Why is there ice on earth?
Answer:
The entire notion of a global average temperature is poppycock. Here is good link that explains the observed temperatures over Greenland in the last 100 years or so, which suggest they can't be linked with human activity.
http://www.co2science.org/scripts/co2sci...
Here's an snippet:
"In commenting on this dramatic temperature rise, which they call the great Greenland warming of the 1920s, Chylek et al. conclude that "since there was no significant increase in the atmospheric greenhouse gas concentration during that time, the Greenland warming of the 1920s demonstrates that a large and rapid temperature increase can occur over Greenland, and perhaps in other regions of the Arctic, due to internal climate variability such as the NAM/NAO [Northern Annular Mode/North Atlantic Oscillation], without a significant anthropogenic influence."
You are correct. One of the arguments for global warming states that the ozone layer has been depleted at the poles, raising the mean temperature of the poles. This is leading to more ice melting. So even if the rest of the world stays the same or even goes down a bit, the particularly large change at the poles will result in the ice melting. Good question and argument!
YES BUT... IT IS A GEOMETRY PROBLEM... AND SO FAR THE GEOMETRY OF OUR EARTH (GLOBE) IS CONSTANT
The temperature balance is set mostly be the solar radiation through the quantity of sun which is radiated back to space or reflected and absorbed.
The composition of the atmosphere is not very different around the earth.
The largest difference between the equator and the poles is the solar radiation. This is a geometry problem...
You can try it by illuminating from far a small ball with a flashlight. The angle between the direction and the poles makes that the same section of sun light (e.G. 1m²) irradiates 1m² on the equator but tens of m² on the poles. Therefore the energy radiating per m² is less.
Also the poles are for the moment white which has a large reflection of the light. In turn, not a lot of energy is absorbed; a lot is reflected to space.
You are confusing temperature with energy, and the entire system is not homogenized.
It takes a certain amount of energy to melt ice to water without changing the temperature. It is called the Latent Energy of Fusion. Without changing temperature, just by changing state, water absorbs and releases energy.
You also have said nothing about the flux density of solar radiation at the equator versus the poles ... don't you think that makes a difference?
This is why the environment is called a "complex system".
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What you say is quite correct if the composition of the atmosphere were not being changed by our overuse of hydrocarbon based fuels. If the earth were not tilted and the distribution of heat were not in constant flux then the equator would get warmer and warmer while the poles would become colder and colder. I am afraid that the problem of global warming is far more complex than any one reason but a compilation of many factors some of which are out of our control and some of which are in our control
http://en.wikipedia.org/wiki/global_warm...
Because of the Ice Age and how the Earth is 75% water. But beacuse of Global Warming, most of the World's beautiful Icebergs and Mountain snow is gone because of global warming.
The mean temperature increase means that whatever the temperature at the arctic was has increased and whatever the temperature at the equator was has increased. Our seasons maintain the amount of ice we have but if the ice melts and the mean temperature increases then it will not refreeze the same amount from the previous season. An increase in mean temperatue increases the amount of time the water is at a temperature above freezing and decreases the amount of time it has below or at freezing.
Temperature distribution would only change if the earth's axis changed because the equator is simply the part of the earth that always gets relatively close rays from the sun no matter the season. Things you can study up on to get a better idea is the axis and tilt of the earth about its revolutional shape around the sun, greenhouse gases, cloud cover, ocean temperatures and currents, and finally air densities and solar activity. That should open your mind up a bit about Global Warming.
Global warming is the increase in the average temperature of the Earth's near-surface air and oceans in recent decades, and its projected continuation.
Global average air temperature near the Earth's surface rose 0.74 ± 0.18 °C (1.3 ± 0.32 °F) during the past century. The Intergovernmental Panel on Climate Change (IPCC) concludes, "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations," which leads to warming of the surface and lower atmosphere by increasing the greenhouse effect. Natural phenomena such as solar variation combined with volcanoes have probably had a small warming effect from pre-industrial times to 1950, but a small cooling effect since 1950. These basic conclusions have been endorsed by at least 30 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. The American Association of Petroleum Geologists is the only scientific society that rejects these conclusions, and a few individual scientists also disagree with parts of them.
Climate models referenced by the IPCC project that global surface temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100. The range of values reflects the use of differing scenarios of future greenhouse gas emissions and results of models with differences in climate sensitivity. Although most studies focus on the period up to 2100, warming and sea level rise are expected to continue for more than a millennium even if greenhouse gas levels are stabilized. This reflects the large heat capacity of the oceans.
An increase in global temperatures can in turn cause other changes, including sea level rise, and changes in the amount and pattern of precipitation. There may also be changes in the frequency and intensity of extreme weather events, though it is difficult to connect specific events to global warming. Other effects may include changes in agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors.
Remaining scientific uncertainties include the exact degree of climate change expected in the future, and how changes will vary from region to region around the globe. There is ongoing political and public debate regarding what, if any, action should be taken to reduce or reverse future warming or to adapt to its expected consequences. Most national governments have signed and ratified the Kyoto Protocol aimed at combating greenhouse gas emissions.!!!mas
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