What is global warming in general?

Question

When do we say its a global warming?When will it become dangerous?Does it really has disadvantages to humans?How can we prove that a certain calamity or disaster be it known as global warming?

Answer 1

Short answer first, more details later.

SHORT ANSWER
1) The term Global Warming (GW) is usually used to refer to the unprecendented rise in temps we've witnessed in the last 200 years and particularly in respect of the role humans have had in this warming.

2) It already is dangerous. The World Health Organisation (WHO) has calculated that GW is killing one person every 3 minutes, a figure that is set to double. The WHO also predicts a large increase in cases of diseases such as malaria and others that have a direct link to temperature and climatic conditions.

3) There are many disadvantages to humans and some advantages too. Higher temperatures mean less cold releated illnesses and deaths, melting permafrost means more agricultural land, there will be less need for heating and so a saving on energy bills. The disadvantages are explained more in the long answer.

4) Sometimes it's hard toprove a particular calamity is the result of global warming, instead of doing this we look at averages. For example, Hurricane Katrina may or may not have been influenced by global warming. If there was no warming it may or may not have happened, it may have happened elsewhere, it may have been worse. What we do know is that hurricanes, tornadoes, cyclones etc are greatly influenced by climatic conditions and that global warming is producing more conducive conditions, as a result there has been a significant increase in the number and intensity of storms.


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LONG ANSWER - CURRENT EFFECTS


EFFECTS ON WEATHER
An increase in the amount of precipitation. Although rainfall overall will increase there are some parts of the world that are already receiving less rainfall and this trend is likely to continue.

Hurricanes and storms will become more frequent, widespread and severe, in the last 30 years the proportion of category 4 and 5 hurricanes has almost doubled. Once exclusively confined to the northern hemisphere there have recently been hurricanes in the southern hemisphere, most notably in Brazil.

DESERTIFICATION
Shifting weather patterns mean some areas receive less rainfall; the ground becomes barren and unable to sustain crops. In many parts of the world the layer of topsoil is both very thin and very poor. The dry, dusty soil is readily blown away and the area becomes desert. African and Asian countries are particularly hard hit.

AGRICULTURAL IMPACT
For the reasons mentioned above there will be a major impact on agriculture. Rising sea levels will result in the loss of large areas of agricultural land, the consequences of which will be population migration, famine and / or the need to import food from elsewhere. Again, it will be the African and Asian countries that are hardest hit with crop production falling by up to a third.

RISING SEA LEVELS
Sea levels are rising faster now than at any time since the melting of the glaciers that marked the end of the last ice age. As the glaciers melted sea levels rose by some 120 metres (400 feet) but for the last few thousand years sea levels have been almost constant rising only 10 centimetres (4 inches) per thousand years.

Since the onset of global warming the seas have risen much faster. A hundred years ago they were rising by 1mm a year, today they are rising by 3mm a year and indications are that they will rise much quicker in the future. Sea levels are rising 30 times faster now than they were before industrialisation and the onset of global warming.

The Sundarman Delta has seen levels rising by more than 30mm a year, millions have already been forced to leave their homes and the Carteret Islands in the Pacific Ocean are currently being evacuated.

In years to come rising sea levels could swamp cities including London, New York and Miami. Low lying areas such as Bangladesh, much of the European and American coasts and island groups including the Seychelles and Maldives would be submerged.

MELTING OF ICE CAPS
The Arctic ice cap is floating; if it were to melt entirely there would be no change in sea levels. However, Antarctica is a continent, a land mass, it isn’t floating and any melting here adds to the sea level as does melting of ice sheets and glaciers in places such as Greenland.

The edges of the Antarctic Ice Sheet are breaking off and collapsing into the sea. One of the biggest breaks occurred in 2002 when the Larsen B Ice Shelf broke off. This huge mass of ice covered 3250 square kilometres and weighed half a trillion tons.

POPULATION MIGRATION
For the reasons mentioned above, large numbers of people are going to find it increasingly difficult to remain in their present locations and in many cases it will be impossible. In Bangladesh some 13 million people will be forced to move if the sea level rises by just one metre and in the US tens of millions will be affected particularly along the north east coast, Florida, Louisiana and California. Globally it is expected that hundreds of millions of people will need to relocate or emigrate.

MARINE ENVIRONMENT
The world’s oceans absorb carbon dioxide, some of which dissolves to form carbonic acid and this is affecting the alkalinity of the oceans. Many forms of marine life are highly sensitive to the level of alkalinity. The formation of corals is being affected and plankton, which forms the basis of the marine food chain, is also very sensitive. The increasing levels of carbon dioxide make it harder for many species of fish and shellfish to breathe and reproduce. Changes in the ecology and chemistry of the seas and oceans reduce their ability to absorb CO2, which consequently increases the rate of global warming.

ECOSYSTEMS
Parts of Antarctica are now covered in grass and there is a massive migration of animals towards the polar regions, these migrations extend an average of 6.1km further from the equator each decade. Butterflies have extended their territory by some 200km further north in Europe and North America.

