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Tuesday 1 March 2016
Wednesday 3 February 2016
WORLD CLIMATE CHANGE
Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change
may refer to a change in average weather conditions, or in the time
variation of weather around longer-term average conditions (i.e., more
or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming"
Scientists actively work to understand past and future climate by using observations and theoretical models. A climate record—extending deep into the Earth's past—has been assembled, and continues to be built up, based on geological evidence from borehole temperature profiles, cores removed from deep accumulations of ice, floral and faunal records, glacial and periglacial processes, stable-isotope and other analyses of sediment layers, and records of past sea levels. More recent data are provided by the instrumental record. General circulation models, based on the physical sciences, are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change.
In the context of climate variation, anthropogenic factors are human activities which affect the climate. The scientific consensus on climate change is "that climate is changing and that these changes are in large part caused by human activities," and it "is largely irreversible."
Glaciers grow and shrink due both to natural variability and external forcings. Variability in temperature, precipitation, and englacial and subglacial hydrology can strongly determine the evolution of a glacier in a particular season. Therefore, one must average over a decadal or longer time-scale and/or over many individual glaciers to smooth out the local short-term variability and obtain a glacier history that is related to climate.
A world glacier inventory has been compiled since the 1970s, initially based mainly on aerial photographs and maps but now relying more on satellites. This compilation tracks more than 100,000 glaciers covering a total area of approximately 240,000 km2, and preliminary estimates indicate that the remaining ice cover is around 445,000 km2. The World Glacier Monitoring Service collects data annually on glacier retreat and glacier mass balance. From this data, glaciers worldwide have been found to be shrinking significantly, with strong glacier retreats in the 1940s, stable or growing conditions during the 1920s and 1970s, and again retreating from the mid-1980s to present.
The most significant climate processes since the middle to late Pliocene (approximately 3 million years ago) are the glacial and interglacial cycles. The present interglacial period (the Holocene) has lasted about 11,700 years. Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level changes helped create the climate. Other changes, including Heinrich events, Dansgaard–Oeschger events and the Younger Dryas, however, illustrate how glacial variations may also influence climate without the orbital forcing.
Glaciers leave behind moraines that contain a wealth of material—including organic matter, quartz, and potassium that may be dated—recording the periods in which a glacier advanced and retreated. Similarly, by tephrochronological techniques, the lack of glacier cover can be identified by the presence of soil or volcanic tephra horizons whose date of deposit may also be ascertained.
Climatological temperatures substantially affect cloud cover and precipitation. For instance, during the Last Glacial Maximum of 18,000 years ago, thermal-driven evaporation from the oceans onto continental landmasses was low, causing large areas of extreme desert, including polar deserts (cold but with low rates of cloud cover and precipitation). In contrast, the world's climate was cloudier and wetter than today near the start of the warm Atlantic Period of 8000 years ago.
Estimated global land precipitation increased by approximately 2% over the course of the 20th century, though the calculated trend varies if different time endpoints are chosen, complicated by ENSO and other oscillations, including greater global land cloud cover precipitation in the 1950s and 1970s than the later 1980s and 1990s despite the positive trend over the century overall. Similar slight overall increase in global river runoff and in average soil moisture has been perceived.
Similarly, the historical abundance of various fish species has been found to have a substantial relationship with observed climatic conditions. Changes in the primary productivity of autotrophs in the oceans can affect marine food webs.
For more visit Wikipedia
Scientists actively work to understand past and future climate by using observations and theoretical models. A climate record—extending deep into the Earth's past—has been assembled, and continues to be built up, based on geological evidence from borehole temperature profiles, cores removed from deep accumulations of ice, floral and faunal records, glacial and periglacial processes, stable-isotope and other analyses of sediment layers, and records of past sea levels. More recent data are provided by the instrumental record. General circulation models, based on the physical sciences, are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change.
Human influences
In the context of climate variation, anthropogenic factors are human activities which affect the climate. The scientific consensus on climate change is "that climate is changing and that these changes are in large part caused by human activities," and it "is largely irreversible."
