The day after Tomorrow
This is the title of a 2004 film that related about the sudden arrival of the fifth Quaternary glaciation. The film has the same rigor that 2012 film: none; but unlike 2012 where it exposed an improbable situation even with the entry conditions of film, the day after it presents a realistic situation and the probable events, while exaggerated developing the script and the plot is pathos. Like every movie has a happy ending entirely unrealistic because the reduction of a third of the area who have to live half of the 7,000 million inhabitants probably end up with a war for the remaining land (in this context Is it sure that Mexico will be able to contain 150 million evacuees at the border, as shown in the film, until you write off debt before wile evacuation is doing by second largest and technical army in the world? and why we do it extends to China Russia, UK, France, Japan ...).
I don’t what to speak about the movie but the real possibility of a new ice age that would change in the climate began to suffer. It's hard to hold in front summer so hot that the end of this process will be to see penguins on the Mediterranean coast. In fact nobody gets too agree and the arguments that I explain are as valid as others argue the opposite, both are helping us do nothing, not to stop and change else to prepare.
The main argument is that we live in the fifth ice age known. During Earth's history we know five ice ages: from 2,000 million years before now (Mybn) until 570 Mybn known three periods snowball where it is believed that the planet was completely frozen, as well as between 330 and 260 Mybn known as Carboniferous, and since 30 Mybn the Cenozoic that is the current. We are currently in an interglacial period of the Cenozoic ice age, and the interglacial periods are relatively short between 10,000 and 15,000 years.
To clarify that it was glaciation and ice are two terms that are used interchangeably to refer to two different things but they are related and this creates some confusion. When I say Ice Age I mean a long period of time, tens of millions of years or more, the planet where global temperatures are low enough to support the existence of permanent ice. And I mean glaciation between short periods of thousands of years to hundreds of thousands, usually within an ice age; temperatures are much lower than in the surrounding periods. This distinction is not equal for everyone and especially Anglo-Saxon authors usually the terms are rotated. I should also mention that our current period mild and pleasant climate is unusual that we have been fortunate to enjoy their humanity 140,000 years of existence has only enjoyed this climate about 20,000 years divided into two periods.
So why can we say that we are still in the middle of the ice age? Well the main reason is that the factors that have caused and maintained it, remain enough. The orography plays an important role in local climates, thus the distribution of landmasses on the planet affects the global climate. In the Carboniferous and Cenozoic match in the existence of a continent at the South Pole and the North Pole also in the Carboniferous and almost blocking the general trends in Cenozoic North Pole. The continents at the poles prevent the arrival of ocean currents that carry energy from the equator and it causes the polar snow cover which makes them more reflective that back energy to space; on the other hand if earth has the continents in poles then they aren’t at the equator, and the water is more reflective than the ground, water dominates equator also increasing energy back into space. Orographic changes are very slow and hence the Carboniferous lasted 90 million years and probably similar time will need earth that Antarctica leaves the South Pole. The other argument is to compare the actual temperature with the temperature outside the Carboniferous or Cenozoic, much higher in any latitude where the temperature of the sea water was from 4 to 15 C above current averages (the second is at the poles). The existence above poles of permanent ice indicates that we have not far to the ice age.
Another argument is the fragility of the climate of Western Europe. Just look at the latitude of Lisbon and compare the climate of cities with the same latitude as Seoul and Washington, and northwest Europe coincides with Tasmania and Patagonia. This difference is due to the warm water from the equator and that drives the Thermohaline circulation. The passage of hot water northwards is possible only over the Atlantic Ocean to the Pacific (Bering Strait) is very shallow streams having general circulation. But this hot wedge rises far north and westerly winds drive the heat coming through Europe. This current depends on the salinity of the water, and in this time of rising global temperatures is causing a thaw, which provides fresh water to the ocean surface. If you reduce the surface salinity of the Atlantic Thermohaline circulation not raise both north causing a drop in temperatures in Europe and in turn the entire northern half of the hemisphere continental because ice rising again and that the albedo* triggers the temperatures drop (read feedback where a more complete reasoning).
For the moment though many glaciers have retreated, the salinity of the water has not been affected much. This is because on the one hand that almost all ice of Greenland remains intact, and on the other hand most water melted has gone to the Arctic and it's trapped there. Fresh water trapped in the Arctic and its problems are treated at the finish of the tract North Pole ice can provoke a new ice age whst is a time bomb. Greenland is another bomb. Satellite images taken during the summer showed that mechanical consistency begins to break and if weather continues warming, as expected, this will start to melt quickly. As first case like the other provide large quantities of fresh water into the Atlantic Ocean.
Lastly is global warming. It could be that really be able to reverse the current ice age, but it is unlikely. As well as expose the drop that make the glass overflow, it is likely that global warming is only part of the current climate fluctuation, of course it altered by us. Surely if we had not blurned so many fossil fuels would be beginning of a time similar to that of classical Greece and the early Roman Empire. But considering that we have reached the limit of the short interglacial periods could be just the return to them, which would be a little advanced optimum**. It may seem strange but the end of the last ice age did the same but negative: a warm period almost ended abruptly for a very short cold and also ended abruptly that gives way to the interglacial we live.
