Author Archives: Pc01batchblog

> what is the reason for ice melting in antarctic ?

In the remote, alien area of the world where the Amundsen Sea meets the coast of West Antarctica, tall, frozen cliffs loom over the water. They are the edges of massive glaciers rivers of ice that spill into the ocean. In recent years, these icy rivers have been flowing and melting at an alarming rate, threatening to add a substantial amount of water to the sea that would eat away at global coastlines.

#For a long time, scientists had suspected that man-made climate change was likely causing this area of West Antarctica’s ice to thin, but they had not established a direct connection or mechanism. The issue is critical because this is where the majority of the continent’s ice loss is occurring. Now a new study published this week in Nature Geoscience appears to have solved the puzzle. A team of researchers in the U.S. and the U.K. found that global warming has caused a shift in wind patterns that are ultimately bringing more warm ocean water into contact with the region’s ice.

#Climate scientists first began to notice that all was not right with West Antarctica’s ice a couple of decades ago, but its melt proved a bit enigmatic. For the most part, air temperatures are still too cold for surface melting to explain why the ice is thinning. That fact suggested the ocean was likely the culprit yet the top layer of seawater is also too cold to thaw the ice. And while there is a deeper layer of warm ocean water that sometimes reaches the Amundsen Sea and laps away at the undersides of two giant glaciers in the region called Pine Island and Thwaites rising global temperatures were not directly warming that water.

“This is an area where the [warm] ocean waters that melt the ice have been out of contact with the atmosphere for thousands of years,” explains Paul Holland, an ice ocean scientist at the British Antarctic Survey and one of the authors of the new study. “They’re very old waters, so they wouldn’t have been [heated] by global warming.” Thus, the question for Holland and his team was if and how climate change had affected these deep ocean waters. They suspected that wind might be the missing connection.

#Holland and his colleagues combined wind data, satellite observations of sea-ice drift and climate-model simulations to understand how wind patterns near Antarctica have evolved since the 1920s (which is how far back the simulations extend) and how any changes may have affected glaciers that flow into the Amundsen Sea. They compared different simulations to parse which effects came from natural fluctuations in the climate versus anthropogenic climate change.

DONE BY

HARSHITHA GOWDA

> Threats to antarctica

1]Climate change / Global warming: 

resulting in a warming of the sea and loss of sea ice and land-based ice, this is greatest long-term threat to the region. Already some ice shelves have collapsed and ice slopes and glaciers have retreated. Oceanic acidification (from extra dissolved carbon dioxide) is already leading to the loss of some marine snails thought to have a significant part to play in the oceanic carbon cycle. The breeding populations and ranges of some penguin species have been altered.

2]Fishing, both legal and illegal:

 The world’s oceans are over-fished, the chances are that if investments into the kinds of boats and fishing gear needed for Antarctica are made, then it too will suffer this same fate. Fishing for krill could be particularly significant as these are at the bottom of many Antarctic food chains. There are already illegal fishing boats that ignore current regulations.

3]Mining:

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This is another big threat because things like oil and coal and minerals like copper and iron will not last forever. And the problem is that Antarctica has the worlds’ largest coal deposits and possibly huge stores of oil that could be used to extract tens of billions of barrels of oil. It also contains several large deposits of iron ore and even some of gold and silver. This leaves a dilemma because if the resources run out then Antarctica could well be the answer to the problems but; there are many downsides to mining in Antarctica. It would be very, very expensive because all food, water and equipment would have to be imported and then on top of that the minerals would have to be exported but to where, and how? It is a very hard problem to resolve. As well as the problem with transport as hard as that is obtaining the minerals. Most are buried beneath tonnes of ice and it would be extremely dangerous trying to retrieve them. Another point is that the minerals and coal are very low quality and not worth risking lives and money for.

DONE BY

HARSHITHA C E

> Effects of melting glaciers and sea ice loss on humans and wild life

Since the early 1900s, many glaciers around the world have been rapidly melting. Human activities are at the root of this phenomenon. Specifically, since the industrial revolution, carbon dioxide and other greenhouse gas emissions have raised temperatures, even higher in the poles, and as a result, glaciers are rapidly melting, calving off into the sea and retreating on land.

What happens in these places has consequences across the entire globe? As sea ice and glaciers melt and oceans warm, ocean currents will continue to disrupt weather patterns worldwide. Industries that thrive on vibrant fisheries will be affected as warmer waters change where and when fish spawn.

