It is raining in Adelaide because the tropical weather inflow from the Coral Sea, that has been causing the huge floods covering most of Queensland has finally reached this area. The last time we experienced this weather pattern was in 1974 and was the cause of the worst flooding up to then. This flooding is far worse and is recognized now as the worst since the European settlement of Australia. La Nina, the mischievous sister to El Nino, is the culprit. This occurs when the sea temperature Northeast of Australia, in the Coral Sea, is abnormally high.
Like as not, you are more concerned with your own weather. However, you can access amazing videos of the Queensland floods on ABC News. Many of these videos have been taken by folk caught in the flooding, using their mobile phone cameras. As an aside, this is part of the emergent social networking phenomenon. The videos are astonishing. Seventy five percent of Queensland has been declared a disaster area, an area twice the size of the State of Texas. The flooding extends into adjoining northern New South Wales. Moreover, heavy rain associated with the weather pattern I am experiencing is also causing serious flooding in the State of Victoria.
Like the Mississippi River, which drains much of interior USA, the Darling/Murray River system drains a huge area of Australia, extending from the western slopes of the Great Dividing Range, the long backbone of the eastern seaboard. The Murray empties into the Southern Ocean some 70 miles South of Adelaide. For the last two decades, this river system has been dying due to droughts and abusive irrigation practices. Almost dead at year's end, the river is now reviving though the gigantic volumes of water transfusing it. As someone once quipped, its an ill flood that flows no one good.
Working in tandem, the terrible weather twins, El Nino and La Nina, have an enormous effect on the weather on both sides of the Pacific Ocean. They have but little effect on the weather East of the Rockies and in Northern Europe. As I mentioned in another place, abnormal snow coverage in the Siberian Autumn and on into Winter seems the best explanation of the terrible Winter storms that have afflicted Northeastern America and Northern Europe. One of my correspondents remarked that it looks as if the Russians have won the "Cold War" after all! If you look down on Earth from above the North Pole, by using Google Earth, you will see how vast an area is Siberia.
All three factors in the weather (the Terrible Twins and Fall Siberian snow cover) have a main cause...warming of the oceans. A huge network of ocean sensors, deployed over the last five years, indicate the the rate of warming of the oceans is accelerating. The ocean currents do most of the work of distributing the heating from the sun between the hot equator and the cold poles. The remainder is done by the atmosphere though jets streams and trade winds. The oceans constitute a huge heat sink and their temperature is more or less regulated by evaporation. Winds carry this water vapor to the land masses. As these currents of moist air rise over the land they release water by condensation causing rain or snow to fall, just where being dictated by the upper level jet streams.
Last year, and in other years, rather more snow than usual fell over Siberia. The cold air above the snow forms huge hump deflecting the northerly jet streams more South and causing the bleak conditions in Northern America and Europe. This effect has only recently been incorporated into climate models and has been shown to have excellent explanatory power. If the model is correct, expect unusually cold conditions in these areas during December to March every few years.
Well what about global warming? If the 'green house' effect of the rising carbon dioxide and methane levels in the atmosphere causes extra heating of the oceans, we must expect more extreme weather patterns. We are between Ice Ages so of course the climate is warming. All the previous Ice Ages have been separated, according to' climate archeologists', by warm periods most with weather patterns far more variable than our present warm period. In the rather short history of hominids, we have suffered several periods of widespread glaciation with devastating effects on us, two or so in our most recent history. Most, if not all, of these glaciated periods have been presaged by a swift rise in average global temperatures and then the world went very cold quite quickly.
Our ancestors had not the science to understand even a glimmer of the vast processes that governed their existence. We are just beginning to have some understanding and by the time all the members of the various juries interested in this have agreed on the science, most likely it will be to late to take effective actions.
Do I think that human actions add to the natural effect of interglacial warming. Absolutely...one cannot burn up millions of years of accumulated fossil carbon in one huge, relatively brief bonfire, releasing all that carbon into the atmosphere, without dangerously tinkering with natural processes we understand little as yet. At some point the natural negative feed back loops that keep earth's temperature relatively stable will be overcome by a riot of positive feedbacks that will unhinge the benign conditions we think imperturbable.
Am I pessimistic about our ability to avert possible disaster. You bet I am. The complex warp and weft of intertwining forces, political, industrial, scientific, the natural skepticism that that the cry of "wolf" is not just a bad joke, and the desire of the well-off nations to preserve their comfort will most likely weave a carpet of inaction leading to very difficult times for we humans and the unfortunate other species that did no more than make our world beautiful.
Simple, plain economics may be the only factor that may avert this but not without great troubles to many. When oil ran to $140 or so a barrel, diesel fuel became so expensive as to curtail mining operations. Following the disastrous BP/Horizon/Haliburton oil rig accident off Louisiana, getting new oil will be increasingly expensive. The rising consumption of fossil fuels in developing counties will not slow much and overall global consumption will continue to rise while production, at best, remains stable. Fossil fuel will become very expensive and the great industrial economies will inevitably slow. Historically, when coke became scarce coal took over. When oil was cheap, it took over from coal, setting up our present oil-based global economies. Natural gas looks good, for a short while, to take over from oil and coal to fuel the worlds slowing energy consumption in a carbon conscious world. Nuclear power will likely be the world's last energy resort.
With a lot of luck, most of the fossil fuel left in the earth may yet remain there but don't hold your breath waiting for this to happen.
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