I don’t what to speak about the movie but the real possibility of a new ice age that would change in the climate began to suffer. It's hard to hold in front summer so hot that the end of this process will be to see penguins on the Mediterranean coast. In fact nobody gets too agree and the arguments that I explain are as valid as others argue the opposite, both are helping us do nothing, not to stop and change else to prepare.
The main argument is that we live in the fifth ice age known. During Earth's history we know five ice ages: from 2,000 million years before now (Mybn) until 570 Mybn known three periods snowball where it is believed that the planet was completely frozen, as well as between 330 and 260 Mybn known as Carboniferous, and since 30 Mybn the Cenozoic that is the current. We are currently in an interglacial period of the Cenozoic ice age, and the interglacial periods are relatively short between 10,000 and 15,000 years.
To clarify that it was glaciation and ice are two terms that are used interchangeably to refer to two different things but they are related and this creates some confusion. When I say Ice Age I mean a long period of time, tens of millions of years or more, the planet where global temperatures are low enough to support the existence of permanent ice. And I mean glaciation between short periods of thousands of years to hundreds of thousands, usually within an ice age; temperatures are much lower than in the surrounding periods. This distinction is not equal for everyone and especially Anglo-Saxon authors usually the terms are rotated. I should also mention that our current period mild and pleasant climate is unusual that we have been fortunate to enjoy their humanity 140,000 years of existence has only enjoyed this climate about 20,000 years divided into two periods.
So why can we say that we are still in the middle of the ice age? Well the main reason is that the factors that have caused and maintained it, remain enough. The orography plays an important role in local climates, thus the distribution of landmasses on the planet affects the global climate. In the Carboniferous and Cenozoic match in the existence of a continent at the South Pole and the North Pole also in the Carboniferous and almost blocking the general trends in Cenozoic North Pole. The continents at the poles prevent the arrival of ocean currents that carry energy from the equator and it causes the polar snow cover which makes them more reflective that back energy to space; on the other hand if earth has the continents in poles then they aren’t at the equator, and the water is more reflective than the ground, water dominates equator also increasing energy back into space. Orographic changes are very slow and hence the Carboniferous lasted 90 million years and probably similar time will need earth that Antarctica leaves the South Pole. The other argument is to compare the actual temperature with the temperature outside the Carboniferous or Cenozoic, much higher in any latitude where the temperature of the sea water was from 4 to 15 C above current averages (the second is at the poles). The existence above poles of permanent ice indicates that we have not far to the ice age.
Another argument is the fragility of the climate of Western Europe. Just look at the latitude of Lisbon and compare the climate of cities with the same latitude as Seoul and Washington, and northwest Europe coincides with Tasmania and Patagonia. This difference is due to the warm water from the equator and that drives the Thermohaline circulation. The passage of hot water northwards is possible only over the Atlantic Ocean to the Pacific (Bering Strait) is very shallow streams having general circulation. But this hot wedge rises far north and westerly winds drive the heat coming through Europe. This current depends on the salinity of the water, and in this time of rising global temperatures is causing a thaw, which provides fresh water to the ocean surface. If you reduce the surface salinity of the Atlantic Thermohaline circulation not raise both north causing a drop in temperatures in Europe and in turn the entire northern half of the hemisphere continental because ice rising again and that the albedo* triggers the temperatures drop (read feedback where a more complete reasoning).
For the moment though many glaciers have retreated, the salinity of the water has not been affected much. This is because on the one hand that almost all ice of Greenland remains intact, and on the other hand most water melted has gone to the Arctic and it's trapped there. Fresh water trapped in the Arctic and its problems are treated at the finish of the tract North Pole ice can provoke a new ice age whst is a time bomb. Greenland is another bomb. Satellite images taken during the summer showed that mechanical consistency begins to break and if weather continues warming, as expected, this will start to melt quickly. As first case like the other provide large quantities of fresh water into the Atlantic Ocean.
Lastly is global warming. It could be that really be able to reverse the current ice age, but it is unlikely. As well as expose the drop that make the glass overflow, it is likely that global warming is only part of the current climate fluctuation, of course it altered by us. Surely if we had not blurned so many fossil fuels would be beginning of a time similar to that of classical Greece and the early Roman Empire. But considering that we have reached the limit of the short interglacial periods could be just the return to them, which would be a little advanced optimum**. It may seem strange but the end of the last ice age did the same but negative: a warm period almost ended abruptly for a very short cold and also ended abruptly that gives way to the interglacial we live.
* Albedo is the energy balance that reflects a respect for the sun it receives. The Earth is a planet with surface of great albedo because it has lots of water (liquid and solid), increasing the continental ice increases the albedo and therefore more energy is reflected lowering the temperature.
**We understand for optimal to warmer period into interglacial, in our case is ~ 6000-4000 BC in Neolithic
**We understand for optimal to warmer period into interglacial, in our case is ~ 6000-4000 BC in Neolithic
Comentaris
Publica un comentari a l'entrada