346
Common Forum/Request/Suggestions / Re: কলার খোসার কিছু প্রয়োজনীয় ব্যবহার
« on: March 10, 2016, 02:33:22 PM »
Useful information!!
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347
Common Forum/Request/Suggestions / Re: Knowledgebase: About Library
« on: March 10, 2016, 02:32:37 PM »
very useful information!
348
Geography / Fossil fuel use must fall twice as fast as thought to contain global warming -4
« on: March 10, 2016, 02:31:44 PM »
Complex calculations
But Dr Rogelj and his colleagues found that a significant cause of variation was simply a consequence of the different assumptions and methodologies inherent in such complex calculations.
So the researchers have re-examined both the options and the approaches, and have worked out a global figure that, they suggest, could be relevant to “real-world policy”.
It takes into account the consequences of all human activity, and it embraces detailed outlines of possible low-carbon choices. It also offers, they say, a 66% chance of staying within the internationally-agreed limit.
“We now better understand the carbon budget for keeping global warming below 2C,” Dr Rogelj says. “This carbon budget is very important to know because it defines how much carbon dioxide we are allowed to release into the atmosphere, ever.
“We have figured out that this budget is at the low end of what studies indicated before, and if we don’t start reducing our emissions immediately, we will blow it in a few decades.”
But Dr Rogelj and his colleagues found that a significant cause of variation was simply a consequence of the different assumptions and methodologies inherent in such complex calculations.
So the researchers have re-examined both the options and the approaches, and have worked out a global figure that, they suggest, could be relevant to “real-world policy”.
It takes into account the consequences of all human activity, and it embraces detailed outlines of possible low-carbon choices. It also offers, they say, a 66% chance of staying within the internationally-agreed limit.
“We now better understand the carbon budget for keeping global warming below 2C,” Dr Rogelj says. “This carbon budget is very important to know because it defines how much carbon dioxide we are allowed to release into the atmosphere, ever.
“We have figured out that this budget is at the low end of what studies indicated before, and if we don’t start reducing our emissions immediately, we will blow it in a few decades.”
349
Geography / Fossil fuel use must fall twice as fast as thought to contain global warming -3
« on: March 10, 2016, 02:30:55 PM »
The global carbon budget is really the balance between what animals emit – in this context, the word animals includes humans with cars and aeroplanes and factories – and what plants and algae can absorb. So the calculations are bedevilled by uncertainties about forests, grasslands and oceans.
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To make things simpler, climate scientists translate the target into the billions of tons of carbon dioxide that, ideally, may be released into the atmosphere from 2015 onwards. Even these, however, are estimates.
There is general agreement that a limit of 590 bn tons would safely keep the world from overheating in ways that would impose ever greater strains on human society. The argument is about the upper limit of such estimates.
Dr Rogelj says: “In order to have a reasonable chance of keeping global warming below 2C, we can only emit a certain amount of carbon dioxide, ever. That’s our carbon budget.
“This has been understood for about a decade, and the physics behind this concept are well understood, but many different factors can lead to carbon budgets that are either slightly smaller or slightly larger. We wanted to understand these differences, and to provide clarity on the issue for policymakers and the public.
“This study shows that, in some cases, we have been overestimating the budget by 50 to more than 200%. At the high end, this is a difference of more than 1,000 billion tons of carbon dioxide.”
The same study takes a closer look at why estimates of the “safe” level of emissions have varied so widely.
One complicating factor has been, of course, uncertainty about what humans might do, and another has been about the other more transient greenhouse gases, such as methane and the oxides of nitrogen.
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Although short-lived and released in smaller quantities, some of these are potentially far more potent than carbon dioxide as an influence on planetary temperatures.
Advertisement
To make things simpler, climate scientists translate the target into the billions of tons of carbon dioxide that, ideally, may be released into the atmosphere from 2015 onwards. Even these, however, are estimates.