In the Arctic the habitat of polar bears and emperor penguins is being threatened. The waters of the Hudson Bay for example, are now ice free for three weeks more each year than they were 30 years ago. Polar bears are starving because they need to venture onto the frozen ice to hunt food. In another 10 or 20 years there may no longer be polar bears in this region and within a hundred years they could be extinct.

The most extensive report into global warming and climate change predicts that up to 40% of animal species could become extinct due to global warming.

HEALTH AND DISEASE
Global warming will be both beneficial and detrimental to people's health. There will be fewer deaths from cold related conditions but more deaths from heat related conditions. Globally there are more heat related deaths than cold related deaths so the net impact will be a loss of life.

Warmer temperatures lead to an increase in air and water pollution thus increasing the risk to humans from infection and respiratory conditions such as asthma. Warmer temperatures are conducive to the breeding and spread of rats, mice, other rodents, ticks, mosquitoes and other vectors for disease. This will lead to an increase in the number of people affected and an expansion into previously unaffected areas.

WATER SCARCITY
Rising sea levels lead to the contamination of groundwater rendering it undrinkable whilst at the same time higher temperatures lead to greater evaporation of fresh water from reservoirs. This will impact on the human population as well as plants, animals and agriculture.

Higher temperatures and changing climate patterns mean that some areas will receive less rainfall, in other areas when the rain does fall it is likely to do so on hard, sun-baked ground which is unable to absorb it. Instead of replenishing groundwater supplies the water will run off causing flash flooding and a lowering of the water table.

MOUNTAIN ENVIRONMENTS
Glaciers are melting faster than has been known before - up to 40 metres per day in some places. In the last 100 years 50% of the world’s glaciers outside the polar regions have melted. The effects of glacial melt include flooding, landslides, avalanches and loss of habitat. In some mountainous regions melt water provides a year round water supply and without the glaciers there will be near drought conditions.

ECONOMY
Increased adverse weather in itself could cost 1% of the worldwide GDP and a temperature rise of 2 or 3°C would reduce global economic output by 3%. In percentage terms these aren’t very big numbers but in terms of dollars the cost runs into trillions.

Insurance premiums are rising in line with the increased number of claims. The Association of British Insurers notes a 100% rise in weather related claims in recent years and states that climate change is already seriously impacting on the insurance industry.

THERMOHALINE CIRCULATION
A possible effect of global warming is the failure or slowing of the ocean conveyor belts or meridional overturning circulation. Research is continuing and it's unclear at this time what effect, if any, global warming will have on thermohaline circulation. One theory is that the melting of polar ice could reduce salinity and introduce cold water into the oceans which could trigger a slowing or shutdown of thermohaline circulation. It's thought that the Gulf Stream which conveys warm Caribbean water to the coasts of Ireland, Britain and northern Europe is the most likely to be affected. Should this occur temperatures in these regions would drop be several degrees.

CIVIL ENGINEERING
A rise in sea levels would need to be countered with extensive flood defence schemes. Costly engineering schemes would need to be constructed in order to protect coastal cities. Many countries would not be able to afford such schemes and low lying communities may need to be evacuated.

Temperature fluctuations cause damage to road surfaces, pipelines including oil, gas, water and sewerage pipes, railway lines and airport runways. Greater contraction and expansion resulting from fluctuating temperatures and greater temperature ranges weakens the structure.

DEVELOPING NATIONS
The developing nations are expected to be the worst affected by global warming. Decreasing rainfall, drought, insect infestation and severe weather events will seriously impact on crop production leading to famine and starvation. Economic development is likely to be restricted whilst at the same time poverty increases. The poorer countries of the world are the ones that have the least resources to mitigate the effects of global warming.

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LONG ANSWER - FUTURE EFFECTS


RISING TEMPERATURES
The most extensive report into climate change and global warming was conducted by the IPCC and concluded that temperature rises of between 1.8°C and 4.0° should be expected by the end of the 21st century.

HEALTH IMPLICATIONS
In 2007 one person is dying every three minutes as a result of global warming, this figure is expected to double by 2020. The World Health Organisation predicts that rising temperatures will result in an additional 300,000 deaths and 10 million illnesses a year by 2030. This is in addition to the tens of millions of additional cases of malaria that the WHO expects to see.

ECOLOGICAL IMPACT
A quarter of the species of animals and plants could be extinct by 2050. More than three million square kilometres of Arctic sea ice has melted threatening the habitat of polar bears, experts predict that their numbers will ‘plummet’; the survival of grizzly bears is also threatened. Other species that are threatened include penguin, turtle, caribou, walrus, plankton, krill, whale, crab and seal.

ADVERSE WEATHER
In recent years there has been an 80% increase in the number of category 4 and 5 hurricanes. Along with cyclones, tornados and other storms the frequency looks set to keep increasing. The UK Met Office predicts a nine-fold increase in the extent of flooding within the next 50 years.

