An NPR report by Christopher Joyce in the cell phone news reported earlier this week related information about a Smithsonian exhibit's information related to the greatest extinction event known in the history of the earth. The end of the Permian event about 250 million years ago nearly extinguished life on earth and was referred to as the "Great Dying".
Volcanic activity, with probably some help from asteroid impacts, reduced ice cover and made atmospheric pollution increase global temperatures far beyond the state we now have. Cold climate animals could no longer survive in the arctic regions where they may have thrived on the land mass prior to its breakup into the present continental condition.
Surface temperatures and absence of polar ice made the cold water input to the ocean bottom stop, or be very slow to replace the bottom water, but the hot surface water would become hotter and make a thicker layer. Water from polar regions would presumably be warmer and lighter than abyssal water, although colder than water from most of the ocean. That water would have an intermediate density that would replace water of similar density under or in the thermocline. The abyssal depths of some ocean basins away from asteroid impact would probably remain relatively unchanged and give refuge from the "Great Dying" to pogonophorans and other species that would provide life to shallower waters after conditions improve.
The end of Permian extinctions were the worst of the Paleozoic Era and exceed the species deaths of the second worst extinction episode at the end of the Mesozoic Era's Cretaceous Period about 65 million years ago. Pre-Cambrian extinctions may have been more deadly in the two billion years of Pre-Cambrian life, but it is unlikely for much evidence to survive geologic processes.
DEEP SEA PHYSIOLOGY
Reports of high rates of oxygen consumption by microbes deep in abyssal sediments seem to be impossible and require a different explanation, although thermal vents and heat from magma could have some interesting physiological implications of which I am unaware.
The rapid growth of giant tubeworms at thermal vents seems dependent on chemosynthesis by bacteria in special tissue as a source of nutrients; like normal pogonophorans, giant tubeworms lack a functional gut.
The reduction of diffusion in water under great pressure that I have suggested as the explanation for the dramatically slow aging of deep sea organisms would seem to be greatly modified at higher temperatures of thermal vents and presumably deeper sediment warmed by the core of the earth if the reported rates are correct.
The abyssal region remains a refuge under siege from plastic and other pollution that may survive our worst climate-altering assaults if anyone will be around a few million years from now to notice.
Joe Engemann Kalamazoo, Michigan June 8, 2019
Showing posts with label global warming. Show all posts
Showing posts with label global warming. Show all posts
Saturday, June 8, 2019
Friday, September 28, 2018
GLOBAL WARMING
Those of us living in temperate climates have winters and summers that clearly tell us weather can be cyclical, even dependably so when orbits around the sun bring recurring variations. Less certain variations can add to or reduce the annual weather patterns. A book that helped me understand more of how those variations impact our climate was published in 2009. The author is perhaps the best informed climate scientist and deserves getting his message spread.
Storms of My Grandchildren by James Hansen (2009, Bloomberg USA, New York, 303 pages) notes on page xv of the preface that "Global warming does increase the intensity of droughts and heat waves, and thus the area of forest fires. However, because a warmer atmosphere holds more water vapor, global warming must increase the other extreme of the hydrologic cycle--meaning heavier rains, more extreme floods, and more intense storms driven by latent heat, including thunderstorms, tornadoes, and tropical storms."
He had given related testimony to a Senate committee in 1988. His earlier 1981 paper in Science "described likely climate effects of fossil fuel use". And apparently was why "the Department of Energy reversed a decision to fund my research, specifically citing criticism of that paper as being alarmist."
The book makes one realize that money and politics inordinately influenced policy decisions beyond rational levels in the past as they do today. Pages 124-139 added to my understanding of that.
I have had a few recent posts telling some of how the oceans have influenced evolution by their layered structure. Hansen, on page 101, says "If we can measure how much the oceans are warming, we will know not only how much additional global warming is in the pipeline but also how much we must reduce the human-made forcing if we want to stabilize climate."
If you want to know more he has some good suggestions and explanations. The most significant new one to me was the safety and efficiency of fourth generation nuclear energy which could operate safely using up the nuclear waste our first generation nuclear plants have generated (about 6 pages beginning on page 194 of chapter nine).
The solution isn't simple, the causes of global warming interact in sometimes uncertain ways. But knowing about greenhouse gases, volcanic eruptions, fossil fuels, alternative energy sources, the sensitivity of glaciers, coral reefs, low-lying coastal regions, and the oceans might help us come to some partial solutions for saving ourselves and the biological world we depend upon.
Joseph Engemann, Kalamazoo, Michigan September 28, 2018
My thanks to Dr. Charles Heller for the loan of Hansen's book.