Physical evidence
Evidence for climatic change is taken from a variety of sources that can be used to reconstruct past climates. Reasonably complete global records of surface temperature are available beginning from the mid-late 19th century. For earlier periods, most of the evidence is indirect—climatic changes are inferred from changes in proxies, indicators that reflect climate, such as vegetation, ice cores, dendrochronology, sea level change, and glacial geology.Temperature measurements and proxies
The instrumental temperature record from surface stations was supplemented by radiosonde balloons, extensive atmospheric monitoring by the mid-20th century, and, from the 1970s on, with global satellite data as well. The 18O/16O ratio in calcite and ice core samples used to deduce ocean temperature in the distant past is an example of a temperature proxy method, as are other climate metrics noted in subsequent categories.Glaciers
Glaciers are considered among the most sensitive indicators of climate change. Their size is determined by a mass balance between snow input and melt output. As temperatures warm, glaciers retreat unless snow precipitation increases to make up for the additional melt; the converse is also true.Glaciers grow and shrink due both to natural variability and external forcings. Variability in temperature, precipitation, and englacial and subglacial hydrology can strongly determine the evolution of a glacier in a particular season. Therefore, one must average over a decadal or longer time-scale and/or over many individual glaciers to smooth out the local short-term variability and obtain a glacier history that is related to climate.
A world glacier inventory has been compiled since the 1970s, initially based mainly on aerial photographs and maps but now relying more on satellites. This compilation tracks more than 100,000 glaciers covering a total area of approximately 240,000 km2, and preliminary estimates indicate that the remaining ice cover is around 445,000 km2. The World Glacier Monitoring Service collects data annually on glacier retreat and glacier mass balance. From this data, glaciers worldwide have been found to be shrinking significantly, with strong glacier retreats in the 1940s, stable or growing conditions during the 1920s and 1970s, and again retreating from the mid-1980s to present.
The most significant climate processes since the middle to late Pliocene (approximately 3 million years ago) are the glacial and interglacial cycles. The present interglacial period (the Holocene) has lasted about 11,700 years. Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level changes helped create the climate. Other changes, including Heinrich events, Dansgaard–Oeschger events and the Younger Dryas, however, illustrate how glacial variations may also influence climate without the orbital forcing.
Glaciers leave behind moraines that contain a wealth of material—including organic matter, quartz, and potassium that may be dated—recording the periods in which a glacier advanced and retreated. Similarly, by tephrochronological techniques, the lack of glacier cover can be identified by the presence of soil or volcanic tephra horizons whose date of deposit may also be ascertained.
Of most concern in these anthropogenic factors is the increase in CO2 levels due to emissions from fossil fuel combustion, followed by aerosols (particulate matter in the atmosphere) and the CO2 released by cement manufacture. Other factors, including land use, ozone depletion, animal agriculture and deforestation, are also of concern in the roles they play – both separately and in conjunction with other factors – in affecting climate, microclimate, and measures of climate variables.“Science has made enormous inroads in understanding climate change and its causes, and is beginning to help develop a strong understanding of current and potential impacts that will affect people today and in coming decades. This understanding is crucial because it allows decision makers to place climate change in the context of other large challenges facing the nation and the world. There are still some uncertainties, and there always will be in understanding a complex system like Earth’s climate. Nevertheless, there is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities. While much remains to be learned, the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations.”
— United States National Research Council, Advancing the Science of Climate Change
Arctic sea ice loss
Main articles: Arctic sea ice decline and Climate change in the Arctic
The decline in Arctic sea ice, both in extent and thickness, over the
last several decades is further evidence for rapid climate change.
Sea ice is frozen seawater that floats on the ocean surface. It covers
millions of square miles in the polar regions, varying with the seasons.