There is general agreement that a limit of 590 bn tons would safely keep the world from overheating in ways that would impose ever greater strains on human society. The argument is about the upper limit of such estimates.
Dr Rogelj says: “In order to have a reasonable chance of keeping global warming below 2C, we can only emit a certain amount of carbon dioxide, ever. That’s our carbon budget.
“This has been understood for about a decade, and the physics behind this concept are well understood, but many different factors can lead to carbon budgets that are either slightly smaller or slightly larger. We wanted to understand these differences, and to provide clarity on the issue for policymakers and the public.
“This study shows that, in some cases, we have been overestimating the budget by 50 to more than 200%. At the high end, this is a difference of more than 1,000 billion tons of carbon dioxide.”
The same study takes a closer look at why estimates of the “safe” level of emissions have varied so widely.
One complicating factor has been, of course, uncertainty about what humans might do, and another has been about the other more transient greenhouse gases, such as methane and the oxides of nitrogen.
Advertisement
Although short-lived and released in smaller quantities, some of these are potentially far more potent than carbon dioxide as an influence on planetary temperatures.
350
Geography / Fossil fuel use must fall twice as fast as thought to contain global warming -2
« on: March 10, 2016, 02:30:14 PM »
Available levels
In effect, that halves the levels of diesel and petrol available for petrol tanks, coal for power stations, and natural gas for central heating and cooking available to humankind before the global average temperature – already 1C higher than it was at the start of the Industrial Revolution – reaches the notional 2C mark long agreed internationally as being the point of no return for the planet.
In fact, the UN Framework Convention on Climate Change summit in Paris agreed a target “well below” 2C, in recognition of ominous projections − one of which was that, at such planetary temperatures, sea levels would rise high enough to submerge several small island states.
The Nature Climate Change paper is a restatement of a problem that has been clear for decades. Carbon dioxide proportions in the atmosphere are linked to planetary surface temperatures and, as they rise, so does average temperature. For most of human history, these proportions oscillated around 280 parts per million.
The global exploitation, on a massive scale, of fossil fuels drove the expansion of agriculture, the growth of economies, a sevenfold growth in human population, a sea level rise of 14cms, and a temperature rise of, so far, 1C.
To stop temperatures increasing another 3C or more and sea levels rising by more than a metre, humans have to reduce fossil fuel emissions. By how much these must be reduced is difficult to calculate.
In effect, that halves the levels of diesel and petrol available for petrol tanks, coal for power stations, and natural gas for central heating and cooking available to humankind before the global average temperature – already 1C higher than it was at the start of the Industrial Revolution – reaches the notional 2C mark long agreed internationally as being the point of no return for the planet.
In fact, the UN Framework Convention on Climate Change summit in Paris agreed a target “well below” 2C, in recognition of ominous projections − one of which was that, at such planetary temperatures, sea levels would rise high enough to submerge several small island states.
The Nature Climate Change paper is a restatement of a problem that has been clear for decades. Carbon dioxide proportions in the atmosphere are linked to planetary surface temperatures and, as they rise, so does average temperature. For most of human history, these proportions oscillated around 280 parts per million.
The global exploitation, on a massive scale, of fossil fuels drove the expansion of agriculture, the growth of economies, a sevenfold growth in human population, a sea level rise of 14cms, and a temperature rise of, so far, 1C.
To stop temperatures increasing another 3C or more and sea levels rising by more than a metre, humans have to reduce fossil fuel emissions. By how much these must be reduced is difficult to calculate.
351
Geography / Fossil fuel use must fall twice as fast as thought to contain global warming 1
« on: March 10, 2016, 02:28:49 PM »
Climate scientists have bad news for governments, energy companies, motorists, passengers and citizens everywhere in the world: to contain global warming to the limits agreed by 195 nations in Paris last December, they will have to cut fossil fuel combustion at an even faster rate than anybody had predicted.