Storms of My Grandchildren by James Hansen (2009, Bloomberg USA, New York, 303 pages) notes on page xv of the preface that "Global warming does increase the intensity of droughts and heat waves, and thus the area of forest fires. However, because a warmer atmosphere holds more water vapor, global warming must increase the other extreme of the hydrologic cycle--meaning heavier rains, more extreme floods, and more intense storms driven by latent heat, including thunderstorms, tornadoes, and tropical storms."
He had given related testimony to a Senate committee in 1988. His earlier 1981 paper in Science "described likely climate effects of fossil fuel use". And apparently was why "the Department of Energy reversed a decision to fund my research, specifically citing criticism of that paper as being alarmist."
The book makes one realize that money and politics inordinately influenced policy decisions beyond rational levels in the past as they do today. Pages 124-139 added to my understanding of that.
I have had a few recent posts telling some of how the oceans have influenced evolution by their layered structure. Hansen, on page 101, says "If we can measure how much the oceans are warming, we will know not only how much additional global warming is in the pipeline but also how much we must reduce the human-made forcing if we want to stabilize climate."
If you want to know more he has some good suggestions and explanations. The most significant new one to me was the safety and efficiency of fourth generation nuclear energy which could operate safely using up the nuclear waste our first generation nuclear plants have generated (about 6 pages beginning on page 194 of chapter nine).
The solution isn't simple, the causes of global warming interact in sometimes uncertain ways. But knowing about greenhouse gases, volcanic eruptions, fossil fuels, alternative energy sources, the sensitivity of glaciers, coral reefs, low-lying coastal regions, and the oceans might help us come to some partial solutions for saving ourselves and the biological world we depend upon.
Joseph Engemann, Kalamazoo, Michigan September 28, 2018
My thanks to Dr. Charles Heller for the loan of Hansen's book.
Saturday, April 28, 2018
POLAR ICE
Global Warming
Environmental changes caused by global warming seem to be more widely accepted by most, even those living in area with colder than usual weather caused by shifting oceanic currents and the anomalies of air currents and shifts in polar air masses. A recent increase in melting of shelf ice and discharge of cold water was viewed with alarm as something that might be detrimental to life in the surrounding Southern Ocean.
Krill
The crustaceans known as krill serve as intermediates in the food chain by feeding on algae and then being eaten by others in the food chain; even being directly consumed by the largest whales at the top of the food chain, as well as by fish and others. Some think the biomass of krill is greater than the biomass of any other animal.
Krill have a life cycle of at least two years beginning with eggs released from adults near the surface of water close to the Antarctic ice-covered water. The eggs sink and hatch as they are carried by currents of near freezing sea water north from their point of origin. The eggs hatch and the larvae make their way toward somewhat warmer water near the surface that is moving toward Antarctica replacing and then becoming the cold, northward streaming deeper water. By then, two or more years later, the larvae have grown into adults that lay eggs beginning another generation that repeats the journey north in cold deep water, and back to the southern point of origin.
Ice shelves
The reduction of ice shelves and increasing flows of melt water from the continental margin may cause some reduction in salinity with increase in temperature. Over the centuries marine life may have experienced similar changes and developed the ability to survive such changes. Animals dependent on krill may have to adapt to new locations of krill abundance due their changing environment.
Sea level changes
Shelf ice floating on sea water will not change the level when it melts. If it has built up after resting on the shallow sea bottom it could raise the ocean level. If ground ice interface on land warms and contributes to glacial flow into the sea more rise would result. Since the vast amount of ice in Antarctica is under high elevations of ice it is not likely to be rapidly melted.
Greenland
The general consensus years ago was that the ice cover was immune to major melting. It now seems that it is a real danger, but of much less magnitude than melting Antarctic ice would represent.
Joe Engemann Kalamazoo, Michigan April 28, 2018
Environmental changes caused by global warming seem to be more widely accepted by most, even those living in area with colder than usual weather caused by shifting oceanic currents and the anomalies of air currents and shifts in polar air masses. A recent increase in melting of shelf ice and discharge of cold water was viewed with alarm as something that might be detrimental to life in the surrounding Southern Ocean.
Krill
The crustaceans known as krill serve as intermediates in the food chain by feeding on algae and then being eaten by others in the food chain; even being directly consumed by the largest whales at the top of the food chain, as well as by fish and others. Some think the biomass of krill is greater than the biomass of any other animal.
Krill have a life cycle of at least two years beginning with eggs released from adults near the surface of water close to the Antarctic ice-covered water. The eggs sink and hatch as they are carried by currents of near freezing sea water north from their point of origin. The eggs hatch and the larvae make their way toward somewhat warmer water near the surface that is moving toward Antarctica replacing and then becoming the cold, northward streaming deeper water. By then, two or more years later, the larvae have grown into adults that lay eggs beginning another generation that repeats the journey north in cold deep water, and back to the southern point of origin.
