Since this blog doesn't have a huge following, this is a bookmark for me. I keep my eye on the arctic and antarctic. The heat balance of Earth follows the difference between incoming energy---sunlight---and outgoing energy---radiation. Greenhouse gases---Carbon Dioxide, Methane, and even water vapor, among others---block energy from leaving the planet. The more greenhouse gases, the less energy (ultimately, head) leaves the planet. Since energy loss is less than energy income, the result is accumulation of heat.
The specific heat of a substance is a measure of the amount of heat required to warm up 1 gram of the material by 1 degree Centigrade. The specific heat of liquid water is 1 calorie per gram per degree C. As the heat entering the Oceans increases, the temperature elevates, in obedience to this formula.
The specific heat does not reflect the amount of heat required to change the phase of, for example, water. To evaporate one gram of water requires 540 calories of heat, with no change in temperature; this is called the heat of vaporization. So it takes 540 times the amount of heat required to raise the temperature of a gram of water by 1 degree C, Don't forget, no temperature change occurs during this change from water to steam.
To melt a 1 gram ice cube requires 80 Calories. Again, there is no change in temperature; the water just changes from a solid to a liquid phase. This amount, 80 Calories, is called the heat of fusion. (Removal of the same amount of heat would result in changing our gram of water to a gram of ice, again with no change of temperature.
Water has an extremely high Specific Heat. It is partly for this reason that Earth is particularly suited for life. On other planets, where the average temperatures are either much higher or much lower, liquid water is not so readily available for life, for cells, for fish to swim in...
Our home planet fortunately dwells in the "Goldilocks Zone." It is not too hot; not too cold; but just right. Our ranges of temperatures, across the geography of Earth, allow the heat of fusion (melting) and vaporization (condensation) to regulate the temperatures within a limited range of temperatures that is just right.
Existence of polar ice provides a buffer when the incoming energy exceeds the outgoing heat. In times when outgoing heat exceeds the incoming energy, the poles grow; our planet has experienced times of extreme cold, when ice covered a significant portion of Earth's surface.
Fortunately, Greenhouse Gases form a barrier that regulates, in a way, the heat loss to space. Earth's levels of Carbon Dioxide may have been around 4,000 ppm. More recently, those levels have stabilized; but this graph from Earth.org, a version of the "hockey stick: graph, shows those levels increasing dramatically.
What has changed? We can start with the Industrial Revolution, and more recently the massive scale of burning of fossil petroleum to fuel planes, trains, and automobiles, as well as to generate our electricity. Carbon Dioxide was drawn from the atmosphere to build living systems; as living things died, they left fossils, some of them in liquid form as hydrocarbons---petroleum---that we now have been drawing to burn in service of our industrial economy. That old Carbon, in the form of degraded biological molecules, is being returned to an inorganic, prehistoric form through our agency. The huge increase of CO2 is Anthropogenic---generated by humans.
Fortunately for us, so far, the worse effects of the build-up of CO2 have been mitigated by the existence of ice at the North and South poles. Melting of this ice absorbs a huge amount of heat; this happens without temperature change. It is our salvation.
Sure, earth's atmosphere and oceans are warming, but once this ice is drastically reduced, the capacity for mitigation of effects of huge heat influx will be dramatically reduced.
This is why we watch the ice. Irresponsible actions born of ignorance have now resulted in the loss of one of the monitors of the arctic. Link below.
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