In last Sunday’s column, I mentioned some of the themes of the documentary, “Earth: An Operating Manual” by Richard Alley, a climate scientist at Penn State.

Alley has diverse experience that give him a more objective perspective on climate change. Alley has done research across the globe from the polar regions to the Antarctic as well as having been employed by an oil company.

Alley sees the need to address both the growing increase of carbon dioxide in our air (causing to climate to change) and reducing our reliance on fossil fuels. Our global civilization is consuming fossil fuels at a rate that is a million times faster than the time it took to form these fossil fuels.

The U.S. military knew about global warming in the 1940s from its development of heat-seeking missiles. These missiles had more difficulty in locating their targets as the whole atmosphere was warming up due to the absorption of heat by carbon dioxide (CO2) gas (that absorbs heat from the Earth’s surface and reemits it downward).    

From analysis of ice cores over the past 400,000 years, the global temperature rises and falls with the increase of CO2 in our atmosphere. The present CO2 concentration in our atmosphere is nearing 400 parts per million, compared to the previous highs of 280 parts per million.

A key question that climate skeptics raise is: How can we be sure that humans are mainly responsible for global warming? Perhaps there are natural variations causing warming around the world?

In regard to the increasing atmospheric concentration of CO2, consider the main natural source of CO2, volcanic eruptions. Our global civilization by its burning of fossil fuels emits 50 to 100 times as much CO2 as volcanoes.

The CO2 emitted by volcanoes comes from the melting of rocks deep below the surface, which taps oxygen from the mineral oxides there. The observed drop in atmospheric oxygen levels is consistent with fossil fuel burning (carbon combines with oxygen molecules in air).

There are three kinds of carbon atoms, Carbon–12, which plants tend to use, Carbon-13, somewhat rarer and radioactive Carbon-14, made from cosmic ray bombardment in our atmosphere. The content of the CO2 in our present atmosphere has a Carbon-12 concentration consistent with the burning of plant matter (fossil fuels).

   Is it possible that we can reduce our consumption of fossil fuels? Alley reviews the main renewable energy sources. Presently, our global civilization is consuming 15.7 terrawatts of energy 24/7. (A terrawatt is 1 trillion watts or 1 million x million watts).    

The sunlight striking the Earth’s upper atmosphere is 173,000 terrawatts 24/7, over 11,000 times the energy humanity uses. If we could harness just 0.01 percent of this sunlight, then we could get the energy we need.

But the sun shines only half the time and some days it’s cloudy. But there are ways to store this energy and transmit this energy as electricity across large distances.

The deserts of the American Southwest could generate 80 percent of world’s energy if the above problems were overcome. Some countries such as Canada, Brazil and Norway get much of their electric energy from hydroelectric facilities. If all of the world’s hydroelectric potential were realized, 12 times as much energy as we now use could be harnessed.    

Another renewable energy source is biomass, the burning of plants. By converting this to biodiesel, as much as 11 times as much energy as we now use could be gained (without any net gain in atmospheric CO2) provided fossil fuels are not involved (as in corn based ethanol).    

Geothermal energy, from hot rocks deep in the Earth, could free up three times as much energy as we use.    

Lastly, if all the power of the winds were tapped by offshore wind turbines and in land wind corridors, up to 78 times as much energy would be available.    

If these renewable sources were tapped, our energy pie in 2030 could be: solar — 26 percent, wind — 13 percent, geothermal — 13 percent, biomass — 4 percent, hydro — 5 percent, nuclear (both old and new plants) — 26% and fossil fuels only 13 percent.

So if we accept the facts, we can turn to new alternatives for our energy, and reduce somewhat the problems of energy security, global food and water supplies, the spread of diseases and mass migrations.

  The evening moon grows to full on July 14, appearing above and to the right of Sagittarius (Tea Pot). Just as for June’s full moon, this month’s full moon has a low track across the night sky. July’s full moon is visible for about ten hours, rising about sunset, cresting only 1/3 of the way up in the south and setting as the sun rises. Four nights later, the moon will have fled into the morning sky, not rising till after midnight.

Bob Doyle invites any readers comments and questions. E-mail him at rdoyle@frostburg.edu . He is available as a speaker on his column topics.