Bekijk Volledige Versie : Koud
Kort buitenlands nieuws
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GARCHING Astronomen in Duitsland hebben
een foto vrijgegeven van de volgens hen
koudste plaats in het heelal.Het is de
Boemerang Nevel,5000 lichtjaren van de
Aarde verwijderd.Metingen wijzen uit
dat het er -272 graden Celsius is.
Mijn badkamer is 's ochtends als ik ga douchen NOG kouder!
Mijn buurvrouw is ook zo koud :Iluvu: .
Marsipulami
20-02-03, 17:57
Geplaatst door Mark
Mijn badkamer is 's ochtends als ik ga douchen NOG kouder!
Zet dan de verwarming aan gierige Hollander :fpiraat:
Geplaatst door Marsipulami
Zet dan de verwarming aan gierige Hollander :fpiraat:
Niet nodig, wij ten noorden van de grote rivieren kunnen we wel tegen een stootje. Mietje.
Inderdaad. Waar blijft die kleine ijstijd door het broeikaseffect???
http://www.whoi.edu/institutes/occi/climatechange_wef.html
Are ‘little ice ages’ and ‘megadroughts’ possible?
Scientists are investigating whether changes in ocean circulation may have played a role in causing or amplifying the “Little Ice Age” between 1300 and 1850. This period of abruptly shifting climate regimes and more severe winters had profound agricultural, economic, and political impacts in Europe and North America and changed the course of history.
During this era, the Norse abruptly abandoned their settlements in Greenland. The era is captured in the frozen landscapes of Pieter Bruegel’s 16th-century paintings and in the famous painting of George Washington’s 1776 crossing of an icebound Delaware River, which rarely freezes today. But the era is also marked by persistent crop failures, famine, disease, and mass migrations. “The Little Ice Age,” wrote one historian, “is a chronicle of human vulnerability in the face of sudden climate change.”8
Societies are similarly vulnerable to abrupt climate changes that can turn a year or two of diminished rainfall into prolonged, severe, widespread droughts. A growing body of evidence from joint archaeological and paleoclimatological studies is demonstrating linkages among ocean-related climate shifts, “megadroughts,” and precipitous collapses of civilizations, including the Akkadian empire in Mesopotamia 4,200 years ago, the Mayan empire in central America 1,500 years ago, and the Anasazi in the American Southwest in the late 13th century.9
Rapid changes in ocean circulation associated with the abrupt North Atlantic cooling event 8,200 years ago have been linked with simultaneous, widespread drying in the American West, Africa, and Asia.10 Regional cooling events also have been linked with changes in the Southwest Asian monsoon, whose rains are probably the most critical factor supporting civilizations from Africa to India to China.11
What future climate scenarios should we consider?
The debate on global change has largely failed to factor in the inherently chaotic, sensitively balanced, and threshold-laden nature of Earth’s climate system and the increased likelihood of abrupt climate change. Our current speculations about future climate and its impacts have focused on the Intergovernmental Panel on Climate Change, which has forecast gradual global warming of 1.4° to 5.8° Celsius over the next century.
It is prudent to superimpose on this forecast the potential for abrupt climate change induced by thermohaline shutdown. Such a change could cool down selective areas of the globe by 3° to 5° Celsius, while simultaneously causing drought in many parts of the world. These climate changes would occur quickly, even as other regions continue to warm slowly. It is critical to consider the economic and political ramifications of this geographically selective climate change. Specifically, the region most affected by a shutdown—the countries bordering the North Atlantic—is also one of the world’s most developed.
The key component of this analysis is when a shutdown of the Conveyor occurs. Two scenarios are useful to contemplate:
Scenario 1: Conveyor slows down within next two decades.
Such a scenario could quickly and markedly cool the North Atlantic region, causing disruptions in global economic activity. These disruptions may be exacerbated because the climate changes occur in a direction opposite to what is commonly expected, and they occur at a pace that makes adaptation difficult.
Scenario 2: Conveyor slows down a century from now.
In such a scenario, cooling of the North Atlantic region may partially or totally offset the major effects of global warming in this region. Thus, the climate of the North Atlantic region may rapidly return to one that more resembles today’s—even as other parts of the world, particularly less-developed regions, experience the unmitigated brunt of global warming. If the Conveyor subsequently turns on again, the “deferred” warming may be delivered in a decade.
What can we do to improve our future security?
Ignoring or downplaying the probability of abrupt climate change could prove costly. Ecosystems, economies, and societies can adapt more easily to gradual, anticipated changes. Some current policies and practices may be ill-advised and may prove inadequate in a world of rapid and unforeseen climate change. The challenge to world leaders is to reduce vulnerabilities by enhancing society’s ability to monitor, plan for, and adapt to rapid change.
