Unlike most apparently intractable proble
ms, which have a tendency to go away when examined closely and analytically, the climate change predicament just seems to get bigger and scarier the more we learn about
it.
Now we discover that not only are the oceans and the atmosphere conspiring against us, bringing baking temperatures, more powerful storms, floods and ever-climbing sea levels, but the crust beneath our feet seems likely to join in too.
Looking back to other periods in our pla
net's history when the climate was swinging about wildly, most notably during the last ice age, it appears that far more than the weather was affected. The solid earth also became restless, with an increase in volcanic activity, earthquakes, giant submarine landslides and tsunamis. At the rate climate change is accelerating, there is every prospect that we will see a similar response from the planet, heralding not just a warmer future but also a fiery one.
Several times in the past couple of million years the ice left its polar fastnesses
and headed towards the equator, covering much of the world's continents in ice sheets over a kilometre thick, and sucking water from the oceans in order to do so. As a consequence, at times when the ice was most dominant, global sea levels were as much as 130m lower than they are today; sufficient to e
xpose land bridges between the UK and the continent and Alaska and Russia.
Each time the ice retreated, sea levels shot up again, sometimes at rates as high as several metres a century. In the mid 1990s, as part of a study funded by the European Union, we discovered that in the Mediterranean region there was a close correlation between how quickly sea levels went up and down during the last ice age and the level of explosive activity at volcanoes in Italy and Greece.
The link was most obvious following the retreat of the glaciers around 18,000 years ago, after which sea levels jumped back up to where they are today, triggering a 300% increase in explosive volcanic activity in the Mediterranean in doing so. Further evidence for a flurry of volcanic action at this time comes from cores extracted from deep within the Greenland ice sheet, which yield increased numbers of volcanic dust and sulphate layers from eruptions across the northern hemisphere, if not the entire planet.
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But how can rising sea levels cause volcanoes to erupt? The answer lies in the enormous mass of the water pouring into the ocean basins from the retreating ice sheets. The addition of over a hundred metres depth of water to the continental margins and marine island chains, where over 60% of the world's active volcanoes reside, seems to be sufficient to load and bend the underlying crust.
This in turn squeezes out any magma that happens to be hanging around waiting for an excuse to erupt. It may well be that a much smaller rise can trigger an eruption if a volcano is critically poised and ready to blow.
Eruptions of Pavlof volcano in Alaska, for example, tend to occur during the winter months when, for meteorological reasons, the regional sea level is barely 30cm (12in) higher than during the summer. If other volcanic systems are similarly sensitive then we could be faced with an escalating burst of volcanic activity as anthropogenic climate change drives sea levels ever upwards.
Notwithstanding the recent prediction by the Intergovernmental Panel on Climate Change (IPCC) that sea levels in 2100 will be a measly 18-59cm (7-23in) higher, Jim Hansen ?eminent climate scientist and director of NASA's Goddard Institute for Space Studies ?warns that we could see a one to two metre rise this century and several more in the next. Other climate scientists too, forecast substantially greater rises than the IPCC, whose prediction excludes any consideration of future changes in polar ice sheet behaviour. A worst-case scenario could see a return to conditions that prevailed around 14,000 years ago, when sea levels rose 13.5 metres (44ft) - the height of a three-storey house - in the space of about 300 years.
Such a dramatic rise in coming centuries would clearly spell catastrophe for our civilisation, with low-lying regions across the planet vanishing rapidly beneath the waves. Just a one metre (3.28ft) rise would threaten one third of the world's agricultural land, two metres (6.56ft) would make the Thames flood barrier redundant and four metres (13.12ft) would drown the city of Miami, leaving it 37 miles (60km) off the US coast.
As sea levels climb higher so a response from the world's volcanoes becomes ever more likely, and perhaps not just from volcanoes. Loading of the continental margins could activate faults, triggering increased numbers of earthquakes, which in turn could spawn giant submarine landslides. Such a scenario is believed to account for the gigantic Storegga Slide, which sloughed off the Norwegian coast around 8,000 years ago, sending a tsunami more than 20 metres (66ft) high in places across the Shetland Isles and onto the east coast of Scotland. Should Greenland be released from its icy carapace, the underlying crust will start to bob back up, causing earthquakes well capable of shaking off the huge piles of glacial sediment that have accumulated around its margins and sending tsunamis across the North Atlantic.
The Earth is responding as a single, integrated system to climate change driven by human activities. Global warming is not just a matter of warmer weather, more floods or stronger hurricanes, but is also a wake-up call to Terra Firma. It may be no coincidence that one outcome of increased volcanic activity is likely to be a period of falling temperatures, as a veil of volcanic dust and gas reduces the amount of solar radiation reaching the surface. Maybe the Earth is trying to tell us something. It really would be worth listening before it is too late.How many global warmings have occurred in the past?There have been countless warmings and coolings of the planet during it's existence.How many global warmings have occurred in the past?CountlessHow many global warmings have occurred in the past?one
they called it a
FLOODHow many global warmings have occurred in the past?1500 year cycle.How many global warmings have occurred in the past?so, how many of these ancient climate changes where humans responsable for?
