BBC NEWS | Business | Climate change fight 'can't wait'

Global Warming Could Cause Mass Extinctions by 2050, Study Says

SPACE, TIME AND GOD

Global Warming

Global Warming Program | Union of Concerned Scientists

here's a thought:

if it's true that due to man made global warming that the polar caps are melting, then wouldn't it also hold true that with all that ice cold water flowing from the North and South polar ice caps and mixing into the warmer waters of our oceans that the average temperature of those oceans would have to drop? if this happens, then would it not be logical to assume that a drop in ocean water temperatures would lessen the likely risk of horrific storms such as hurricanes? after all, these storms do rely on the warmpth of the ocean waters to gain and grow and if these waters are "polar cooled" then it would seem logical that there would be fewer and less intense storms, that is IF the caps are melting due to man made global warming. as well, would it not be logical that if the ocean's temperature is dropping that the earth's overall temperature would eventually drop since such a large part of our earth's surface is made up of these oceans?

.......just wondering..........

I've posted this before, but I still can't find any scientific response to it:

There's a Science article (free subscription required) on Greenland ice core records taken as part of the GRIP bore-hole project:For visual people:

The picture is from an article by Roy Spencer using data from the Science article; the Mann et. al. data was derived from tree rings and similar sources.

That record is supposed to be confirmed by a separate core project, GISP2, but I can't find the data online. If the medieval warming period was actually warmer than present, there's a higher likelihood that we don't have to worry about global warming; if the Earth didn't change significantly under slightly higher temperatures then, there's little reason to think it would today, is there? On the other hand, the climate is an almost unapproachable system because of its complexity.

I've read that the "recent" (within a few thousand years of the present) temperature data from Greenland ice cores are inaccurate, but haven't found any scientific justification for that claim.

__________________
"I have nothing new to teach the world." -Mohandas "Mahatma" Gandhi

Not necessarily. First, even as increased melt water flows into the seas at either end of the globe, these waters are being warmed directly by sunlight and indirectly by warmer land. As the floating ice cover around the poles shrinks (which it is doing at record rates) the darker water absorbs more heat from sunlight. The temperate and tropical seas are also warming. These larger bodies of water have a built in lag time response to climate change, so they will continue warming for decades, if not centuries, even if global temperatures were to level out.

Most people think of global warming as some vague change taking place far from where they live. It rarely is taken personally. I happen to feel a personal connection to this issue. The above is a report of how global warming is directly affecting the lives of Alaska Eskimos living in a remote village on the edge of the Arctic Ocean. I lived in this village back in the 1960s hunting and traveling with village hunters. The people there are real to me. The ones mentioned in the report are the children and grandchildren of friends, some now gone. They are facing a challenge that, like it or not, we all ultimately must share.

Indeed it is!

Turns out it happens, alla time!

Why, even "the US government!!!" agrees. NASA/GISS, after a recalibration of thier recording stations across the nation, that the "hottest ten years since 1880 (when records started being kept) in the continental US fell in the last decade.

Well...maybe. Turns out, that they um...er, neglected, during that recalibration to um, er, take said recalibration into the equation and um, er...adjust for it...the way REAL scientists would.

Nevermind the fact that when that is done (and it has been, now, by others with the same data) only THREE (3) of the "hottest years!!!!" since 1880 have occured in the past decade. The two hottest years on record happened in 1932 and 1921. The four hottest consecutive years between '34-38 (hmmm...I KNEW there was sumptin' to that whole Dust Bowl thingy!) a couple of others in the 70s and one back in 'ought afore the turn of the 20th century...

Hmmm....

For those who, because their religion now has them foaming at the mouth and screaming "Heresy!!!! Heresy!!!! Burn the Heritic!!! Buuuuurrrrrnnnnn hiiiimmmmm!!" and unable to grasp the meaning of this from the text, I'll summarize:

MOST of the hottest years on record for the continental US since 1880 happend (are you GW zealots sitting down, with your 'ludes handy?) prior to the 1970s when, you same zealots inform us (and this part makes sense) "greenhouse gas" emissions skyrocketed.