All human endeavor hinges on the vicissitudes of climate. Thus, the potential for abrupt climate change should prompt us to re-examine possible impacts on many climate-affected sectors. They include: agriculture; water resources; energy resources; forest and timber management; fisheries; coastal land management; transportation; insurance; recreation and tourism; disaster relief; and public health (associated with climate-related, vector-borne diseases such as malaria and cholera).
Developing countries lacking scientific resources and economic infrastructures are especially vulnerable to the social and economic impacts of abrupt climate change. However, with growing globalization of economies, adverse impacts (although likely to vary from region to region) are likely to spill across national boundaries, through human and biotic migration, economic shocks, and political aftershocks, the National Academy of Sciences (NAS) report stated.
The key is to reduce our uncertainty about future climate change, and to improve our ability to predict what could happen and when. A first step is to establish the oceanic equivalent of our land-based meteorological instrument network. Such a network would begin to reveal climate-influencing oceanic processes that have been beyond our ability to grasp. These instruments, monitoring critical present-day conditions, can be coupled with enhanced computer modeling, which can project how Earth’s climate system may react in the future. Considerably more research is also required to learn more about the complex ocean-air processes that induced rapid climate changes in the past, and thus how our climate system may behave in the future.
The NAS report is titled Abrupt Climate Change: Inevitable Surprises. Climate change may be inevitable. But it is not inevitable for society to be surprised or ill-prepared.
'Shocking' discovery boosts chance of life on Europa
09:38 21 February 03
NewScientist.com news service
Scientists simulating meteorite impacts on the frozen oceans of Europa have made an electrifying discovery, which raises the chances of finding life on Jupiter's moon.
Jerome Borucki, at the NASA Ames Research Center in California, and his colleagues fired aluminium bullets into a block of ice. They found that when the bullet impacted, sensors embedded in the ice detected an electric shock. A second, and much larger, electrical discharge was observed a few moments later.
A shell of ice many kilometres thick encases the surface of Europa and scientists speculate that liquid water - and therefore life - might lie beneath. Evidence for the presence of the molecular building blocks for life comes from the yellow-brown stains seen on the ice by the Galileo probe.
"Europa is a high priority target for exploration because the key ingredients for life seem to be there. But even if you have the ingredients, the question is, is there a spark that creates the first organic molecules?" says Ron Greeley, a planetary scientist at the Arizona State University.
Borucki's bullet experiments suggest meteorite impacts might have provided that spark. The electric shock had gone undetected because no-one had put sensors below an impact crater before, he told New Scientist. The team think the current is caused by the movement of protons as the ice cracks.
Methane and ammonia
In the 1950s, Stanley Miller, now at the University of California in San Diego, showed that shooting an electric current through a mixture of water, methane and ammonia created complex organic molecules. Amino acids, the building blocks of proteins, were among the products.
Methane and ammonia are likely to be present in Europa's ice and the energy pumped into the ice by a meteorite impact will melt it. Shock this mixture with electricity, says Borucki, and complex molecules should form.
But this still needs to be tested in the laboratory. So far the experiments have used only pure water ice, cooled to a chilly -196°C to simulate conditions on Europa.
The bullets used are about a centimetre across and were fired at the ice at a speed of six kilometres per second. This is the equivalent to a kilometre-sized asteroid crashing into the moon at about 24 km/s.
"We do see a handful of very large craters on Europa, and there would have been a lot of energy associated with those," comments Greeley. "These new results are exciting."
Greeley has been appointed by NASA to set the scientific priorities of Jupiter's Icy Moon Orbiter. This probe, which has recently been allocated funding, will visit Europa and two of Jupiter's other moons, Callista and Ganymede. A lander may be sent to the surface of the Europa to look for organic matter. But it will be a long wait - Greenley estimates the earliest launch date for the mission to be 2011.
Journal reference: Journal of Geophysical Research - Planets (Vol 107, p 24)
Jenny Hogan
http://www.newscientist.com/news/news.jsp?id=ns99993421
Geplaatst door Marsipulami
Zet dan de verwarming aan gierige Hollander :fpiraat:
Het is, zoals mrz zou zeggen, een paradox Mars.... De centrale verwarming gaat hier 's nachts uit. Als ik op ben kan ik de verwarming aanzetten maar ja ik moet dan toch gelijk douchen dus het heeft geen zin.
Sorry maar dat zou ik geen paradox noemen hoor. Dat is gewoon een kwestie van kiezen wat eerder op te staan :D
Tenzij het feit dat je de verwarming aanzet tot gevolg heeft dat er meer warm water voor de douche zou zijn, dan kom je beetje in de buurt.
pa·ra·´dox (de ~ (m.))
1 schijnbare tegenspraak [b.v. het geluid van de stilte, vele eersten zullen de laatsten zijn]