None, if the climate changes it is part of the normal change the planet goes through and there is nothing we can or should do about it because we will most likely just make things worse.How many global warmings have occurred in the past?I do believe that man is a contributor to global warming.. so don't think I'm trying to knock the theory with this.. but did you know they believe that our species, the homo-sapien sapien, arose from these periods of massive weather change.. our bodies are designed to adapt to all weather conditions.. from very hot to very cold.. this is why we overtook the neanderthals .. they were better designed for cold weather.. but only for cold weather.. they could not adapt to change as we could.
global warming is a problem.
we should address it and do our best to take care of our part.
but it won't be the end of mankind.. we were made to adapt to this type of thing as a species.How many global warmings have occurred in the past?What caused all the others? My dear ol Grandad used to say %26quot;If you don't stand for something, you'll fall for anything.%26quot; And you liberals hate America so much that you're easy prey for the scam artisit.
The biggest segment of
data you man-made global warmites don't figure in is weather because you can't, it's to complicated. The computer model is flawed that way, and it's causes the model to drift.
BTW what happened to all of the Hurricanes we are supposed to be having. So, much for your %26quot;scientists%26quot; predictions.How many global warmings have occurred in the past?As you point out this has happened before and presumably not due to methane from the Woolly Mammoths. What makes you think that whatever we do could stop this any more than we can stop tornadoes and earthquakes?How many global warmings have occurred in the past?Yes, global warming has happened in the past. But every scientist studying this issue also knows that it hasn't happened at the rate of speed it is happening now. And, they also know that humans are causing it. There is no debate about this. This is now considered scientific fact.
And, you forgot to add one issue that isn't being talked about much but it really is a huge issue. And, that is the amount of carbon dioxide trapped underneath the oceans from rotting animals and plants. And, there is ALOT! the fact that the waters are warming up makes that carbon dioxide start bubbling and it warms as well. Carbon rises when warmed and if that carbon dioxide warms enough, it will surface to the top of the ocean and it WILL kill everthing in it's path, animal human and vegetation. This is no small thing. This is massive and it covers most of the deep ocean. In otherwords, this carbon dioxide mass threatens life on the entire planet.How many global warmings have occurred in the past?There will always be change in the warming and cooling, always has, and always will be...Due to the way God made the earth, like this...
%26quot;In the atmosphere, heat is transferred by one of three processes: conduction, convection, or radiation. Conduction is the movement of heat by and through a substance by stimulation of its molecular activity without any movement of the matter itself. the ability of substances to conduct hear varies considerably. For example , the handle of a solid metal spoon heats rapidly when the other end is immersed in a hot liquid, whereas the handle of a wooden spoon remains cool. This difference comes about because wood is a relatively poor conducter. The atmosphere is also a poor conductor, , so conduction plays a minor role in the warming or cooling of air. Of much greater importance in weather events is convection, or the transport of heat by the movement of parcels of air. Convection is usually described as taking place vertically. Fair-weather cumulus clouds, for example, are caused by rising air currents. Air heated at the surface of the earth tends to rise as an invisible column through surrounding cooler air. The rising column continues to cool in its ascent until it reaches its dew point, or saturation temperature,. At this point, also called the condesation level , water vapor in the rising air becomes liquid and is visible as a cloud. Most atmospheric heat originatees on the sun and arrives by radiation, or the invisible transfer of heat by rays of various wavelengths. The conducting medium is unaffected by the passage of radiative heat through it, but the terminal object of the rays absorbs, scatters, or reflects the heat. Of the solar radiation arriving at the top of the atmosphere, only about 50 percent is absorbed by the surface of the earth. About 20 percent is absorbed in the air by molecules, particles, and clouds; 27 percent of the total is reflected back into outer space by cloud tops and air molecules. The remaining 3 percent is reflected directly back to space by the earth's surface. Although the earth as a whole absorbs about as much heat as it loses, the rates of absorption and loss differ according to latitude,. In the tropics and equatorial regions, where the daytime sun passes nearly overhead, more heat is received than lost. the opposite is true for more poleward latitudes, where sunlight strikes the ground at lower angles. This imbalance of heat in various parts of the globe drives the winds and ocean currents, which act as giant heat pumps, tansferring warm air or water form the latitudes poleward, and returning cold air and water to the tropics.%26quot;
As you can see, the earth is in balance, and will always have different shifts in weather patterns from time to time, but it will always basically balance over time, that is why the earth tilts during spring and fall, giving us summer and winter, in the northerly reaches and southerly reaches, and staying the same in the center/equatorial latitudes.How many global warmings have occurred in the past?Why should you care you are rich , So it will not effect you,
just turn your AC up
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