Tag Archives: climate change

Knowledge is Important

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We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.  T. S. Eliot

 

It is important to know that the space age did not create the environmental movement.  Much has been written about the affect of the “Earthrise” photo on the public consciousness in 1969 as the Earth Day movement got started.  Certainly the experiences of the Apollo astronauts looking back at a small blue earth in the distance contributed to the general knowledge that the earth is small, fragile, and in need of protection.  But the conservation movement anti-dates the space age by at more than a century.  Think of John Muir and Teddy Roosevelt in this country among the many who have been concerned about our planet.

 

Having properly noted those facts, however, we should remember that space exploration profoundly affects how we understand our environment, the weather, the climate, pollution, and the weighted affects of human and natural causes to changes in the world around us, both for good and for ill.

 

Any serious discussion of climate change, for example, relies extensively on satellite observations from space.  That much is clear to anyone who studies the topic.

 

However, an equally important affect is our understanding of how planetary atmospheres and climates work.  There are many predictions that are being churned out by global climate computer models which we need to understand. 

 

If all the doctors in history had one patient to study, they could scarely have a complete understanding of the vast complexity of medical science.  Similarly, those whose study is limited to only one planet would have an incomplete and biased view of how the oceans, atmosphere, solar affects, and human interaction all weave their complex interplay.

 

Planetary scientists have studied – at close range – planets with atmospheres and oceans, and planets with atmospheres and no oceans, planets with frozen oceans and no atmospheres, the atmosphere and workings of the sun, and many other intriguing and valuable iphenomena that builds up an understanding which is at the heart of the computer models that are of so much interest in the climate discussions of today. 

 

Predictions are only as good as the information and models that are used in making the predictions.  Better information is needed and better models are needed as well.  Space exploration informs both aspects.

 

How about a subtle story that you may not have heard? 

 

Scientists have known for over two hundred years that large meteorites or asteroids have periodically struck the earth.  The natural erosion forces at work on the earth’s surface – and underneath due to plate tectonics – have erased most of the craters.  Detecting large impact features on planet earth is not simple.

 

When the Apollo astronauts returned rocks from the moon in the late sixties and early seventies, one new class of rock that was incontrovertibly associated with impact craters were the shocked breccias.  From the study of rocks of another world, geologists learned much about the identification of the rocks associated with impacts.  Several types of rock that were not well understood, but which were noted as “interesting” became readily identified as impact shocked samples.

 

In the late seventies, geologists studying core samples obtained by the Mexican petroleum company Pemex, identified rocks coming from offshore rigs near the Yucatan as impact shocked rocks, sharing many characteristics with the lunar breccias.  Taken together with other subtle clues, the geologists mapped out a huge and previously unknown impact crater that they named Chicxulub.  Something big happened there about 65 million years ago.  Something that you should know about.  Something that might make you think about the big things that sometimes affect life on earth in profound ways.

 

Something we didn’t understand until we studied the rocks from another world.

 

Serendipity — Part 2 – a warning

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SERENDIPITY 

From the Merriam-Webster On-Line Dictionary:

Serendipity   ser·en·dip·i·ty  Pronunciation: -di-pə-tē noun Etymology: from its possession by the heroes of the Persian fairy tale The Three Princes of Serendip 1754

: the faculty or phenomenon of finding valuable or agreeable things not sought for; also : an instance of this
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Sometimes, when you look you find out things that you never expected to find.  Unfortunately, sometimes what you find out is not always agreeable; but maybe necessary.  Forewarned is forearmed, so the saying goes.  Dr. John Horack of Marshall Space Flight Center’s Science and Mission Systems office alerted me to an unusual discovery made by NASA in the jungles of Guatemala.
 
This is the story of a series of satellites and the ground based analysis of their data.  First of all, the satellites were not constructed to be an archeological tool. They were intended to monitor many things on the earth, in particular plant growth to help understand how agriculture and forestry could be improved.  To do this, the instruments lofted into space looked at various spectral bands in ways the human eye cannot see.  Flying over the Peten basin of Guatemala in the dry season, they collected data which amounted to plant health.  Ground processing with intricate computer codes extracted patterns from the raw data.  And these patterns meant something very interesting.
 
The Maya created a great civilization that lasted the better part of a millennium.  At the time they were unsurpassed in astronomy and mathematics, especially when compared to Europe, deep in its dark ages.  The Maya were on par with the great Arabian scientists and philosophers of the same era whose algebra is still bedevils schoolchildren.  The Mayan empire stretched across meso-america and their influence was felt by all peoples for a thousand miles north and south. 
 
But their civilization suddenly collapsed.  We don’t really know why.  Just collapsed.  No record of a war, perhaps it was a plague, but nobody knows.  Most of the Mayan ruins lie in the all but impenetrable forests of central America.  Archeologists suspect that as late as a decade ago, less than 1% of the Mayan ruins had been studied.  The Peten basin was the nexus of their homeland, today it is largely uninhabited and wild.  In the middle of what amounted to a resource desert, the Maya had built a huge concentrated metroplex.  The population density exceeded that of the most populated areas of China or India today.  Food production, water distribution, waste management were all the subject of intense planning and construction.  Until the day it was all abandoned.

 

Ground processing of satellite data during the region’s dry season detected subtle spectral differences in signatures from the canopy tops.  In regular patterns some of the flora was more stressed — imperceptible to the human eye — than the surrounding vegetation.  With GPS precision, archeological teams were sent to some of these places and discovered — ruins: aqueducts, buildings, temples, homes — an entire civilization mapped precisely by the change their foundations made to the soil. 
 
Recent computer modeling of the local climate may give some clues as to why this happened.  In the natural cycle there are periods which are drier and periods which are wetter.  With proper understanding and accomodation, humans have dealt with such cycles with reasonable inconvenience.  However, when the dry cycle hit central America in the 9th century, the Maya had deforested the entire region.  The computer models predict that temperatures rose significantly than would have been the case if the vegetation had been intact.  The hydrological cycle was interrupted because the moisture naturally exhaled by trees.  The models show the rains didn’t merely diminsh, they quit altogether.  Food production must have collapsed; the water system must have dried up when the reservoirs were no longer refilled.  Civilization as the Maya knew it came abruptly to an end.  And the people either died or walked away. 
 
When the European explorers came 500 years later, the Maya still existed in small pockets, but they were no longer a great civilization; just another native tribe which was swept away with the others.
 
So what is the lesson for us?  There is a lot of debate about global climate change these days.  I don’t know what you think about global climate change — is it happening or not, is it man made or not — and perhaps that debate is extraneous to the central history lesson of the Maya.  Here is the lesson:  if you don’t understand what you are doing to your neighborhood, bad things can happen.  Really bad things.  So learn, understand, and adjust accordingly. 
 
If we don’t learn anything else from the collapse of the Maya, that is probably enough. 
 
And nobody foresaw that we would figure this out by sending satellites into space. 
 
Serendipity — with a warning. 
 
 
 
 
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