Ice shelves
The reduction of ice shelves and increasing flows of melt water from the continental margin may cause some reduction in salinity with increase in temperature. Over the centuries marine life may have experienced similar changes and developed the ability to survive such changes. Animals dependent on krill may have to adapt to new locations of krill abundance due their changing environment.
Sea level changes
Shelf ice floating on sea water will not change the level when it melts. If it has built up after resting on the shallow sea bottom it could raise the ocean level. If ground ice interface on land warms and contributes to glacial flow into the sea more rise would result. Since the vast amount of ice in Antarctica is under high elevations of ice it is not likely to be rapidly melted.
Greenland
The general consensus years ago was that the ice cover was immune to major melting. It now seems that it is a real danger, but of much less magnitude than melting Antarctic ice would represent.
Joe Engemann Kalamazoo, Michigan April 28, 2018
Saturday, February 14, 2015
SNOW STORM STIMULUS
"The weather outside is frightful"
Is the way an old song in a movie starts. Then it moves on to positive things about a relationship. Well, I just was doing somewhat the same after looking out the window. Snow was coming down in bursts to add to the already significant accumulation. But it was no where near the amount Boston had been experiencing. As long as power doesn't go out the gas furnace will run and keep us reasonably warm. As I lingered over coffee and my last piece of toast, I started musing about the value of a snow storm.
GLACIERS
They were an important part of the way God made the world where we live. The Great Lakes wouldn't exist if enormous glaciers of the not so distant ice ages had not carved them deeper by successive advances from what is now Canada. Where bed rock is visible the scratches of embedded rocks the glaciers picked up show how they did the job of gouging out the lakes efficiently.
The melting glaciers left a large quantity of the load of rocks and sand they were carrying to form a deep layer of glacial till deeply covering places such as southern Michigan. That till was layered in many places by the flow of melting water. So layers of rock, sand, and clay are able to provide an abundant source of ground water that is relatively pure until we pollute it by some of our activities.
Mountain glaciers still exist. Many are getting smaller or even disappearing. The annual snow fall can still replace much of the supply for summer melt to maintain streams and water resources of western states. But it is not as reliable. I understand "Grasshopper Glacier" in Glacier National Park has disappeared. It used to release locusts of no longer existing species, captured in its accumulation in the distant past, from the melting front of the glacier.
A woman working in an Austrian field while snow is still in the Alps
A small glacier on top of the Zugspitze, the tallest mountain in Germany
Although global warming is currently having a considerable affect on the Northern Hemisphere glaciers, those of Antarctica may still be growing or maintaining themselves. Once the continental glaciers of North America melted sufficiently, their elevation was not enough to keep snowfall and temperatures at levels to compensate for summer melting.
GROUND WATER
In Michigan, enough rain falls to replenish the ground water. The soil does a pretty good job of purifying the water of contaminants from simple agricultural and domestic activities. Deep well injection of wastes, fracking, and waste dumps improperly sited and sealed can drain into deep aquifers used for well water supplies without soil being able to effectively oxidize, filter, or somehow remove toxic wastes.
Aquifers can be enormous. One in the United States runs from some distance west of northern Illinois for hundreds of miles to the southwest. But heavy use of well water for irrigation has depleted its store of water at a rate exceeding replacement. A somewhat similar phenomenon is affecting oases in the northern Sahara. There, the lowered water table of the enormous store largely left during the ice ages has caused browning and death of some vegetation around the periphery of oases. And some wells show progressively deeper excavation to reach water.
SEASONS AND EVOLUTION
With or without global warming, the seasons will continue. Short term effects on an annual basis will favor selection for either or both, a north-south oriented seasonal migration, or adaptions for either cooler or warmer conditions. Long term effects are similar, but continuation of the same alternation can result in greater change in a species.
Lighter coloration and chunkier bodies are selected for in colder regions. Greater development of melanin pigment in the skin reduces U-V light penetration, thus the production of vitamin D in the skin is less likely to reach toxic levels in tropical climates. Distribution, types, and amounts of hair, fur, or feathers are simple evolutionary solutions for adapting to light and temperature of local conditions. Migration provides a substitution of behavioral change for physical change needed to adapt to climate.
Speed of climate change may be too great for annual migration or adaptation to prevent extinction. Will polar bears survive if summer ice is eliminated in the Arctic Ocean? I don't know. Did rapid warming reduce appropriate habitat for mastodons and mammoths, or did early human hunters eliminate them? I don't know. Perhaps it was both acting together.