Joeri Rogelj, research scholar at the International Institute for Applied Systems Analysis in Austria, and European and Canadian colleagues propose in Nature Climate Change that all previous estimates of the quantities of carbon dioxide that can be released into the atmosphere before the thermometer rises to potentially catastrophic levels are too generous.
Instead of a range of permissible emissions estimates that ranged up to 2,390 bn tons from 2015 onwards, the very most humans could release would be 1,240 bn tons.
Joeri Rogelj, research scholar at the International Institute for Applied Systems Analysis in Austria, and European and Canadian colleagues propose in Nature Climate Change that all previous estimates of the quantities of carbon dioxide that can be released into the atmosphere before the thermometer rises to potentially catastrophic levels are too generous.
Instead of a range of permissible emissions estimates that ranged up to 2,390 bn tons from 2015 onwards, the very most humans could release would be 1,240 bn tons.
352
Animals and Pets / why is 2016 smashing heat records part 4
« on: March 10, 2016, 02:26:19 PM »
Steffen says quantifying the relative contributions of El Niño and climate change on a monthly or even annual basis cannot help to answer how fast the world is warming. Only trends over 30 years really matter.
But the pile up of records we have had in the early part of this century are significant. All things being constant, record hot years should occur once every 150 years. Yet 1998, 2005, 2010, 2014 and 2015 have all been record breakers.
A study published in January found that even without last year’s mammoth anomaly such a run was 600 to 130,000 times more likely to have occurred with human interference than without.
“The fact that you are getting records so close, one after the other is really striking. And that is symptomatic of that long-term trend,” said Steffen.
But while they may be poor signals for long-term climate change, record hot months and years do have an immediate and tangible impact.
“It’s making heat waves worse. Here in Australia it bumps up the bushfire danger weather really fast. It tends to lead to drier conditions in our part of the world. These things are exacerbated by El Niños, so I don’t want to downplay the importance of them for human suffering,” said Steffen.
But the pile up of records we have had in the early part of this century are significant. All things being constant, record hot years should occur once every 150 years. Yet 1998, 2005, 2010, 2014 and 2015 have all been record breakers.
A study published in January found that even without last year’s mammoth anomaly such a run was 600 to 130,000 times more likely to have occurred with human interference than without.
“The fact that you are getting records so close, one after the other is really striking. And that is symptomatic of that long-term trend,” said Steffen.
But while they may be poor signals for long-term climate change, record hot months and years do have an immediate and tangible impact.
“It’s making heat waves worse. Here in Australia it bumps up the bushfire danger weather really fast. It tends to lead to drier conditions in our part of the world. These things are exacerbated by El Niños, so I don’t want to downplay the importance of them for human suffering,” said Steffen.
353
Animals and Pets / why is 2016 smashing heat records part 3
« on: March 10, 2016, 02:25:30 PM »
“The bottom line is that the contributions of the current El Niño and wind patterns to the very warm conditions globally over the last couple of months are relatively small compared to the anthropogenically driven increase in global temperature since pre-industrial times,” he added.
Steffen said the definitive assessment of this El Niño and its effect on the world’s temperature would only be possible once the event had run its course (it has now peaked and is expected to end in the second quarter of this year). But he agreed that past El Niño cycles could be an appropriate guide for the order of magnitude of the effect.
The picture becomes less clear cut when we talk about monthly records. Even weather trends can have small effects on the monthly average temperature, said Knight. The effect of El Niño traditionally increases as it dies, so Mann believes it may have added more than the “nominal” o.1C during the past three months.
In the Arctic, the effect of El Niño is poorly understood but likely to be weak, said Knight. “Given that the Arctic has been very warm for a number of years, with record low sea ice, it is more likely that the warmth there currently is part of a long-term trend rather than the response to a episodic event like El Niño.”
Steffen said the definitive assessment of this El Niño and its effect on the world’s temperature would only be possible once the event had run its course (it has now peaked and is expected to end in the second quarter of this year). But he agreed that past El Niño cycles could be an appropriate guide for the order of magnitude of the effect.