In the Arctic, some sea ice remains year after year, whereas almost all Southern Ocean
or Antarctic sea ice melts away and reforms annually. Satellite
observations show that Arctic sea ice is now declining at a rate of 13.3
percent per decade, relative to the 1981 to 2010 average.Vegetation
A change in the type, distribution and coverage of vegetation may occur given a change in the climate. Some changes in climate may result in increased precipitation and warmth, resulting in improved plant growth and the subsequent sequestration of airborne CO2. A gradual increase in warmth in a region will lead to earlier flowering and fruiting times, driving a change in the timing of life cycles of dependent organisms. Conversely, cold will cause plant bio-cycles to lag. Larger, faster or more radical changes, however, may result in vegetation stress, rapid plant loss and desertification in certain circumstances. An example of this occurred during the Carboniferous Rainforest Collapse (CRC), an extinction event 300 million years ago. At this time vast rainforests covered the equatorial region of Europe and America. Climate change devastated these tropical rainforests, abruptly fragmenting the habitat into isolated 'islands' and causing the extinction of many plant and animal species.Pollen analysis
Palynology is the study of contemporary and fossil palynomorphs, including pollen. Palynology is used to infer the geographical distribution of plant species, which vary under different climate conditions. Different groups of plants have pollen with distinctive shapes and surface textures, and since the outer surface of pollen is composed of a very resilient material, they resist decay. Changes in the type of pollen found in different layers of sediment in lakes, bogs, or river deltas indicate changes in plant communities. These changes are often a sign of a changing climate. As an example, palynological studies have been used to track changing vegetation patterns throughout the Quaternary glaciations and especially since the last glacial maximum.Cloud cover and precipitation
Past precipitation can be estimated in the modern era with the global network of precipitation gauges. Surface coverage over oceans and remote areas is relatively sparse, but, reducing reliance on interpolation, satellite clouds and precipitation data has been available since the 1970s. Quantification of climatological variation of precipitation in prior centuries and epochs is less complete but approximated using proxies such as marine sediments, ice cores, cave stalagmites, and tree rings.Climatological temperatures substantially affect cloud cover and precipitation. For instance, during the Last Glacial Maximum of 18,000 years ago, thermal-driven evaporation from the oceans onto continental landmasses was low, causing large areas of extreme desert, including polar deserts (cold but with low rates of cloud cover and precipitation). In contrast, the world's climate was cloudier and wetter than today near the start of the warm Atlantic Period of 8000 years ago.
Estimated global land precipitation increased by approximately 2% over the course of the 20th century, though the calculated trend varies if different time endpoints are chosen, complicated by ENSO and other oscillations, including greater global land cloud cover precipitation in the 1950s and 1970s than the later 1980s and 1990s despite the positive trend over the century overall. Similar slight overall increase in global river runoff and in average soil moisture has been perceived.
Dendroclimatology
Dendroclimatology is the analysis of tree ring growth patterns to determine past climate variations. Wide and thick rings indicate a fertile, well-watered growing period, whilst thin, narrow rings indicate a time of lower rainfall and less-than-ideal growing conditions.Ice cores
Analysis of ice in a core drilled from an ice sheet such as the Antarctic ice sheet, can be used to show a link between temperature and global sea level variations. The air trapped in bubbles in the ice can also reveal the CO2 variations of the atmosphere from the distant past, well before modern environmental influences. The study of these ice cores has been a significant indicator of the changes in CO2 over many millennia, and continues to provide valuable information about the differences between ancient and modern atmospheric conditions.Animals
Remains of beetles are common in freshwater and land sediments. Different species of beetles tend to be found under different climatic conditions. Given the extensive lineage of beetles whose genetic makeup has not altered significantly over the millennia, knowledge of the present climatic range of the different species, and the age of the sediments in which remains are found, past climatic conditions may be inferred.Similarly, the historical abundance of various fish species has been found to have a substantial relationship with observed climatic conditions. Changes in the primary productivity of autotrophs in the oceans can affect marine food webs.
Sea level change
Main articles: Sea level and Current sea level rise
Global sea level change for much of the last century has generally been estimated using tide gauge measurements collated over long periods of time to give a long-term average. More recently, altimeter measurements — in combination with accurately determined satellite orbits — have provided an improved measurement of global sea level change. To measure sea levels prior to instrumental measurements, scientists have dated coral reefs that grow near the surface of the ocean, coastal sediments, marine terraces, ooids in limestones, and nearshore archaeological remains. The predominant dating methods used are uranium series and radiocarbon, with cosmogenic radionuclides being sometimes used to date terraces that have experienced relative sea level fall. In the early Pliocene, global temperatures were 1–2˚C warmer than the present temperature, yet sea level was 15–25 meters higher than today.For more visit Wikipedia
DO YOU KNOW?