Species can often adapt by migration over longer periods of time to new favorable locations unless too much desert, ocean, or mountain range, or intervening populations of predators, or other unfavorable habitat intervenes. It would have been hard for a mammoth to find a log to float on across the Gulf of Mexico. East-West migrations were successful in making Europe, Asia, and North America share very similar groups of species of plants and animals. A land bridge formed between Russia and Alaska was a major factor. Fresh water along the glacial front in that area probably enabled many genera of fresh-water fish that are now shared reach the opposite continent.
SUMMER THUNDER STORMS
Will I have to wait for confinement by another snow storm now or next year, or will a summer thunder storm that keeps me off the golf course provide an inspirational interlude?
Joe Engemann Kalamazoo, Michigan February 14, 2015
Is the way an old song in a movie starts. Then it moves on to positive things about a relationship. Well, I just was doing somewhat the same after looking out the window. Snow was coming down in bursts to add to the already significant accumulation. But it was no where near the amount Boston had been experiencing. As long as power doesn't go out the gas furnace will run and keep us reasonably warm. As I lingered over coffee and my last piece of toast, I started musing about the value of a snow storm.
GLACIERS
They were an important part of the way God made the world where we live. The Great Lakes wouldn't exist if enormous glaciers of the not so distant ice ages had not carved them deeper by successive advances from what is now Canada. Where bed rock is visible the scratches of embedded rocks the glaciers picked up show how they did the job of gouging out the lakes efficiently.
The melting glaciers left a large quantity of the load of rocks and sand they were carrying to form a deep layer of glacial till deeply covering places such as southern Michigan. That till was layered in many places by the flow of melting water. So layers of rock, sand, and clay are able to provide an abundant source of ground water that is relatively pure until we pollute it by some of our activities.
Mountain glaciers still exist. Many are getting smaller or even disappearing. The annual snow fall can still replace much of the supply for summer melt to maintain streams and water resources of western states. But it is not as reliable. I understand "Grasshopper Glacier" in Glacier National Park has disappeared. It used to release locusts of no longer existing species, captured in its accumulation in the distant past, from the melting front of the glacier.
A small glacier on top of the Zugspitze, the tallest mountain in Germany
Although global warming is currently having a considerable affect on the Northern Hemisphere glaciers, those of Antarctica may still be growing or maintaining themselves. Once the continental glaciers of North America melted sufficiently, their elevation was not enough to keep snowfall and temperatures at levels to compensate for summer melting.
GROUND WATER
In Michigan, enough rain falls to replenish the ground water. The soil does a pretty good job of purifying the water of contaminants from simple agricultural and domestic activities. Deep well injection of wastes, fracking, and waste dumps improperly sited and sealed can drain into deep aquifers used for well water supplies without soil being able to effectively oxidize, filter, or somehow remove toxic wastes.
Aquifers can be enormous. One in the United States runs from some distance west of northern Illinois for hundreds of miles to the southwest. But heavy use of well water for irrigation has depleted its store of water at a rate exceeding replacement. A somewhat similar phenomenon is affecting oases in the northern Sahara. There, the lowered water table of the enormous store largely left during the ice ages has caused browning and death of some vegetation around the periphery of oases. And some wells show progressively deeper excavation to reach water.
SEASONS AND EVOLUTION
With or without global warming, the seasons will continue. Short term effects on an annual basis will favor selection for either or both, a north-south oriented seasonal migration, or adaptions for either cooler or warmer conditions. Long term effects are similar, but continuation of the same alternation can result in greater change in a species.
Lighter coloration and chunkier bodies are selected for in colder regions. Greater development of melanin pigment in the skin reduces U-V light penetration, thus the production of vitamin D in the skin is less likely to reach toxic levels in tropical climates. Distribution, types, and amounts of hair, fur, or feathers are simple evolutionary solutions for adapting to light and temperature of local conditions. Migration provides a substitution of behavioral change for physical change needed to adapt to climate.
Speed of climate change may be too great for annual migration or adaptation to prevent extinction. Will polar bears survive if summer ice is eliminated in the Arctic Ocean? I don't know. Did rapid warming reduce appropriate habitat for mastodons and mammoths, or did early human hunters eliminate them? I don't know. Perhaps it was both acting together.
Species can often adapt by migration over longer periods of time to new favorable locations unless too much desert, ocean, or mountain range, or intervening populations of predators, or other unfavorable habitat intervenes. It would have been hard for a mammoth to find a log to float on across the Gulf of Mexico. East-West migrations were successful in making Europe, Asia, and North America share very similar groups of species of plants and animals. A land bridge formed between Russia and Alaska was a major factor. Fresh water along the glacial front in that area probably enabled many genera of fresh-water fish that are now shared reach the opposite continent.
SUMMER THUNDER STORMS
Will I have to wait for confinement by another snow storm now or next year, or will a summer thunder storm that keeps me off the golf course provide an inspirational interlude?
Joe Engemann Kalamazoo, Michigan February 14, 2015
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