Now...I'm sorry...but can someone explain how fat American hausfraus driving their fat progeny to McDonald's 8x a day in their Suburbans and H2s caused GW in the early to mid 1930s?


Tokie

And therefore, what?

Because the climate is undergoing one of its very normal, not necessarily predictable, but often recorded (historically and in the geo and dendrochronological records) warming trends, we should do what for these "Eskimos" (hmmm....)?

Stope driving cars? Even though the only reason these "Eskimos" are even there is because at one point oh, 20000 years ago when the planet was undergoing one of its typical, very noramal cooling periods the land-ice bridge between Asia and N. America allowed their ancestors to cross?

Hey, here's an idea: The central Antarctic is experiencing COLDER than normal winters and GREATER than normal precip and icepack. Let's ship them all down THERE!

Tokie

And this has NEVER HAPPPENED BEFORE!!!!!!


Right? So when dinosaurs roamed as far north as the Arctic Sea and lived in Antarctica along with the plant life to support them, they wore snowshoes?

Tokie

there was the triassic, jurassic, cretaceous, then the ice age

Cretaceous

1 Dating
2 Divisions
3 Paleogeography
4 Climate
5 Life
5.1 Plants
5.2 Terrestrial fauna
5.3 Marine fauna
5.4 Extinction
6 See also
7 References
8 Notes
9 External links

The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i.e. from 145.5 ± 4.0 million years ago (Ma)) to the beginning of the Paleocene epoch of the Tertiary Period (about 65.5 ± 0.3 Ma). The longest geological period of the Mesozoic, the Cretaceous constitutes about 80 million years. The end of the Cretaceous defines the boundary between the Mesozoic and Cenozoic eras.

The Cretaceous (from Latin creta meaning 'chalk' [1]) as a separate period was first defined by a Belgian geologist Jean d'Omalius d'Halloy in 1822, using strata in the Paris Basin[2] and named for the extensive beds of chalk (calcium carbonate deposited by the shells of marine invertebrates, principally coccoliths), found in the upper Cretaceous of continental Europe and the British Isles (including the White Cliffs of Dover).

Mesozoic era
Triassic Jurassic Cretaceous


[edit] Dating
As with other older geologic periods, the rock beds that define the Cretaceous are well identified but the exact dates of the period's start and end are uncertain by a few million years. No great extinction or burst of diversity separated the Cretaceous from the Jurassic. However, the end of the period is most sharply defined, being placed at an iridium-rich layer found worldwide that is believed to be associated with the Chicxulub impact crater in Yucatan and the Gulf of Mexico. This layer has been tightly dated at 65.5 Ma. This bolide collision is probably responsible for the major, extensively-studied Cretaceous-Tertiary extinction event.


[edit] Divisions
The Cretaceous is usually separated into Early and Late Cretaceous Epochs. The faunal stages from youngest to oldest are listed below; time is referred to as early or late, and the corresponding rocks are referred to as lower or upper:

Upper/Late Cretaceous
Maastrichtian (70.6 ± 0.6 – 65.8 ± 0.3 Ma)
Campanian (83.5 ± 0.7 – 70.6 ± 0.6 Ma)
Santonian (85.8 ± 0.7 – 83.5 ± 0.7 Ma)
Coniacian (89.3 ± 1.0 – 85.8 ± 0.7 Ma)
Turonian (93.5 ± 0.8 – 89.3 ± 1.0 Ma)
Cenomanian (99.6 ± 0.9 – 93.5 ± 0.8 Ma)

Lower/Early Cretaceous
Albian (112.0 ± 1.0 – 99.6 ± 0.9 Ma)
Aptian (125.0 ± 1.0 – 112.0 ± 1.0 Ma)
Barremian (130.0 ± 1.5 – 125.0 ± 1.0 Ma)
Hauterivian (136.4 ± 2.0 – 130.0 ± 1.5 Ma)
Valanginian (140.2 ± 3.0 – 136.4 ± 2.0 Ma)
Berriasian (145.5 ± 4.0 – 140.2 ± 3.0 Ma)


[edit] Paleogeography
During the Cretaceous, the late Paleozoic - early Mesozoic supercontinent of Pangaea completed its breakup into present day continents, although their positions were substantially different at the time. As the Atlantic Ocean widened, the convergent-margin orogenies that had begun during the Jurassic continued in the North American Cordillera, as the Nevadan orogeny was followed by the Sevier and Laramide orogenies.