#Coastal communities will continue to face billion-dollar disaster recovery bills as flooding becomes more frequent and storms become more intense. People are not the only ones impacted. In the Arctic, as sea ice melts, wildlife like walrus are losing their home and polar bears are spending more time on land, causing higher rates of conflict between people and bears.

“Arctic sea ice has declined by more than 86,000 square kilometers — a space slightly larger than the state of South Carolina — per year,” Post said. “That’s an area of critical habitat for many species and the rate of loss is increasing.” Post added that an acceleration of this rate likely will be due, in part, to the loss the white surface provided by ice that reflects sunlight — thereby causing a cooling effect. The highly reflective ice, Post added, will be replaced by a much-less-reflective, darker surface of open water — and the effect will be accelerated warming and accelerated melting.

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“A change in population mixing could be another, indirect effect of sea-ice melting,” Post said. He explained that populations of wolves and arctic foxes that currently are isolated only during the summer could become even more isolated. A longer period of the year without ice, which promotes travel between populations, could lead to a decline in crossbreeding.

DONE BY

SHRAVANA

> Effects of melting glaciers and how it impacts on weather pattern

#Ice acts like a protective cover over the Earth and our oceans. These bright white spots reflect excess heat back into space and keep the planet cooler. In theory, the Arctic remains colder than the equator because more of the heat from the sun is reflected off the ice, back into space.

#Glaciers around the world can range from ice that is several hundred to several thousand years old and provide a scientific record of how climate has changed over time. Through their study, we gain valuable information about the extent to which the planet is rapidly warming. They provide scientists a record of how climate has changed over time.

#Today, about 10% of land area on Earth is covered with glacial ice. Almost 90% is in Antarctica, while the remaining 10% is in the Greenland ice cap.

#Rapid glacial melt in Antarctica and Greenland also influences ocean currents, as massive amounts of very cold glacial-melt water entering warmer ocean waters is slowing ocean currents. And as ice on land melts, sea levels will continue to rise.

Melting glaciers add to rising sea levels, which in turn increases coastal erosion and elevates storm surge as warming air and ocean temperatures create more frequent and intense coastal storms like hurricanes and typhoons. Specifically, the Greenland and Antarctic ice sheets are the largest contributors of global sea level rise. Right now, the Greenland ice sheet is disappearing four times faster than in 2003 and already contributes 20% of current sea level rise.

DONE BY

KEERTHANA

> Why are glaciers and sea ice melting?

#Since the early 1900s, many glaciers around the world have been rapidly melting. Human activities are at the root of this phenomenon. Specifically, since the industrial revolution, carbon dioxide and other greenhouse gas emissions have raised temperatures, even higher in the poles, and as a result, glaciers are rapidly melting, calving off into the sea and retreating on land.

#Even if we significantly curb emissions in the coming decades, more than a third of the world’s remaining glaciers will melt before the year 2100. When it comes to sea ice, 95% of the oldest and thickest ice in the arctic is already gone.

#Scientists project that if emissions continue to rise unchecked, the Arctic could be ice free in the summer as soon as the year 2040 as ocean and air temperatures continue to rise rapidly.

Sea ice forms and melts strictly in the ocean whereas glaciers are formed on land. Icebergs are chunks of glacial ice that break off glaciers and fall into the ocean.

When glaciers melt, because that water is stored on land, the runoff significantly increases the amount of water in the ocean, contributing to global sea level rise.

Sea ice, on the other hand, is often compared to ice cubes in a glass of water: when it melts, it does not directly change the level of water in the glass. Instead, depleting Arctic sea ice triggers a host of other devastating consequences—from depleting available ice on which walrus can haul out or polar bears hunt to changing weather systems around the world by altering the pattern of the Jet stream.

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Melting glaciers add to rising sea levels, which in turn increases coastal erosion and elevates storm surge as warming air and ocean temperatures create more frequent and intense coastal storms like hurricanes and typhoons. Specifically, the Greenland and Antarctic ice sheets are the largest contributors of global sea level rise. Right now, the Greenland ice sheet is disappearing four times faster than in 2003 and already contributes 20% of current sea level rise.

DONE BY

ABHIRAJ

> what is ice melting antarctic?

