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Posts Tagged ‘Climate’

Search for Traces of Ancient Supernova in Antarctica

Posted by jase on July 18, 2009

Japanese scientists journeyed to Antarctica to recover evidence of alterations to Earth’s atmosphere caused in medieval times by supernovae recorded by scholars – including obscure Irish monasteries where monks later interpreted them signs of the Antichrist . No, this isn’t the plot of the next Dan Brown novel (or a Dan Brow fanfiction written by an X-Files addict): this is real science.

Supernovae release terrific amounts of energy, as in “If one happened too close, the planet would be sterilized” truly terror-inducing terrific.  Some of this energy is fired off as gamma rays, which can travel thousands of light-years and still pack enough of a punch after to alter the atmosphere – which is exactly what happened in 1006 and again in 1054, when gamma rays blasted the upper atmosphere and created spikes in NO3 levels.  There was also quite a lot of visible light, creating a star visible even during the day which was noted by various Chinese, Egyptian and even monastic records.

To access past records of the atmosphere, a team of Japanese scientists carefully extracted 122 meters of ice core from Antarctica.  Even better, to locate events on such a stretch of frozen time you use known volcanic atmosphere-altering events as reference points – in other words, these guys use exploding mountains as a ruler. 

The team found NO3 spikes at times corresponding to 1006 and 1054, as well as a mysterious unknown third event – and we remind you that this is not a movie, even though that sounds so much like a second act reveal leading to a lost city or something, we can practically see Nicolas Cage’s shocked expression.

Unlike any movie adventurer of the unknown, who has a tendency to steal/detonate every single relic they find, the Japanese team have also made things easier for anyone who follows them.  The unprecedented detail of their observations reveals a standard 11-year cycle in ice-core records, corresponding to the sunspot cycle. This will help future ice-core observers track the time of events.

These people look at timescales so huge that the pulsing of the sun itself is just the ticking of a clock.

Posted in Antarctica, Climate, Earth, Global Warming, Historic Events, Science, Southern Hemisphere | Tagged: , , , , , , , | Leave a Comment »

What Temperature is the Earth Supposed to Be?

Posted by jase on June 28, 2009

If we don’t get our act together and slash greenhouse gas emissions, the UN climate change panel tells us, average global temperatures could rise by as much as 10 degrees F. by the end of the century.

But would that really be so bad? Sure, much of the South would be unbearable during the summer months (as would many of those tropical countries), but think of all that beautiful real estate in Alaska that we’d open up! And many of us here in Boston would willingly trade a dozen or more 100-degree F. days each year to wear shorts and flip-flops through October. Less snow shoveling, more Frisbee tossing. What’s not to like?

Who decreed that average global surface temperatures have to stay at the 58 degrees F. or so that modern humans are used to? After all, we’ve experienced temperatures much higher than that in the past (by “we,” I mean multicellular organisms living a half-billion years ago), and we’ve also had our share of ice ages. What is the “right” temperature for the planet?

Climate-change deniers love posing this question (economist Mark W. Hendrickson asked it earlier this week in a Monitor op-ed), because it makes those who try to answer it sound sentimental and unscientific. There is no “supposed to be” in nature. It is what it is.

But the question also misses the point: The alarming thing about global warming is not how high the average temperature will be, but how fast it’s rising.

And it’s rising really fast, compared to historical temperature shifts. The planet’s surface has warmed about 1.4 degrees F. since 1880, most of it in the past 30 years. And it’s accelerating. According to Britain’s Met Office, which has been recording temperature data since 1850, the next 10 hottest years after 1998 were, in order, 2005, 2003, 2002, 2004, 2006, 2007, 2001, 1997, 2008, and 1995.

When the temperature shifts this rapidly, living things may not be able to keep up. For instance, many insects, birds, and mammals time their breeding and migration based on temperature, while the many species of plants that they eat time their growth according to the sunlight. When this synchronicity gets thrown off, animals arrive on the scene before their meal is ready, the plants don’t get their seeds propagated, and species start going extinct. Whether we like to admit it or not, humans are part of this ecosystem.

This has happened before. About 250 million years ago, 9 of 10 marine species and 7 out of 10 of terrestrial species suddenly went extinct in what paleontologists call “The Great Dying.” They don’t know exactly what caused this mass extinction, but in all major proposed scenarios – an asteroid impact, a giant volcanic eruption, and changes in the composition of ocean gases – it was the resulting shift in the earth’s climate that, by throwing ecosystems out of whack, ultimately did in these creatures. Indeed, climate changes played a major role in all of the mass extinctions in the planet’s history.

None of this is to suggest that global warming will wipe out humanity. Homo sapiens, while perhaps not always living up to its name, has proven itself to be a highly adaptable species so far. But if we continue to allow our atmosphere to rapidly destabilize, will we be able to provide enough food and water, much less a measure of prosperity, for most of the 8 or 9 billion people predicted to be living here by midcentury? Do we really want to find out?

Posted in Climate, Earth, Global Warming, Science | Tagged: , , , | Leave a Comment »