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Post by huon on May 10, 2022 10:03:23 GMT 9.5
DBB - "Half" seems excessive. The article does say that 48% of global bird species are likely in decline, but doesn't state that the total number of birds globally has dropped by half.
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Post by huon on May 12, 2022 10:36:27 GMT 9.5
On the other hand, this earlier post by DBB indicates global bird populations have declined by well over 50%. So my questioning of "half" was likely misplaced. In any event, both articles describe the losses as "staggering", and call for effective action to stem the decline.
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Post by Killian on May 19, 2022 12:53:29 GMT 9.5
On the other hand, this earlier post by DBB indicates global bird populations have declined by well over 50%. So my questioning of "half" was likely misplaced. In any event, both articles describe the losses as "staggering", and call for effective action to stem the decline. And bear in mind the moving goal posts. These numbers are being counted from a time when populations were already *much* lower than before industrialization. It's extremely misleading. We need more scholarship to include the short-term losses and the true reductions from pre-industrial times, i.e., pre-1750.
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Post by Roger Clifton on May 20, 2022 10:44:03 GMT 9.5
... bear in mind the moving goal posts. These numbers are being counted from a time when populations were already *much* lower than before industrialization. The progressive loss of habitat does imply a corresponding loss of places where this or that species is recorded, with a corresponding decrease in populations. But a decrease in numbers of individuals does not necessarily imply a decrease in the number of extant species. A planet dotted with nature reserves may be enough to preserve the ecologies for a distant future. However this argument only applies if the range of each animal is much less than the size of the remaining habitats. Thus we may lose the big cats to extinction long before their smaller prey vanishes from the record. In that case, let's hope that one day the larger species can be recovered from bottled specimens to repopulate nature reserves as they die out locally.
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Post by David B. Benson on May 29, 2022 12:31:56 GMT 9.5
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Post by David B. Benson on Jul 1, 2022 3:05:48 GMT 9.5
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Post by Roger Clifton on Jul 3, 2022 15:51:44 GMT 9.5
Atmospheric CO2 is not temporary, it is PERMANENT. We should not tolerate anyone suggesting that it might be possible to emit CO2 now and vanish it later. Apologists might say the article is only being hypothetical, hoping what if it is magically possible to reduce temperatures later? However science has spoken – it is not possible. Moreover the article repeatedly speaks of falling temperatures as though the audience prayerfully wants to believe that temperatures will fall! By innuendo, the author and his willing audience are holding faith that Nature will eventually recover all the while that we continue to wound it. They can raise a thousand prayer wheels to the heavens and 10,000 holy panels onto the roofs of the pious, but most of the energy will continue to be generated by fossil fuels. Chanting off fantasies of Nature recovering will not protect them from the judgement of the future. Check the graph of temperatures rising and (fictitiously) falling. It is conventional to fit a wiggly light-coloured line through noisy but real measurements, then fit a bold line smoothly through it. At first glance the graph shows that scientists have been collecting the truth all the way up beyond 2100, and that the average temperature smoothly and reassuringly retreats back down towards the temperatures our ecologies evolved in. It takes a moment's scepticism to realise that there are no such measurements taken from the future! This is not hypothetical. The graph has been designed to deceive. We should call out on any such charlatanism. We want the world to face up to the fact that today's emissions are killing people and wildlife today, then will continue killing descendants beyond tomorrow. Emitters and their apologists should make no excuse. By acting in full knowledge that their actions are killing people, they are party to murder.
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Post by David B. Benson on Jul 5, 2022 13:29:32 GMT 9.5
Roger Clifton — Indeed, it is well established that if we stop emitting excess carbon dioxide into the atmosphere the global temperature will start to fall. For a popular account, read “The Long Thaw” by climatologist David Archer. The reason is clear; the world ocean’s carbon dioxide isd far from equilibrium with the atmosphere. Less carbonated water arises from the depths and after cooling, sinks again carrying more carbon dioxide and not the reappear for hundreds of years.
The point of the cited article that you took such umbrage to was to point out that even if we go over the 2 *C threshold for just a short time that will already cause irremediable damage.
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Post by Roger Clifton on Jul 7, 2022 20:10:38 GMT 9.5
Less carbonated water arises from the depths and after cooling, sinks again carrying more carbon dioxide and not the reappear for hundreds of years. Not quite. Most of the ocean is capped by a warm layer 100 to 200 m thick. This is the layer in equilibrium with the atmosphere – oxygen, CO2 and heat. This is where about half of anthropogenic CO2 has entered the ocean. It is the layer containing most life in the ocean including the world's fisheries and also the zooplankton that descend through the layer at night and excrete organic carbon into the layer below. Consequently when this colder water does break through the warm layer, it emits CO2. The most famous such upwelling is La Niña off Peru. A pathway that does take water at atmospheric CO2 pressures directly into the depths, is the freeze water from polynyas in the Arctic and Antarctic. It would seem that this pathway will reduce as global warming reduces formation of winter ice. The most powerful upwelling is driven by the roaring forties/fifties around the Antarctic, where the warm layer is absent. The Coriolis component of the wind-driven westerly current lifts the organic-laden layer upwards and northwards. To a lesser extent the deeper (low CO2) layers below get mixed in. Up until recently the net CO2 emissions from the northbound currents were significant, but now the backpressure from the emissions-laden atmosphere is reducing the release. The cycle time for the deepest layers has been considered to be a thousand years, but with global change increasing the westerly winds, that cycle time may become as low as 300 years. The net effect is to draw down CO2 into the depths, but the rate has obviously been slower than the rate we have been emitting carbon since somewhere in the 1800s. While there is a nation anywhere on the earth still emitting CO2 at the rate of the 1800s or more, the drawdown will continue to be overwhelmed. Realistically speaking, there will be no resulting atmospheric diminution in the foreseeable future. The idea of a "temporary overshoot" is wishful thinking. Neither should science-respecting people of conscience indulge any permission to emit CO2 on the basis that the ocean will absorb it.