The picture becomes less clear cut when we talk about monthly records. Even weather trends can have small effects on the monthly average temperature, said Knight. The effect of El Niño traditionally increases as it dies, so Mann believes it may have added more than the “nominal” o.1C during the past three months.
In the Arctic, the effect of El Niño is poorly understood but likely to be weak, said Knight. “Given that the Arctic has been very warm for a number of years, with record low sea ice, it is more likely that the warmth there currently is part of a long-term trend rather than the response to a episodic event like El Niño.”
354
Animals and Pets / why is 2016 smashing heat records part 2
« on: March 10, 2016, 02:24:46 PM »
These tumbling temperature records are often accompanied in media reports by the caveat that we are experiencing a particularly strong El Niño - perhaps the largest in history. But should El Niño and climate change be given equal billing?
No, according to Professor Michael Mann, the director of Penn State Earth System Science Centre. He said it was possible to look back over the temperature records and assess the impact of an El Niño on global temperatures.
“A number of folks have done this,” he said, “and come to the conclusion it was responsible for less than 0.1C of the anomalous warmth. In other words, we would have set an all-time global temperature record [in 2015] even without any help from El Niño.”
Global surface temperature is the major yardstick used to track how we are changing the climate. It is the average the UN Paris agreement refers to.
But the atmosphere doesn’t stop at the surface. In fact 93% of the extra energy trapped by the greenhouse gases humans have emitted gets sunk into the oceans – just 1% ends up in the atmosphere where temperature is most often and most thoroughly measured. During El Niño, which occurs every three to six years, currents in the Pacific Ocean bring warm water to the surface and heat up the air.
Jeff Knight from the Met Office’s Hadley Centre, said their modelling set the additional heat from a big El Niño, like the current one, at about 0.2C. He said wind patterns in the northern hemisphere had added another 0.1C to recent monthly readings.
No, according to Professor Michael Mann, the director of Penn State Earth System Science Centre. He said it was possible to look back over the temperature records and assess the impact of an El Niño on global temperatures.
“A number of folks have done this,” he said, “and come to the conclusion it was responsible for less than 0.1C of the anomalous warmth. In other words, we would have set an all-time global temperature record [in 2015] even without any help from El Niño.”
Global surface temperature is the major yardstick used to track how we are changing the climate. It is the average the UN Paris agreement refers to.
But the atmosphere doesn’t stop at the surface. In fact 93% of the extra energy trapped by the greenhouse gases humans have emitted gets sunk into the oceans – just 1% ends up in the atmosphere where temperature is most often and most thoroughly measured. During El Niño, which occurs every three to six years, currents in the Pacific Ocean bring warm water to the surface and heat up the air.
Jeff Knight from the Met Office’s Hadley Centre, said their modelling set the additional heat from a big El Niño, like the current one, at about 0.2C. He said wind patterns in the northern hemisphere had added another 0.1C to recent monthly readings.
355
Animals and Pets / Why is 2016 smashing heat records part 1
« on: March 10, 2016, 02:23:43 PM »
Yet another global heat record has been beaten. It appears January 2016 - the most abnormally hot month in history, according to Nasa - will be comprehensively trounced once official figures come in for February.
Initial satellite measurements, compiled by Eric Holthaus at Slate, put February’s anomaly from the pre-industrial average between 1.15C and 1.4C. The UN Paris climate agreement struck in December seeks to limit warming to 1.5C if possible.
“Even the lower part of that range is extraordinary,” said Will Steffen, an emeritus professor of climate science at Australian National University and a councillor at Australia’s Climate Council.
It appears that on Wednesday, the northern hemisphere even slipped above the milestone 2C average for the first time in recorded history. This is the arbitrary limit above which scientists believe global temperature rise will be “dangerous”.
The Arctic in particular experienced terrific warmth throughout the winter. Temperatures at the north pole approached 0C in late December – 30C to 35C above average.
Mark Serreze, the director of the US National Snow and Ice Data Centre, described the conditions as “absurd”.