In 2003 a heatwave in Europe, one of many in recent years, claimed up to 50,000 lives, predictions are that the annual number of heat related deaths will increase significantly.

DROUGHT AND FAMINE
The heat is likely to greatly increase the number of forest fires, reduce timber production, impact on agricultural land and lead to more insect infestation which in turn impacts on crop production and human health.

Rising temperatures have a huge impact on food production, a 1°C rise equates to a 10% loss in grain production, areas already facing food shortages will be hardest hit. Warmer temperatures create severe drought conditions; billions of people will be affected by contaminated water, a lack of water or both, in China and south east Asia alone hundreds of millions will be affected.

RISING SEA LEVELS
Rising sea levels have already impacted hard on many island and coastal communities including the forced evacuation of their populations. Areas affected include Kenya, Kiribati, Marshall Islands, Tuvalu, Bangladesh, Papua New Guinea, Micronesia, Maldives, Antigua and Bermuda. Sea levels have been rising for some time and predictions indicate further rises of between 200 and 600mm by the end of the century. In the US this would affect many coastal regions especially the coastlines of Florida and the Gulf of Mexico, cities affected would include Boston, New York, Charleston, Miami and New Orleans.

OTHER EFFECTS
Some of the other impacts of global warming include: arctic warming, increased power outages, marine food chain disruption, changes to bird migration patterns, more wildfires, erosion, desertification, disappearing beaches, damage to tundra regions, impact on ozone layer, insect infestation, threat to boreal forests, coastal erosion, threat to mountain environments, loss of wetland and marshland habitats, decline in bird population, thawing of permafrost, increased acidity of oceans, release of further greenhouse gases, increased allergens (asthma etc), coral destruction and bleaching, loss of ocean conveyor belts (Gulf Stream) etc, loss of Arctic sea ice, impact on winter sports.

Answer 2

The theory holds that enough people scream about it, then it must be true. Facts and counter facts do not matter in the argument, people are screaming about global warming.

It is a theory that the planet is getting warming. There was a theory, in much the same proportion, in the 1970's about global cooling. It didn't happen then also. Some of the same global cooling scientists are the very ones talking about global warming. A person should look into funding of science and see who is actually funding what.

There is no proof for global warming other than the climate changes. It has changed in the past and it will change in the future.The planet came out of the last ice age on it's own. One would wonder how is this possible if global warming wasn't happening after a global cooling event. Mankind was not part of the equation then, so what does mankind do to impact the environment now.

Mankind puts out carbon dioxide in vast quantities and this is a "blanket" of gas in our atmosphere. Problem here is there have been larger amounts of this very gas in the atmosphere in the past. This was long before the industrial revolution and mankind had no impact on this.

All this really proves is the climate changes. It 's not static. But then you have all these people screaming "global warming". I know some companies selling "going green" products and making a fortune. There is money in scaring people about climate changes as was proven in the 1970's.

Answer 3

The earth's temperature has never been constant--it has always been on a warming or a cooling trend (ever heard of the Ice Age)? It has been on a gradual warming trend for several hundred years. Many scientists think that its warming is being accelerated by emissions from burning fossil fuels.

Will it be dangerous in our lifetime? Probably not. Some scientists say the oceans will rise (due to the melting of the polar ice caps,) leading to flooding and more hurricanes; others say ice melting won't cause the water levels to rise any more than ice melting in your glass makes it overflow. Will it affect future generations? Who knows?

Personally, I doubt all of this. The fact is: billions of dollars have been spent studying global warming, mostly by the federal government. Scientists are just people like the rest of us, with mortgages and car payments.

Answer 4

The severity of the threat has been blown way out of proportion. I encourage you to watch the Glenn Beck special tonight on CNN Headline News at 6:00 and 8:00 and 11:00 PM Central Time Zone. He presents the counterpoints to Global Warming. It promises perspectives you just don't hear in the media these days.

Answer 5

The main civilized world is about one half a billion people that drive cars and use fossil fuels. What we do here is of no effect if China at 1 billion is starting and 10 years look out. Then not quite as fast is Indian another billion . The only chance we have is to cultivate and water all green things which cleans the air.

Answer 6

read a LOT of history books. Especially on the subject of climatology and such. You'll soon find out down through history.. others got sucked into the same hysteria over the ages....let me put it more succinctly..you've been successfully 'sucked' into a global "political" phenom, not a scientific one! You wanna stop it, put more energy into exposing the myths,and junk science it's based on--that's how to stop it!

Answer 7

global warming is a lie and an "untruthful convenience"

join the heresy

http://video.google.com/videoplay?docid=4499562022478442170&hl=en

Answer 8

The earth will get warmer, causeing oceans to rise, more, powerful storms, floods, droughts.

Answer 9

http://en.wikipedia.org/wiki/Global_warming is the best answer i can give u