Global Warming

Is Global Warming real?

YES, and the effects will be very bad for mankind.

The climate of the Earth is slowly warming. Measuring changes in climate, which are small and gradual, is difficult because of the weather fluctuations that are much larger. However, the warming is apparent in weather records that span many decades. Other evidence is the melting of glaciers, the break up of ice shelves on the Antarctic peninsula, and the decline of north polar sea ice cover.

As the Earth warms, the water in the oceans will expand, and the ice sheets in Greenland and Antarctica will melt and flow into the oceans. The melting of the Greenland and Antarctic ice caps will cause a rise in sea level of more than 60 meters (200 feet,) displacing hundreds of millions of people who live in coastal cities and river deltas. It is difficult to predict how fast all this will happen.

Melting Glaciers

Argentiere Glacier 1850 etching	Argentiere Glacier 1966 photograph
Fig. 46, Imbre and Imbre 1979

Muir Glacier 1941

Muir Glacier 1950

Muir Glacier 2004

Shrinking Area of North Polar Sea Ice

Annual minimum area of arctic sea ice showing the decline in area from 1979 through 2007.

The 2008 minimum area of arctic sea ice compared with the 1979-2000 median minimum showing how the recent minimum coverage is much less than the 1979-2000 median minimum.

Breakup of Antarctic Ice Shelves

Since the 1950s, a total of 25,000 km² of ice shelf has been lost from around the Antarctic Peninsula.

The shattered "Larsen B" Antarctic ice shelf compared to the area of the state of Rode Island.

Increasing Temperature

Is Global Warming caused by burning fossil fuels?

YES, burning fossil fuels produces carbon dioxide, a greenhouse gas, which is transparent in visible light, allowing the sun to heat the Earth, but absorbs infra-red light preventing the Earth from cooling.

The Earth in visible light on the left, and infra-red light on the right. Clouds, the surface of the ocean, and Africa can be seen in visible light. In infrared light, the surface is obscured by H₂O and CO₂ absorption, and only the cloud tops can be seen.

Fig. 49 from Imbre and Imbre, 1979
We know that the Earth was warmer in the past, the Antarctic ice sheet was not present, and the carbon dioxide levels then were also high.
We have accurate measurements that show that carbon dioxide levels in the atmosphere have been increasing over the last half century. We know that burning fossil fuels (coal, oil, and natural gas) produces carbon dioxide that is released into the atmosphere. We know that carbon dioxide is a greenhouse gas. However, it is difficult to predict how much warming a given amount carbon dioxide will produce, and how fast the warming will occur.

On the left is a graph of temperature change vs. atmospheric carbon dioxide in parts per million (ppm). It was calculated using data for the decrease in infrared transmission produced by increasing carbon dioxide, and increasing the Earth's temperature so that the flux of radiation from the Earth at the new temperature would still balance the flux absorbed from the Sun.

In the 1830s, at the start of industrialization, the carbon dioxide levels were around 280 ppm. Now they are almost 400 ppm (392 ppm in November 2011). This simple calculation shows an expected increase in temperature of 2.6 degrees as atmospheric carbon dioxide increases from 300ppm to 400ppm.
However, this calculation does not consider the effects of the increase in atmospheric water vapor that higher temperatures would produce. On the one hand, water vapor is a greenhouse gas, and would decrease the infrared transparency and increase the greenhouse heating. On the other hand, more atmospheric water vapor would produce more clouds, and reduce the heading from the sun.

Fig. 48 from Imbre and Imbre, 1979
We know that the ice ages were caused by small changes in the orbit of the Earth produced by perturbations from the other planets. These orbital changes caused less sunlight to fall at high latitudes, with the result that the winter snow could not melt completely in summer, and accumulated to form ice sheets. At present, the orbital changes should be producing cooling, but the Earth is warming because the greenhouse gas that we are producing is overwhelming the natural cooling effect.

Why are we burning fossil fuels?

Our modern lifestyle requires large amounts of cheap energy, and burning fossil fuels gives us cheap electricity, and cheap energy for transportation and industry.

How can we halt Global Warming?

We must stop burning fossil fuels. The best choice is to find alternative sources of energy for our electricity, transportation, and industry. We could also reduce our energy requirements by reducing the amount energy each person consumes, or by reducing the number of people consuming energy.

Nuclear Power is not a solution.

If we do not act now to implement alternative sources of energy, Global Warming will reduce our population and force a primitive living standard upon us.

REFERENCES
Imbre, J. and Imbre, K. P., 1979 "Ice Ages: Solving the Mystery" (Harvard University Press: Cambridge) ISBN 0-674-44075-7
Ladurie, E. L., 1971 "Times of Feast and Famine: A History of Climate since the Year 1000" Trans. by Barbara Bray (Doubleday: New York)
Broecker, W. S., 1971 "Science," 189, pp.460-463
Mitchell, J. M. Jr., 1977 "Environmental Data Service, March, U. S. Dept. Comm.," pp.3-9

contact: Bruce A. Peterson
158th access Last modified: Sun 15 Jan 2012

Fig. 49 from Imbre and Imbre, 1979	We know that the Earth was warmer in the past, the Antarctic ice sheet was not present, and the carbon dioxide levels then were also high. We have accurate measurements that show that carbon dioxide levels in the atmosphere have been increasing over the last half century. We know that burning fossil fuels (coal, oil, and natural gas) produces carbon dioxide that is released into the atmosphere. We know that carbon dioxide is a greenhouse gas. However, it is difficult to predict how much warming a given amount carbon dioxide will produce, and how fast the warming will occur.
	On the left is a graph of temperature change vs. atmospheric carbon dioxide in parts per million (ppm). It was calculated using data for the decrease in infrared transmission produced by increasing carbon dioxide, and increasing the Earth's temperature so that the flux of radiation from the Earth at the new temperature would still balance the flux absorbed from the Sun.
In the 1830s, at the start of industrialization, the carbon dioxide levels were around 280 ppm. Now they are almost 400 ppm (392 ppm in November 2011). This simple calculation shows an expected increase in temperature of 2.6 degrees as atmospheric carbon dioxide increases from 300ppm to 400ppm. However, this calculation does not consider the effects of the increase in atmospheric water vapor that higher temperatures would produce. On the one hand, water vapor is a greenhouse gas, and would decrease the infrared transparency and increase the greenhouse heating. On the other hand, more atmospheric water vapor would produce more clouds, and reduce the heading from the sun.
Fig. 48 from Imbre and Imbre, 1979	We know that the ice ages were caused by small changes in the orbit of the Earth produced by perturbations from the other planets. These orbital changes caused less sunlight to fall at high latitudes, with the result that the winter snow could not melt completely in summer, and accumulated to form ice sheets. At present, the orbital changes should be producing cooling, but the Earth is warming because the greenhouse gas that we are producing is overwhelming the natural cooling effect.