There has been lots of talk lately about Antarctica and whether or not the continent’s giant ice sheet is melting. One new paper¹, which states there has been less surface melting recently than in past years, has been cited as “proof” that there’s no global warming. Other evidence that the amount of sea ice around Antarctica seems to be increasing slightly is being used in the same way. But both of these data points are misleading.

#Gravity data collected from space using NASA’s Grace satellite show that Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002. The latest data reveals that Antarctica is losing ice at an accelerating rate, too. 

#Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 2 kilometers (1.2 miles), higher than the American Colorado Plateau.

#There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 2 kilometers (1.2 miles) thick. If all of this ice melted, it would raise global sea level by about 60 meters (197 feet). But little, if any, surface warming is occurring over East Antarctica.

# Radar- and laser-based satellite data show a little mass loss at the edges of East Antarctica, which is being partly offset by accumulation of snow in the interior, although a very recent result from the NASA/German Aerospace Center’s Gravity Recovery and Climate Experiment (Grace) suggests that since 2006 there has been more ice loss from East Antarctica than previously thought. Overall, not much is going on in East Antarctica yet.

DONE BY

K . SUDHEER KUMAR

> Countries Most Affected by Global Warming

#Global warming is now in our lives, according to climate scientists, rising polar temperatures and the rapid melting of glaciers have already begun to affect North America, Europe, and Asia, where millions of people live.

#Explaining that snowstorms, intense winter heat, and flood disasters are related to rising temperatures, scientists explain that important changes have taken place in the atmosphere and that this is especially affecting the regions where human beings live as crowds.

Animals,insects,and plants already threatened by habitat destruction and pollution will fare even worse . only a small amount of warming will kill 70 to 90 percent of the world’s coral reefs ; upto half of plant and animal species in the world’s most naturally rich areas could face extinction.

Nowadays, global climate change refers to the increase in the average surface temperatures of the Earth and the changes in climate as a result of the rapid increase in the greenhouse effect of greenhouse gas accumulations released into the atmosphere by human activities such as burning fossil fuels, land use changes, deforestation, and industrial processes.

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The heat energy held on earth and in the atmosphere is dispersed in the earth by the atmosphere and the ocean circulation, and it is given back to the atmosphere as long-wave radiation. Part of this is absorbed by clouds and greenhouse gases regulating the greenhouse effect and released back by the atmosphere. In this way, the Earth’s surface and the lower atmosphere become hot. This process is the natural greenhouse effect, which allows the earth to warm more than expectations and regulate the heat balance.

DONE BY

KASUMURTHY VAMSI

> MEASURES TO REDUSE GREEN HOUSE EFFECT ON EARTH

One of the best ways to reduce greenhouse gas emissions is to limit energy consumption. Using energy in many of its forms comes with the negative externality of releasing greenhouse gases into the atmosphere.

# For instance, electricity is commonly produced by coal power plants which burn goal and release CO2 into the air. Limiting the use of devices which use fossil fuels for energy is especially important cars, lawn mowers, chainsaws, and other gasoline and diesel powered devices account for a large portion of the greenhouse gasses emitted by humans.

# Finding clean energy alternatives is a good way to limit the greenhouse effect while still getting the energy you need. Efficient hybrid cars and green electricity sources, such as solar and wind power, help reduce greenhouse emissions.

*USE LESS ENERGY

#Taking steps to use less electricity, especially when it comes from burning coal or gas, can take a big dent out of greenhouse gas emissions. Worldwide, electricity use is responsible for a quarter of all emissions. 

#Some steps that you can take to use less electricity are simple and save money – like replacing incandescent light bulbs with LED bulbs that use less electricity, adding insulation to your home, and setting the thermostat lower in the winter and higher in the summer, especially when no one is home.

#There are also new technologies that help keep buildings energy efficient, such as glass that reflects heat, low-flow water fixtures, smart thermostats, and new air conditioning technology with refrigerants that don’t cause warming. In urban and suburban environments, green or cool roofs can limit the amount of heat that gets into buildings during hot days and help decrease the urban heat island effect.

*Generate electricity without emissions

Renewable energy sources include solar energy, geothermal, wind turbines, ocean wave and tidal energy, waste and biomass energy, and hydropower. Because they do not burn fossil fuels, these renewable energy sources do not release greenhouse gases into the atmosphere as they generate electricity.

#Nuclear energy also creates no greenhouse gas emissions, so it can be thought of as a solution to climate change. However, it does generate radioactive waste that needs long-term, secure storage.

