what is global warming?

Question

sorry i dont know
please explain ..

Answer 1

In a nutshell, I'd tell you to go to wikipedia and search for it. But in a sentence - its when the ozone layer of the planet is getting holes and the temperature of the planet is going up. This in effect melts the ice at both south and north poles which raises the sea water level and distrupts the temperature of the water as well. Therefore the weather is also affected.

Answer 2

Global warming is the human-caused phenomenon of increasing greenhouse gases leading to increasing temperatures.

CO2 is 30% higher than it has been for 650,000 years. Methane is 130% greater. These are two of the main pollutants humans put into the atmosphere in excess, and they are two of the primary greenhouse gases.

Look at the 'hockeystick', which shows a dramatic warming since 1950 after a fairly stable climate for 1000 years. In fact, the 10 hottest years in recorded history have all happened since 1990, with 2005 being the hottest, and 2006 is shaping up to maybe break that record.
(see links below)

How's that for proof of man's fault in this? There is ample proof, any real scientist will tell you that.

There has NEVER been an article doubting man's influence on global warming published in a peer-reviewed journal. A recent study of almost 1000 proved that.

Yes, the earth naturally heats and cools, but the rate and amount we are warming now is unprecedented in the recent geologic past. We are doing this, and we must stop it. This is not some political statement or rhetoric. This is science trying to educate a crass, ignorant public of the damage they are doing. The magnitude of temperature increase ALREADY is about 10x that of the 'little ice age' of the middle ages, and rate and amount are only going up.

Just to be clear, glacial and interglacial cycles are mainly controlled by astronomical fluctuations, but we have a detailed record of the last 7 cycles, and what the climate and CO2 is doing now is way different and extreme. The rate of increase is much higher than in the past AND the value itself is much higher.

HI CO2:
http://news.bbc.co.uk/1/hi/sci/tech/4467...
HOCKEY STICK:
http://news.bbc.co.uk/1/hi/sci/tech/5109...
General climate stuff:
http://news.bbc.co.uk/1/hi/sci/tech/3897...

Answer 3

It's summer.

The earth's temperature flucuates seasonally as the earth orbits our sun. Solar orbital cycles and Solar activity effect surface temperatures.. Junk science (ala, Al Gore) attempt to pawn blame off on human activity. There are inherent flaws with their theories and don't hold in the hard light of reason based scientific study.

The orbital cycle of our planet is on a 180,000 year cycle, we have exited into an interglacial period that the exiting began about 10-20,000 years ago. The orbital cycle puts us in closer proximity to our sun, and will eventually recede back to global cooling.

We've experience hotter and drier weather off and on over the last 20,000 years.

Answer 4

Global warming refers to an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities.

Answer 5

Due to excess cut down of trees, the earth get heated. This is called as Global warming.

Answer 6

The opposite of global cooling fool

Answer 7

A farce

Answer 8

fiction

Answer 9

Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades.However, observed or not, global warming just feels untrue.

The Earth's average near-surface atmospheric temperature rose 0.6 ± 0.2 °Celsius (1.1 ± 0.4 °Fahrenheit) in the 20th century. The prevailing scientific opinion on climate change is that "most of the warming observed over the last 50 years is attributable to human activities" [1].

The increased amounts of carbon dioxide (CO2) and other greenhouse gases (GHGs) are the primary causes of the human-induced component of warming. They are released by the burning of fossil fuels, land clearing and agriculture, etc. and lead to an increase in the greenhouse effect.

The measure of the response to increased GHGs, and other anthropogenic and natural climate forcings is climate sensitivity. It is found by observational [2] and model studies. This sensitivity is usually expressed in terms of the temperature response expected from a doubling of CO2 in the atmosphere. The current literature estimates sensitivity in the range 1.5-4.5 °C (2.7-8.1 °F). Models referenced by the Intergovernmental Panel on Climate Change (IPCC) predict that global temperatures may increase by between 1.4 and 5.8 °C (2.5 to 10.5 °F) between 1990 and 2100. The uncertainty in this range results from both the difficulty of predicting the volume of future greenhouse gas emissions and uncertainty about climate sensitivity.

