: The report urged people to eat healthier, plant-based food and less meat. It also called for focussing on the problem of food wastage within the supply chain and household.

• Climate action: The report called for nature-based solutions to reduce climate change.

• One health: Agricultural and urban ecosystems, as well as wildlife should be managed in an integrated manner, it said.

• Sustainable management of fisheries, oceans and freshwater as well as sustainable development of cities and infrastructure were the other areas in which the shift needed to take place

Aichi Biodiversity Targets

• Strategic Goal A: Address the underlying causes of biodiversity loss by mainstreaming biodiversity across government and society

• Strategic Goal B: Reduce the direct pressures on biodiversity and promote sustainable use

• Strategic Goal C: To improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity

• Strategic Goal D: Enhance the benefits to all from biodiversity and ecosystem services

• Strategic Goal E: Enhance implementation through participatory planning, knowledge management and capacity building

Indian monsoon can be predicted better after volcanic eruptions

• Large volcanic eruptions can help to forecast monsoons over India. 

• This seasonal rainfall is key for the country’s agriculture and thus for feeding 1 billion people. 

• As erratic as they are, volcanic eruptions improve the predictability, an Indian-German research team finds. 

• What seems to be a paradox is, in fact, due to a stronger coupling between the monsoon over large parts of South and South-East Asia and the El Niño phenomenon after an eruption. 

• Combining data from meteorological observations, 

• climate records, computer model simulations and 

• such geological archives as tree-rings, corals and 

• ice-cores from past millennia of Earth history, 
• the researchers found that a synchronization of the monsoon with the strongest mode of natural climate variability, El Niño, makes it easier to anticipate the strength of seasonal rainfall in the Indian subcontinent.
• The tiny particles and gasses that a large volcano blasts into the air enter into the stratosphere and remain there for a few years. 

• While the volcanic matter in the stratosphere to some extent blocks sunshine from reaching the Earth’s surface, the reduced solar forcing increases the probability of an El Niño event in the next year.
• This is because less sunshine means less warmth and hence a change of temperature differences between the Northern and Southern hemisphere, which in turn affects the atmospheric large-scale circulation and precipitation dynamics. 
• Advanced data analysis now reveals that large volcanic eruptions are more likely to promote the coincidence of warm El Niño events over the Pacific and Indian monsoon droughts—or, in contrast, cool La Niña events over the Pacific and Indian monsoon excess.

Arctic sea ice is being increasingly melted from below by warming Atlantic water

• What’s causing this decline in minimum sea ice extent? 

• The short answer is our changing climate. 

• But the more specific answer is that Arctic sea ice is increasingly being thinned not just by warm air from above but by ever-warmer waters from below.

• The influence of heat from the interior of the ocean has now overtaken the influence of the atmosphere.
• While atmospheric heat is the dominant reason for melting in the summer, it has little influence during the cold dark polar winter. 
• However, the ocean warms the ice from below year-round.

• This warm water, sometimes referred to as the “heat blob,” 

• originates in the Atlantic and heads northwards via an extension of the Gulf Stream, 

• entering the Arctic Ocean around Svalbard, an archipelago halfway between Norway and the North Pole. 

• The blob has already resulted in the disappearance of winter sea ice off the northern coast of Norway and north-west Russia.

Ocean acidification risks deep-sea reef collapse

• Deep-sea coral reefs face challenges as changes to ocean chemistry triggered by climate change may cause their foundations to become brittle.

• The underlying structures of the reefs—which are home to a multitude of aquatic life—could fracture as a result of increasing ocean acidity caused by rising levels of carbon dioxide.

• Hundreds of metres below the surface of the ocean in Southern California, researchers measured the lowest—therefore the most acidic—pH level ever recorded on living coral reefs. 

• The corals were then raised in the lab for one year under the same conditions.

• Scientists observed that the skeletons of dead corals, which support and hold up living corals, had become porous due to ocean acidification and rapidly become too fragile to bear the weight of the reef above them.

• Previous research has shown that ocean acidification can impact coral growth, but the new study demonstrates that porosity in corals—known as coralporosis—leads to weakening of their structure at critical locations.

Discovery of a new mass extinction

• An international team has identified a major extinction of life 233 million years ago that triggered the dinosaur takeover of the world. 

• The crisis has been called the Carnian Pluvial Episode.

• The cause was most likely massive volcanic eruptions in the Wrangellia Province of western Canada, where huge volumes of volcanic basalt was poured out and forms much of the western coast of North America.

• The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming”.

• The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about 1 million years in all. 

• The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems. 

• he shifts in climate encouraged growth of plant life, and the expansion of modern conifer forests.

• It wasn’t just dinosaurs, but also many modern groups of plants and animals also appeared at this time, including some of the first turtles, crocodiles, lizards, and the first mammals.

• It marks the start of modern-style coral reefs, as well as many of the modern groups of plankton, suggesting profound changes in the ocean chemistry and carbonate cycle.

Decreasing wildfires observed over Central Africa

• Referred to as the “fire continent” by NASA, Africa is surprisingly a crucial hot spot for blazes. 

• lobal satellite images have shown that on an average August day, it is home to at least 70 percent of the 10,000 wildfires burning worldwide and 50 percent of fire-related carbon emissions.

• However, a new observational study has revealed a decreasing burned area trend that could impact African ecosystems.

• Total decline in burned area by about 1.3 percent per year. 

• The decline, both in fire frequency and size, occurred mostly in tropical savannas and grasslands. 

• Wildfires can be hugely destructive, particularly to forest ecosystems, but also play a crucial role in maintaining ecological function and health.

• Naturally occurring fires are important for controlling vegetation growth and patterns for grasslands, savannas, and shrublands, and are integral for the maintenance of these ecosystems and supporting a large range of endemic species.