#Today, the amount of electricity that comes from renewable energy is growing. A few countries, such as Iceland and Costa Rica, now get nearly all of their electricity from renewable energy. In many other countries, the percentage of electricity from renewable sources is currently small (5-10%) but growing.

DONE BY

AANANDALA LAXMI NIVAS

> ROLE OF HUMANS IN IMPACTING THE GREEN HOUSE EFFECT

Throughout most of human history, and certainly, before human beings emerged as a dominant species throughout the world, all climate changes were the direct result of natural forces like solar cycles and volcanic eruptions.

# Along with the Industrial revolution and an increasing population size, humans began altering climates with ever-growing influence, and eventually surpassed natural causes in their ability to change the climate. Human-caused global climate change is primarily due to the release, through our activities, of green house gases.

#Greenhouse gases are released into the air, where they persist for a long period at high altitude and absorb reflected sunlight. They then warm the atmosphere, the surface of the land, and the oceans. Many of our activities contribute greenhouse gases to the atmosphere.

A stylized representation of the natural greenhouse effect. Most of the sun’s radiation reaches the Earth’s surface. Naturally occurring heat-trapping gases, including water vapor, carbon dioxide, methane, and nitrous oxide, do not absorb the short-wave energy from the sun but do absorb the long-wave energy re-radiated from the Earth, keeping the planet much warmer than it would be otherwise.

# In this stylized representation of the human-intensified greenhouse effect, human activities, predominantly the burning of fossil fuels (coal, oil, and gas), are increasing levels of carbon dioxide and other heat-trapping gases, increasing the natural greenhouse effect and thus Earth’s temperature.

DONE BY

DASARI KARTHIJA

Global warming is the phenomenon of a gradual increase in the temperature near the earth’s surface. This phenomenon has been observed over the past one or two centuries.

The global warming happens because the natural rotation of the sun that changes the intensity of sunlight and moving closer to the earth. Another cause of global warming is greenhouse gases.Finally, methane is another issue that causes global warming. Methane is also a greenhouse gas

#This change has disturbed the climatic pattern of the earth. However, the concept of global warming is quite controversial but the scientists have provided relevant data in support of the fact that the temperature of the earth is rising constantly.

WHAT IS GREEN HOUSE EFFECT ?

The greenhouse effect is the way in which heat is trapped close to the surface of the Earth by “greenhouse gases.” These heat-trapping gases can be thought of as a blanket wrapped around the Earth, which keeps it toastier than it would be without them. Greenhouse gases include carbon dioxide, methane and nitrous oxides.

#Greenhouse gases arise naturally, and are part of the make-up of our atmosphere. Earth is sometimes called the “Goldilocks” planet – it’s not too hot, not too cold, and the conditions are just right to allow life, including us, to flourish.

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Same is the case in the earth’s atmosphere. During the day the sun heats up the earth’s atmosphere. At night, when the earth cools down the heat is radiated back into the atmosphere.

#During this process, the heat is absorbed by the greenhouse gases in the earth’s atmosphere. This is what makes the surface of the earth warmer, that makes the survival of living beings on earth possible.

#However, due to the increased levels of greenhouse gases, the temperature of the earth has increased considerably. This has led to several drastic effects.

CAUSES OF GREEN HOUSE EFFECT :

NATURAL CAUSES :

1. Some components that are present on the Earth naturally produce greenhouse gases. For example, carbon dioxide is present in the oceans, decaying of plants due to forest fires and the manure of some animals produces methane, and nitrogen oxide is present in water and soil.
2.Water Vapour raises the temperature by absorbing energy when there is a rise in the humidity.
3.Humans and animals breathe oxygen and release carbon dioxide in the atmosphere.

MAN-MADE CAUSES :

1.Burning of fossil fuels such as oil and coal emits carbon dioxide in the atmosphere which causes an excessive greenhouse effect. Also, while digging a coal mine or an oil well, methane is released from the Earth, which pollutes it.
2.Trees with the help of the process of photosynthesis absorb the carbon dioxide and release oxygen. Due to deforestation the carbon dioxide level is continuously increasing. This is also a major cause of the increase in the greenhouse effect.
3.In order to get maximum yield, the farmers use artificial nitrogen in their fields. This releases nitrogen oxide in the atmosphere.
4.Industries release harmful gases in the atmosphere like methane, carbon dioxide, and fluorine gas. These also enhance global warming.

DONE BY

NAGARURU NEHA