# Alterações climáticas



## ]ToRnAdO[ (12 Jul 2012 às 15:57)

Alterações climáticas: tempestades vão ser menos frequentes mas mais violentas

Publicado em 12 de Julho de 2012.

Investigadores da Universidade de Telavive, em Israel, acreditam que por cada 1ºC de aquecimento global haverá um aumento de 10% em relâmpagos. Estes cientistas, que estão a trabalhar na identificação de como as alterações climáticas poderão impactar o clima – nuvens, chuva ou relâmpagos – explicam que este aumento de relâmpagos pode ter consequências negativas e influenciar inundações, fogos ou danos em linhas eléctricas e infra-estruturas.

As conclusões, publicadas no Journal of Geophysical Research and Atmospheric Research, dizem que haverá menos tempestades, mas, como a actividade de relâmpagos subirá, estas serão mais intensas.
Segundo Colin Price, chefe do departamento de Geofísica, Ciências Planetárias e Atmosféricsa da Universidade de Telavive, estas conclusões têm como base uma modelagem em computador que foi comparada com exemplos reais, como o El Niño.

“Durante os anos do El Niño, que ocorreu no Oceano Pacífico, o sudoeste asiático tornou-se mais quente e seco. Há poucas tempestades, mas encontrámos 50% mais actividade relacionada com relâmpagos”, explicou Price.

Na verdade, segundo o cientista, as condições mais secas deveriam produzir menos relâmpagos. Ao invés, as poucas tempestades revelaram-se mais fortes e potentes.
Para além de tempestades mais intensas, o projecto concluiu que as alterações climáticas terão graves implicações em algumas partes dos Estados Unidos, no caso dos incêndios cuja origem serão os relâmpagos. Um clima mais seco levará também à rápida progressão dos fogos.

Paralelamente, também as inundações e queda de chuva violenta será mais espaçada – mas também mais intensa. Países como Espanha, Itália e a região do Médio Oriente serão os mais afectados.

Fonte: http://greensavers.sapo.pt/2012/07/...-vao-ser-menos-frequentes-mas-mais-violentas/


----------



## duncan (18 Jul 2012 às 14:03)

Boas vejam este artigo da Foprbes  do estudo dos dados recolhidos pelo satélite da NASA em relação à perda de calor para o espaço e calor retido. Interessante...

NASA satellite data from the years 2000 through 2011 show the Earth's atmosphere is allowing far more heat to be released into space than alarmist computer models have predicted, reports a new study in the peer-reviewed science journal Remote Sensing. The study indicates far less future global warming will occur than United Nations computer models have predicted, and supports prior studies indicating increases in atmospheric carbon dioxide trap far less heat than alarmists have claimed.

Study co-author Dr. Roy Spencer, a principal research scientist at the University of Alabama in Huntsville and U.S. Science Team Leader for the Advanced Microwave Scanning Radiometer flying on NASA's Aqua satellite, reports that real-world data from NASA's Terra satellite contradict multiple assumptions fed into alarmist computer models.



"The satellite observations suggest there is much more energy lost to space during and after warming than the climate models show," Spencer said in a July 26 University of Alabama press release. "There is a huge discrepancy between the data and the forecasts that is especially big over the oceans."

In addition to finding that far less heat is being trapped than alarmist computer models have predicted, the NASA satellite data show the atmosphere begins shedding heat into space long before United Nations computer models predicted.

The new findings are extremely important and should dramatically alter the global warming debate.

Scientists on all sides of the global warming debate are in general agreement about how much heat is being directly trapped by human emissions of carbon dioxide (the answer is "not much"). However, the single most important issue in the global warming debate is whether carbon dioxide emissions will indirectly trap far more heat by causing large increases in atmospheric humidity and cirrus clouds. Alarmist computer models assume human carbon dioxide emissions indirectly cause substantial increases in atmospheric humidity and cirrus clouds (each of which are very effective at trapping heat), but real-world data have long shown that carbon dioxide emissions are not causing as much atmospheric humidity and cirrus clouds as the alarmist computer models have predicted.

The new NASA Terra satellite data are consistent with long-term NOAA and NASA data indicating atmospheric humidity and cirrus clouds are not increasing in the manner predicted by alarmist computer models. The Terra satellite data also support data collected by NASA's ERBS satellite showing far more longwave radiation (and thus, heat) escaped into space between 1985 and 1999 than alarmist computer models had predicted. Together, the NASA ERBS and Terra satellite data show that for 25 years and counting, carbon dioxide emissions have directly and indirectly trapped far less heat than alarmist computer models have predicted.

In short, the central premise of alarmist global warming theory is that carbon dioxide emissions should be directly and indirectly trapping a certain amount of heat in the earth's atmosphere and preventing it from escaping into space. Real-world measurements, however, show far less heat is being trapped in the earth's atmosphere than the alarmist computer models predict, and far more heat is escaping into space than the alarmist computer models predict.

When objective NASA satellite data, reported in a peer-reviewed scientific journal, show a "huge discrepancy" between alarmist climate models and real-world facts, climate scientists, the media and our elected officials would be wise to take notice. Whether or not they do so will tell us a great deal about how honest the purveyors of global warming alarmism truly are.

James M. Taylor is senior fellow for environment policy at The Heartland Institute and managing editor of Environment & Climate News.
Also Read.


----------



## girassol (18 Jul 2012 às 15:04)

Boas!

Agora vou meter um pouco de lenha na fogueira:




> The Petermann Glacier grinds and slides toward the sea along the northwestern coast of Greenland, terminating in a giant floating ice tongue. Like other glaciers that end in the ocean, Petermann periodically calves icebergs. A massive iceberg, or ice island, broke off of the Petermann Glacier in 2010. Nearly two years later, another chunk of ice has broken free.





> “The floating extension is breaking apart,” said Eric Rignot of NASA's Jet Propulsion Laboratory and the University of California–Irvine. “It is not a collapse but it is certainly a significant event.”



http://earthobservatory.nasa.gov/IOTD/view.php?id=78556

Cumps


----------



## ecobcg (31 Jul 2012 às 10:31)

Mais um estudo sobre Alterações Climáticas:



> *EUA: Cientista antes cético reconhece que as Alterações Climáticas têm origem humana*
> Filipa Alves (31-07-2012)
> 
> Perante os resultado obtidos pela sua equipa, que comprovam as conclusões de estudos anteriores que tinha posto em causa, o Professor Richard Muller anunciou no New York Times ter ficado convencido de que não só o Aquecimento Global é uma realidade como também que o Homem é o principal responsável.
> ...


----------

