Thursday, February 17, 2011

The Wetter World of Greenhouse Warming: Now Here!




Page from World Book Science Annual for 1982 showing effects of sea level rise for Florida and Antarctica, as well as expected temperature increases in different parts of the world. It is interesting that the article, 'Warmer, Wetter Weather Ahead?', basically forecast the drenching rains, deluges and severe snow storms we've been seeing recently....nearly 30 years BEFORE they transpired!





Graph from The Financial Times showing rise in sea level since about 1870.



Even as the Repukes perform their usual tricks to halt the EPA from implementing CO2 emissions -limiting regulations (since congress continues to sit on its collective ass), the evidence mounts that we're entering a high precipitation world as the warming planet we inhabit evolves toward a runaway Greenhouse scenario.

This was brought to the fore as I picked up an old World Book Science Yearbook for 1982 and perused the lead article: 'Warmer, Wetter Weather Ahead?' by W. Lawrence Gates. The extensive article, including color graphics (see image) projected that the continued burning of fossil fuels would unbalance the natural chemical cycle and thereby heat the Earth, redistributing precipitation, as it caused massive flooding and possible sea level rise.

Now, two papers published in the journal Nature appear to bear those projections - made nearly 30 years ago - out. In one paper, by Francis Zwiers and a team based at Environment Canada in Toronto, it was found that human-originated emissions of carbon dioxide and other greenhouse gases (e.g. methane) helped trigger an increase in extreme rainfall events in North America over the second half of the 20th century.

Zwiers and his team gathered 50 years of rainfall statistics and compared those observations to predictions made via computer simulations of the 20th century climate. The latter included the wrming impact of the billions of tons of CO2 that human society has pumped into the atmosphere, of which barely 35% had been absorbed by the oceans - as of the 1982 World Book article.

Zwier's study as reported in Nature found that "the increase in deluges cannot be explained by natural internal fluctuations alone". In other words, only by factoring in the additional greenhouse gases can the precip increase be fully accounted for. As pointed out in the World Book article, the explanation rest on simple physics: Warmer air holds more water vapor than cooler air. This means that if and when rainfall is triggered, more moisture-laden air will be involved and deluges will result. We already saw some of that in Pakistan and other places this past summer and in Queensland, Australia earlier this year.

The second study, by an international team of researchers led by Pardeep Pall of the University of Oxford, England, found that "human (greenhouse) gas emissions substantially increased the odds of floods occurring in what had been the record wet autumn of 2000". Those floods inundated the UK that year and were the most severe recorded since at least 1766.

Pall's team's conclusions emerged from two sets of many thuosands of computer climate-weather simulations. The first simulated the atmosphere in its real state, loaded with all the additional CO2 humans have pumped into it since the Industrial Revolution, while the second simulated a "parallel world" in which no extra CO2 had been added to the atmosphere.

Pall et al found that the odds of massive floods occurring in the latter simulation were about half those of the former. Interested people can learn more by going to:

http://www.climateprediction.net/

In the second graphic, from an issue of The Financial Times from six months ago, six sets of data are used to show the sea level rise since 1870. As can be discerned, by 2000 the level rise had just passed 55 mm or about 2.0 inches. The sea level rise so far is not too dramatic and is inconsequential except for islands like Vanuatu for which even small differences can be catastrophic in the event of rogue waves, or storm surges. As far as the sea rise needed to inundate most of the state of Florida (as depicted in the 1982 World Book graphic) one would need at least a 5m (or 5000 mm) increase. This isn't likely unless the Greenland ice sheet collapses and melts, though there are already signs of massive fracturing and leakage of melted ice from those fractures.

Stay tuned! In the meantime, let's hope the EPA can save us all some time by getting those greenhouse emission regulations into effect.

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