sexta-feira, setembro 28, 2007

Últimas alterações climáticas

Because Arctic ice cover varies so much year to year, it can be dangerous to look at any one year and draw too much of a conclusion from it," said Waleed Abdalati, head of Goddard's Cryospheric Sciences Branch. "But this year, the amount of ice is so far below that of previous years that it really is cause for concern. The trend in decreasing ice cover seems to be getting stronger and stronger as time goes on." In September 2007, the Northwest Passage was ice-free for the first time since satellite records began. The passage is a direct route from Europe to Asia for ships traveling through the Arctic.
'Remarkable' Drop in Arctic Sea Ice Raises Questions
NASA Finds Greenland Snow Melting Hit Record High in High Places

sexta-feira, setembro 21, 2007

NASA Researchers Find Snowmelt in Antarctica Creeping Inland

"Persistent melting on the Ross Ice Shelf is something we should not lose sight of because of the ice shelf's role as a 'brake system' for glaciers," said Tedesco. "Ice shelves are thick ice masses covering coastal land with extended areas that float on the sea, keeping warmer marine air at a distance from glaciers and preventing a greater acceleration of melting. The Ross Ice Shelf acts like a freezer door, separating ice on the inside from warmer air on the outside. So the smaller that door becomes, the less effective it will be at protecting the ice inside from melting and escaping."

quinta-feira, setembro 13, 2007

Cut the head of the Beast

sexta-feira, setembro 07, 2007

Praise My Guru

Self-reinforcing feedback loops sometimes occur in nature (population blooms are always evidence of some sort of reinforcing feedback loop), but they rarely continue for long. They usually lead to population crashes and die-offs. The simple fact is that growth in population and consumption cannot continue unabated on a finite planet.

If the increased availability of cheap energy has historically enabled unprecedented growth in rates of the extraction of other resources, then the coincidence of Peak Oil with the peaking and decline of many other resources is entirely predictable.

Moreover, as the availability of energy resources peaks, this will also affect various parameters of social welfare:

  • Per-capita consumption levels
  • Economic growth
  • Easy, cheap, quick mobility
  • Technological change and invention
  • Political stability

All of these are clearly related to the availability of energy and other critical resources. Once we accept that energy, fresh water, and food will become less freely available over next few decades, it is hard to escape the conclusion that, while the 20th century saw the greatest and most rapid expansion of the scale, scope, and complexity of human societies in history, the 21st will see contraction and simplification. The only real question then is whether societies will contract and simplify intelligently or in an uncontrolled, chaotic fashion.

None of this is easy to contemplate. Nor can this information easily be discussed in polite company: the suggestion that we are at or near the peak of population and consumption levels for the entirety of human history and that it's all downhill from here is not likely to win votes, lead to a better job, or even make for pleasant dinner banter. Most people turn off and tune out when the conversation moves in this direction; advertisers and news organizations take note and act accordingly. The result: a general, societal pattern of denial.

The above text is an excerpt from Museletter #185 by Richard Heinberg