- If you sit for more than 11 hours a day, there's a 50% chance you'll die within the next 3 years
- There are at least 6 people in the world who look exactly like you. There's a 9% chance that you'll meet one of them in your lifetime..
- Sleeping without a pillow reduces back pain and keeps your spine stronger..
- A person’s height is determined by their father, and their weight is determined by their mother..
- If a part of your body "falls asleep", you can almost always "wake it up" by shaking your head..
- There are three things the human brain cannot resist noticing - Food, attractive people and danger.
- Right-handed people tend to chew food on their right side..
- Putting dry tea bags in gym bags or smelly shoes will absorb the unpleasant odour.
- According to Albert Einstein, if honey bees were to disappear from earth, humans would be dead within 4 years..
- There are so many kind of apples, that if you ate a new one everyday, it would take over 20 years to try them all.
- You can survive without eating for weeks, but you will only live 11 days without sleeping..
- People who laugh a lot are healthier than those who don’t..
- Laziness and inactivity kills just as many people as smoking..
- A human brain has a capacity to store 5 times as much information as Wikipedia..
- Our brain uses same amount power as 10- watt light bulb!!.
- Our body gives enough heat in 30 mins to boil 1.5 liters of water!!.
- The Ovum egg is the largest cell and the sperm is the smallest cell !!.
- Stomach acid (conc. HCl) is strong enough to dissolve razor blades!!.
- SMILE. It is the ultimate antidepressant.
Thursday 28 January 2016
Sunday 24 January 2016
Job vs Career (final part)
Advice About Careers
In a career, however, your goal is to not only get the task
done, but it’s also to learn skills, gain experiences, build connections, and
put yourself in position for promotions, raises, and possibly similar positions
in other organizations. That’s a lot more than just getting the task done, and
that means putting your ear to the grindstone.
In other words, you should be investing at least some emotional
energy into a career. You should be looking for ways that you can get
promotions and raises and bonuses and useful resume-building skills and
experience. This means always going the extra mile and doing tasks that are
beyond your minimum job description, building positive relationships with
people around you, and so on.
You should fight hard for a career until you get to the level
of success that you want. That doesn’t mean alienating other pieces of your
life. It means setting a professional goal, figuring out what you have to do to
get there, and getting to work.
A Comparative Example: Convenience Store Clerk
Most people treat convenience store clerking as a job. They
go in, do the minimal tasks that are assigned to them by the manager, and watch
the clock until they can get out of there to do something else. You know what?
That’s what they should be doing. It’s merely a job to them – a way to trade
some time for some cash. They don’t want to work at this all their life – they
just want a few bucks in their pocket.
Some people treat it as more than a job, though. They hope
to become a manager at the store and, perhaps someday, own a store. They take
the work seriously, and when there’s no clerking tasks to go around, they spend
their time doing other things that need to be done: cleaning the store,
learning how the accounting procedures work, and other things like that.
They ask lots of questions of the manager and use that for
fuel to learn what’s going on, and they often remain as a clerk for many years.
Quite often, these people get promoted to assistant manager and sometimes do
become the manager
The Big Point
Know going in whether or not this employment opportunity is
a job or a career. Ask yourself whether
you hope to be promoted at some point, or you just need to collect a paycheck.
If you just need a paycheck, simply don’t become emotionally
involved at all. Do the tasks you’re told to do and conserve your emotional and
mental energy for the other pieces of your life. If you’re hoping that this
employment opportunity will push you on to other things, then turn on the
passion.
Figuring this out right off the bat can save you a ton of investment
in a job. Save that investment for your family, your passions, or your career.
What’s the Difference Between a Job and Career?