Geography of the US in the Late Cretaceous PeriodThough Gondwana was still intact in the beginning of the Cretaceous, Gondwana itself broke up as South America, Antarctica and Australia rifted away from Africa (though India and Madagascar remained attached to each other); thus, the South Atlantic and Indian Oceans were newly formed. Such active rifting lifted great undersea mountain chains along the welts, raising eustatic sea levels worldwide. To the north of Africa the Tethys Sea continued to narrow. Broad shallow seas advanced across central North America (the Western Interior Seaway) and Europe, then receded late in the period, leaving thick marine deposits sandwiched between coal beds. At the peak of the Cretaceous transgression, one-third of Earth's present land area was submerged.[3]

The Cretaceous is justly famous for its chalk; indeed, more chalk formed in the Cretaceous than in any other period in the Phanerozoic.[4] Mid-ocean ridge activity--or rather, the circulation of seawater through the enlarged ridges--enriched the oceans in calcium; this made the oceans more saturated, as well as increased the bioavailability of the element for calcareous nannoplankton.[5] These widespread carbonates and other sedimentary deposits make the Cretaceous rock record especially fine. Famous formations from North America include the rich marine fossils of Kansas's Smoky Hill Chalk Member and the terrestrial fauna of the late Cretaceous Hell Creek Formation. Other important Cretaceous exposures occur in Europe and China. In the area that is now India, massive lava beds called the Deccan Traps were laid down in the very late Cretaceous and early Paleocene.


[edit] Climate
The climate was very warm during the Cretaceous; there was no ice at the poles. Sea level was much higher than today, and large areas of the continental crust were covered with shallow seas; sediment cores show that tropical sea surface temperatures may have been 9-12°C warmer than at present, while deep ocean temperatures were as much as 15-20° C higher than today's.[6],[7] The Tethys Sea connected the tropical oceans east to west, which also helped equalize the global climate. Warm-adapted plant fossils are known from localities as far north as Alaska and Greenland, while dinosaur fossils have been found within 15 degrees of the Cretaceous south pole.[8]

The planet may not have been much warmer on average than it had been during the Triassic or Jurassic periods, but it had a gentler temperature gradient from the equator to the poles; a side effect of this may have been weaker global winds, contributing to less upwelling and more stagnant oceans than today's, evidenced by widespread black shale deposition.[9]


[edit] Life

[edit] Plants
Monkey Puzzle Trees, flowering plants, also known as angiosperms, spread during this period, although they did not become predominant until near the end of the period (Campanian age). Their evolution was aided by the appearance of bees; in fact angiosperms and insects are a good example of coevolution. The first representatives of many modern trees, including figs, planes and magnolias, appeared in the Cretaceous. At the same time, some earlier Mesozoic gymnosperms, like Conifers continued to thrive, although other taxa like Bennettitales died out before the end of the period.


[edit] Terrestrial fauna
On land, mammals were a small and still relatively minor component of the fauna. The fauna was dominated by archosaurian reptiles, especially dinosaurs, which were at their most diverse. Pterosaurs were common in the early and middle Cretaceous, but as the Cretaceous proceeded they faced growing competition from the adaptive radiation of birds, and by the end of the period only two highly specialised families remained.

The Liaoning lagerstätte (Chaomidianzi formation) in China provides a glimpse of life in the Early Cretaceous, where preserved remains of numerous types of small dinosaurs, birds, and mammals have been found. The coelurosaur dinosaurs found there represent types of the group maniraptora, which is transitional between dinosaurs and birds, and are notable for the presence of hair-like feathers.

