By combining a hurricane model and coupled ocean-atmosphere general circulation model to investigate the early Pliocene, Emanuel, Brierley and co-author Alexey Fedorov observed how vertical ocean mixing by hurricanes near the equator caused shallow parcels of water to heat up and later resurface in the eastern equatorial Pacific as part of the ocean wind-driven circulation. The researchers conclude from this pattern that frequent hurricanes in the central Pacific likely strengthened the warm pool in the eastern equatorial Pacific, which in turn increased hurricane frequency — an interaction described by Emanuel as a “two-way feedback process.”�The researchers believe that in addition to creating more hurricanes, the intense hurricane activity likely created a permanent El Nino like state in which very warm water in the eastern Pacific near the equator extended to higher latitudes. The El Nino weather pattern, which is caused when warm water replaces cold water in the Pacific, can impact the global climate by intermittently altering atmospheric circulation, temperature and precipitation patterns.The research suggests that Earth’s climate system may have at least two states — the one we currently live in that has relatively few tropical cyclones and relatively cold water, including in the eastern part of the Pacific, and the one during the Pliocene that featured warm sea surface temperatures, permanent El Nino conditions and high tropical cyclone activity.Although the paper does not suggest a direct link with current climate models, Fedorov said it is possible that future global warming could cause Earth to transition into a different equilibrium state that has more hurricanes and permanent El Nino conditions. “So far, there is no evidence in our simulations that this transition is going to occur at least in the next century. However, it’s still possible that the condition can occur in the future.”�Whether our future world is characterized by a mean state that is more El Nino-like remains one of the most important unanswered questions in climate dynamics, according to Matt Huber, a professor in Purdue University’s Department of Earth and Atmospheric Sciences. The Pliocene was a warmer time than now with high carbon dioxide levels. The present study found that hurricanes influenced by weakened atmospheric circulation — possibly related to high levels of carbon dioxide — contributed to very warm temperatures in the Pacific Ocean, which in turn led to more frequent and intense hurricanes. The research indicates that Earth’s climate may have multiple states based on this feedback cycle, meaning that the climate could change qualitatively in response to the effects of global warming.
thinkahol * on 23 Aug 11When Perry accuses Ben Bernanke of treachery and treason, his violent rhetoric ("we would treat him pretty ugly down in Texas") is scary in itself. But we shouldn't let that obscure Perry's substantive message - that neither Bernanke nor the Fed really deserve to exist, to control the US money supply, and to work towards a dual mandate of price stability and full employment. For the first time in living memory, someone with a non-negligible chance of winning the US presidency is arguing not over who should head the Fed, but whether the Fed should even exist in the first place. Looked at against this backdrop, the recent volatility in the stock market, not to mention the downgrade of the US from triple-A status, makes perfect sense. Global corporations are actually weirdly absent from the list of institutions in which the public has lost its trust, but the way in which they've quietly grown their earnings back above pre-crisis levels has definitely not been ratified by broad-based economic recovery, and therefore feels rather unsustainable. Meanwhile, the USA itself has undoubtedly been weakened by a shrinking tax base, a soaring national debt, a stretched military, and a legislature which has consistently demonstrated an inability to tackle the great tasks asked of it. It looks increasingly as though we're entering Phase 2 of the global crisis, with 2008-9 merely acting as the appetizer. In Phase 1, national and super-national treasuries and central banks managed to come to the rescue and stave off catastrophe. But in doing so, they weakened themselves to the point at which they're unable to rise to the occasion this time round. Our hearts want government to come through and save the economy. But our heads know that it's not going to happen. And that failure, in turn, is only going to further weaken institutional legitimacy across the US and the world. It's a vicious cycle, and I can't see how we're going to break out of it.