So as you can see, while one can work very hard at a job and
even be paid well to work a job, a career takes much more motivation and forward-thinking
effort than a job. Due to this people usually care more about a career than
they do about a job. They see personal goals as a part of their career and it
is often more a part of who they are when they are not working than a typical
job. Careers are often vocations, such as teaching. We want the people who are teaching
our children to think of it as a career, not just a job. We want them to have
an interest in our children and care about the success of our children, rather
than just coming in, practicing a required skill, and leaving for the day
without feeling the desire to become a better teacher every day.
Do You Want a Job or a Career?
Whether a job or career is the right fit for you will depend
on your stage of life. Jobs can help people start careers in many ways –
experience, knowledge, learning about what they like and dislike. Eventually
though, striving for a career is a very positive step because it means you want
more out of the work you do than a paycheck. You want to develop your talents, really
enjoy what you do, and care about how you spend your time each day. In
addition, your earning potential is much higher in a career than in a job in
most cases.
A career takes goal setting and education (through college,
work experience, or self-learning). It is best to follow your interests,
skills, and talents to find the career that will bring you success. Success
includes money, but is also very much about personal happiness.
JOB vs CAREER part 2
Definition of Job and Career
“Job” is defined as a piece of work, esp. a specific task
done as part of the routine of one's occupation or for an agreed price. a post
of employment; full-time or part-time position. anything a person is expected
or obliged to do; duty; responsibility. It usually is considered to pertain to
remunerative work (and sometimes also formal education).
A job is defined as anything a person is expected or obliged
to do; a piece of work, especially a specific activity done as part of the
routine of one's occupation or for an agreed price.
Through a job a person can earn to support her basic needs
and family or friends. A job can also be viewed as a contract between the
employer and the employee. In commercial enterprises, the basic purpose of a
job is to create profits for the employer, and the employee contributes labor
to the enterprise, in return for payment of wages, or stock options etc.
"Career" is defined as an occupation or
profession, esp. one requiring special training, followed as one's lifework. a
person's progress or general course of action through life or through a phase
of life, as in some profession or undertaking
At a typical job, your goal is usually just to get the task
done and not annoy the boss. All you really want from a job is a regular
paycheck and a positive reference from the boss, and all you have to do to get
that done is to get your tasks done and stay out of the way.
This means that you shouldn’t be investing significant
emotional energy into the job. Just do what you’re supposed to do with the
minimum amount of expended mental and physical and emotional energy, and save
that energy for other endeavors.
If your employment situation sounds more like a job
than a career, you shouldn’t be killing yourself for it. You should be doing
the tasks that are required, then conserving your energy for the other things
going on in your life – a second job, raising a family, trying to jump-start a
career, and so on Friday 22 January 2016
JOB vs CAREER part 1
A job is simply something you do to earn money. Career
advancement is not something you're interested in there and the work
often doesn't interest you at all. In five years, you'll likely not be
doing anything like your current job.
A person usually holds several jobs in their career. It is usually easier to change jobs in the same field of work that define ones career. However, switching careers is more difficult and may require the person to start at the bottom of the ladder in the new career.
A person usually holds several jobs in their career. It is usually easier to change jobs in the same field of work that define ones career. However, switching careers is more difficult and may require the person to start at the bottom of the ladder in the new career.
CAREER
|
JOB
|
|
What is it?
|
A career is the pursuit of a lifelong ambition or the
general course of progression towards lifelong goals.
|
Job is an activity through which and individual can earn money.
It is a regular activity in exchange of payment.
|
Requirements
|
Usually requires special learning that includes individualized
components that develop abilities beyond that which training is capable of.
|
Education or Special training may or may not be required
|
Risk taking
|
A career may not mean stability of work as it encourages
one to take risks. The risks are often internal and therefore planned
|
A job is “safe”, as stability of work and income is there.
However shifting priorities, especially in resource jobs, can abruptly change
the demand and require relocation which is an unstable factor. Risks may be completely
external.
|
Time
|
Long term
|
Short term
|
Income
|
Benefits may be higher. Salary is more common
|
Varies by demand. More likely to be wage.
|
Contribution to society
|
Varies depending on value to society or to some other
entity. Non-monetary. May have high value as social change/progress may be
possible
|
May actually have a negative impact when counterproductive
social practices are continued in the name of protecting jobs.
|
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