An increase in global temperatures can in turn cause other changes, including a rising sea level and changes in the amount and pattern of precipitation. These changes may increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Other consequences include higher or lower agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors. Warming is expected to affect the number and magnitude of these events; however, it is difficult to connect particular events to global warming. Although most studies focus on the period up to 2100, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has a long average atmospheric lifetime. [3].

Only a small minority of climate scientists discount the role that humanity's actions have played in recent warming. However, the uncertainty is more significant regarding how much climate change should be expected in the future, and there is a hotly contested political and public debate over what, if anything, should be done to reduce or reverse future warming, and how to deal with the predicted consequences.

The term 'global warming' is a specific case of the more general term 'climate change' (which can also refer to 'global cooling', such as occurs during ice ages). In principle, 'global warming' is neutral as to the causes, but in common usage, 'global warming' generally implies a human influence. However, the UNFCCC uses 'climate change' for human-caused change, and 'climate variability' for other changes [4]. Some organizations use the term 'anthropogenic climate change' for human-induced changes.
Greenhouse gases are transparent to shortwave radiation from the sun. However, they absorb some of the longer infrared radiation emitted as black body radiation from the Earth, making it more difficult for the Earth to cool. How much they warm the world by is shown in their global warming potential.

The atmospheric concentrations of carbon dioxide and methane have increased by 31% and 149% respectively above pre-industrial levels since 1750. This is considerably higher than at any time during the last 650,000 years, the period for which reliable data has been extracted from ice cores. From less direct geological evidence it is believed that carbon dioxide values this high were last attained 40 million years ago. About three-quarters of the anthropogenic emissions of carbon dioxide to the atmosphere during the past 20 years is due to fossil fuel burning. The rest is predominantly due to land-use change, especially deforestation [6].

The longest continuous instrumental measurement of carbon dioxide mixing ratios began in 1958 at Mauna Loa. Since then, the annually averaged value has increased monotonically by approximately 21% from the initial reading of 315 ppmv, as shown by the Keeling curve, to over 380 ppmv in 2006 [7] [8]. The monthly CO2 measurements display small seasonal oscillations in an overall yearly uptrend, with the maximum reached during the northern hemisphere's late spring (the growing season in the northern hemisphere temporarily removes some CO2 from the atmosphere).

Methane, the primary constituent of natural gas, enters the atmosphere both from biological production and leaks from natural gas pipelines and other infrastructure. Some biological sources are natural, such as termites, but others have been increased or created by agricultural activities, such as the cultivation of rice paddies [9]. Recent evidence suggests that forests may also be a source (RC; BBC), and if so this would be an additional contribution to the natural greenhouse effect, and not to the anthropogenic greenhouse effect (Ealert).

Future carbon dioxide levels are expected to continue rising due to ongoing fossil fuel usage, though the actual trajectory will depend on uncertain economic, sociological, technological, and natural developments. The IPCC Special Report on Emissions Scenarios gives a wide range of future carbon dioxide scenarios [10], ranging from 541 to 970 parts per million by the year 2100.


Anthropogenic emission of greenhouse gases broken down by sector for the year 2000.Globally, the majority of anthropogenic greenhouse gas emissions arise from fuel combustion. The remainder is accounted for largely by "fugitive fuel" (fuel consumed in the production and transport of fuel), emissions from industrial processes (excluding fuel combustion), and agriculture: these contributed 5.8%, 5.2% and 3.3% respectively in 1990. Current figures are broadly comparable.[11] Around 17% of emissions are accounted for by the combustion of fuel for the generation of electricity. A small percentage of emissions come from natural and anthropogenic biological sources, with approximately 6.3% derived from agriculturally produced methane and nitrous oxide.

Positive feedback effects, such as the expected release of methane from the melting of permafrost peat bogs in Siberia (possibly up to 70,000 million tonnes), may lead to significant additional sources of greenhouse gas emissions. [12]. Note that the anthropogenic emissions of other pollutants - notably sulfate aerosols - exert a cooling effect; this partially accounts for the plateau/cooling seen in the temperature record in the middle of the twentieth century [13], though this may also be due to intervening natural cycles.