“The heat has been unrelenting over the entire season,” he said. “I’ve been studying Arctic climate for 35 years and have never seen anything like this before”.
All this weirdness follows the record-smashing year of 2015, which was 0.9C above the 20th century average. This beat the previous record warmth of 2014 by 0.16C.
Initial satellite measurements, compiled by Eric Holthaus at Slate, put February’s anomaly from the pre-industrial average between 1.15C and 1.4C. The UN Paris climate agreement struck in December seeks to limit warming to 1.5C if possible.
“Even the lower part of that range is extraordinary,” said Will Steffen, an emeritus professor of climate science at Australian National University and a councillor at Australia’s Climate Council.
It appears that on Wednesday, the northern hemisphere even slipped above the milestone 2C average for the first time in recorded history. This is the arbitrary limit above which scientists believe global temperature rise will be “dangerous”.
The Arctic in particular experienced terrific warmth throughout the winter. Temperatures at the north pole approached 0C in late December – 30C to 35C above average.
Mark Serreze, the director of the US National Snow and Ice Data Centre, described the conditions as “absurd”.
“The heat has been unrelenting over the entire season,” he said. “I’ve been studying Arctic climate for 35 years and have never seen anything like this before”.
All this weirdness follows the record-smashing year of 2015, which was 0.9C above the 20th century average. This beat the previous record warmth of 2014 by 0.16C.
356
Animals and Pets / Hotter planet spells harder rains to come- study
« on: March 10, 2016, 02:19:38 PM »
Severe rainfall has increased throughout the world’s wettest and driest regions and is set to intensify this century, new research suggests.
Since 1950, daily extremes have risen 1-2% a decade, a study published in journal Nature said on Monday.
That trend is expected to last until at least 2100, prompting emergency planners to take precautions against flash flooding. Dry regions such as Saharan Africa, the Arabian Peninsula or Australia, whose parched soil poorly absorbs excess water, would be most vulnerable.
Global warming increases the amount of water vapour in the atmosphere, leading to heavier downpours.
The study led by Markus Donat at the University of New South Wales in Australia couldn’t say exactly where extreme rainfall would occur, but underlined the heightened risks. Tropical regions were most uncertain.
Floods made up almost half of all weather-related disasters in the last two decades, according to the UN office for disaster risk reduction. They affected 2.3 billion people, 95% of whom were in Asia.
Since 1950, daily extremes have risen 1-2% a decade, a study published in journal Nature said on Monday.
That trend is expected to last until at least 2100, prompting emergency planners to take precautions against flash flooding. Dry regions such as Saharan Africa, the Arabian Peninsula or Australia, whose parched soil poorly absorbs excess water, would be most vulnerable.
Global warming increases the amount of water vapour in the atmosphere, leading to heavier downpours.
The study led by Markus Donat at the University of New South Wales in Australia couldn’t say exactly where extreme rainfall would occur, but underlined the heightened risks. Tropical regions were most uncertain.
Floods made up almost half of all weather-related disasters in the last two decades, according to the UN office for disaster risk reduction. They affected 2.3 billion people, 95% of whom were in Asia.
357
Common Forum/Request/Suggestions / Re: অল্প সময়ের মধ্যে খুলবে ফেসবুক: পলক
« on: March 10, 2016, 02:06:09 PM »
Good news
358
Common Forum/Request/Suggestions / Re: যেভাবে এলো বাঙালির বংশ পদবী!
« on: March 10, 2016, 02:05:36 PM »
Very important information to know our root
359
Common Forum/Request/Suggestions / Re: প্রযুক্তি বাজারগুলোর বিক্রি বেড়েছে
« on: March 10, 2016, 02:03:48 PM »
thanks for sharing this! 
360
Hajj / Re: মাত্র ৬৫ হাজার টাকায় ১০ রাতের ওমরাহ হজ!
« on: March 10, 2016, 02:02:55 PM »
thanks for sharing!