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Post by David B. Benson on Jul 8, 2022 6:48:16 GMT 9.5
Roger Clifton — There have been temperature pulses in Terra’s geologic history, notably en.wikipedia.org/wiki/Paleocene–Eocene_Thermal_MaximumThe point, once again, is that even a brief excursion above 2 *C over preindustrial temperatures would contribute disproportionally to the sixth mass extinction currently in progress.
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Post by Roger Clifton on Jul 8, 2022 11:45:58 GMT 9.5
a brief excursion above 2°C ... extinction The point is a given. Sixteen years ago, the starting point for the BNC website was that the old climate was gone, each step in the decay an acceleration on the extinction underway. Denial was forbidden. The replacement of fossil fuels with nuclear energy was a necessity. We had the opportunity to design a Brave New Climate. Yet denial persists on BNC. We are supposed to be an island of scientific rectitude in a sea of wilful ignorance. We should not be re-posting clickbait that reinforces superstitious beliefs that global warming can be temporary, and all we need do is make token "reductions", such as putting windmills on hilltops or buying magic batteries, to resurrect the gone climate.
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Post by David B. Benson on Jul 8, 2022 13:58:07 GMT 9.5
Roger Clifton — Global warming will indeed be temporary, ending after the amount of excess carbon dioxide added falls below the ability of removal methods such as weathering. What is now gone forever are the species extirpated. This will grow worse with additional global warming, even if that additional warming is only for brief time. So the Brave New Climate becomes even a simpler environment caused by excess temperature excursions, according to the cited research. That is a result worthy of being linked here, via Phys.org.
Do you actually doubt it?
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Post by Roger Clifton on Jul 9, 2022 11:53:03 GMT 9.5
David is quite correct in saying that ultimately it will be the weathering of rock that brings the level of atmospheric CO2 down towards (and possibly past) the preindustrial concentration. The process is very slow, acting across a timescale of a million years or so. The fact that this is likely to exceed the lifetime of our species is lost on the popular chatter that desperately wants to believe that Nature will remove our continuing emissions in our children's lifetimes.
Those of us who know the hard fact are needed to puncture the popular delusion. We need to repeatedly say to them, "That CO2 is up there for good!"
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Post by David B. Benson on Jul 9, 2022 12:57:26 GMT 9.5
No, Roger Clifton. Climatologist David Archer in “The Long Τhaw” indicates 100 thousand years, not 1000s of thousands.
However, this might be shortened if we are serious about removing excess carbon dioxide more rapidly than just natural weathering. Altermatives are the subject of other threads here on the Brave New Climate Discussion Forum.
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Post by Roger Clifton on Jul 9, 2022 16:09:15 GMT 9.5
removing excess carbon dioxide ... alternatives are the subject of other threads here on the Brave New Climate Discussion Forum. … where they have been thoroughly debunked (check it out!). Removing two thousand billion tonnes of CO2 – that's 1,000,000 km³ of STP gas – would be hopelessly impractical. Even if it were possible, there is just nowhere to bury the capture. We must be truculent with any loony proposal that might be used as an excuse for adding further emissions to the greenhouse. Tell them – "It's up there for good!"
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Post by huon on Sept 26, 2022 12:57:32 GMT 9.5
What killed dinosaurs and other life on Earth? Harini Barath, Dartmouth College 12 Sep 2022 ScienceDaily www.sciencedaily.com/releases/2022/09/220912152923.htmMassive volcanic eruptions, and the attendant release of CO2, appear to be the main cause. Warning signs for today.
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Post by David B. Benson on Sept 29, 2022 2:28:57 GMT 9.5
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Post by huon on Oct 23, 2022 12:20:51 GMT 9.5
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Post by David B. Benson on Nov 21, 2022 7:26:32 GMT 9.5
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Post by David B. Benson on Dec 18, 2022 4:31:43 GMT 9.5
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Post by David B. Benson on Jan 11, 2023 9:10:56 GMT 9.5
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Post by David B. Benson on Jan 22, 2023 4:58:41 GMT 9.5
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Post by David B. Benson on Jan 24, 2023 6:18:03 GMT 9.5
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Post by David B. Benson on Apr 11, 2023 5:39:49 GMT 9.5
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Post by David B. Benson on May 25, 2023 6:55:48 GMT 9.5
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Post by David B. Benson on Aug 8, 2023 5:55:28 GMT 9.5
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Post by David B. Benson on Aug 25, 2023 3:50:56 GMT 9.5
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Post by David B. Benson on Aug 29, 2023 6:11:21 GMT 9.5
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Post by David B. Benson on Sept 17, 2023 3:18:05 GMT 9.5
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Post by David B. Benson on Sept 19, 2023 11:57:37 GMT 9.5
Study finds human-driven mass extinction is eliminating entire branches of the tree of life 2023 Sep 18 Phys.org (Link unavailable just now)
Entire genera, which evolution won’t fill in for millions of years.
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