During the Cretaceous, insects began to diversify, and the oldest known ants, termites and some lepidopterans appeared. Aphids, grasshoppers, and gall wasps appeared. Numerous exceptionally preserved insects have been found in the Lower Cretaceous Siberian lagerstätte of Baissa.


[edit] Marine fauna
In the seas, rays, modern sharks and teleosts became common. Marine reptiles included ichthyosaurs in the early and middle of the Cretaceous, plesiosaurs throughout the entire period, and mosasaurs in the Late Cretaceous.

Baculites, a genus of straight-shelled form of ammonite, flourished in the seas. The Hesperornithiformes were flightless, marine diving birds that swam like grebes. Globotruncanid Foraminifera and echinoderms such as sea urchins and starfish (sea stars) thrived. The first radiation of the diatoms (generally siliceous, rather than calcareous) in the oceans occurred during the Cretaceous; freshwater diatoms did not appear until the Miocene. The Cretaceous was also an important interval in the evolution of bioerosion, the production of borings and scrapings in rocks and shells (Taylor and Wilson, 2003).


[edit] Extinction
Main article: Cretaceous-Tertiary extinction event
In the extinction event that defines the end of the Cretaceous, a significant number of species (~50%) and known families (~25%) disappeared. Plants were nearly unscathed, while marine organisms were hit the hardest. These include a large number (~95%) of types of planktic foraminifers (excepting the Globigerinida), an even larger number of Coccolithophores, all the ammonite and belemnite cephalopods, and all reef-forming rudist molluscs and inoceramid clams), as well as all marine reptiles except turtles and crocodiles. Dinosaurs are the most famous victims of the Cretaceous extinction. Dinosaurs that were unique to the very end of the period (such as Tyrannosaurus rex, Triceratops, and Ankylosaurus) were wiped out. The last of the pterosaurs became extinct and the vast majority of birds did as well, including the Enantiornithes and Hesperornithiformes.

The intensive mid-Cretaceous insect extinction began during the Albian.

The "ice age" is just what it's popularly called, and the last one, ending about 30kyrs BP was just one of many, and not even the worst.

And yes...species are always going extinct. In fact, that's pretty much what's natural for them. Most only last about a million years.
Mass die-offs such as the K-T one and the one that killed the dinosaurs (actually, these are two different events, so I'm not sure where you got your information...but it's not quite accurate) are different animals, not fully understood. However, the natural state of all species is a slow--or sometimes fast--march toward extinction. Something that is also not very well understood, especially since some species--spiders, sharks, planktons and of course microscopic organisms--just seem to take a licking and keep on ticking..for tens and hundreds of millions of years. Of course, with the exception of a few microorganisms, most change over that time...there are not more megaladons cruising the oceans, for example.

The shrieking that we are experiencing a mass die off caused by humans right now, is nonsense. Of course, any time a bunch of dolphis or seal dies off somewhere, the first thing everyone does is run around in circles, waving their hands over their heads and shrieking "how did humans cause this!?"

Animals always managed to die on their own before humans existed and (gasp!) still manage to do it even though we are now the dominant species on the planet. That's not to say (as many in here are now gasping) that humans don't cause extinctions and mass die-offs and even the occasional death of a dozen dolphins or such. Indeed, there is pretty good evidence that prehistoric humans in N/S. America(yes...that would be um...Indians, those good shepards of our Mother, the Earth) killed off the megafauna that used to live here, the mastadons, giant sloths, mammoths, giant bison, etc., precipitating the attendant die-off in other species once these keystone species were all bar-be-qued. It is LIKELY that (here's the tie-in to warming) that they (the Indians) were able to do this due to the fact that these populations (animals) were already stressed by their rapidly warming (from the ice age) ecology and on their way out (extinction event), anyway.

Long and short: climate changes. Often very rapidly. It's now believed "ice ages" end in DECADES not tens of thousands of slow years. When climate changes, some species cannot adapt and they die off.

Before man came along, climate was changing and species were dying off. Yes, we likely impact that (extinctions) now, given our dominance of the landscape, but we have nothing whatever to do with climate change.

Sorry to tell you libs that. We are just too puny. We are not, as you believe, God.

Tokie