Global Warming/Climate Change Discussion Thread

[Mark T]

What massive fluctuation?

es, aerosols (such as soot and dust) contribute to global cooling - hence why volcanoes contribute a net cooling effect (despite the fact that they belch out tonnes of GHG's too)... indeed, the effect aerosols have on climate is one of the major sources of uncertainty in climate modelling...

Sorry I got a bit carried away earlier when I said "massive".

What have been the major causes if climate change in the past?

 

[Keef]

I say let it get warm--like it's supposed to. It's 77 F outside right now and its fabulous. Our normal average high is about 55 this year.

But that happens all the time. With a global average change of just a few degrees, what's the big deal? We humans can adapt, and most of the notable animals out in the wilderness probably wouldn't mind taking naps in the heat either.

 

[BlackedoutRX7LM]

A LOT of people have become very wealthy by spreading global warming propaganda. Props to them

 

[Touring Mars]

What have been the major causes if climate change in the past?

There's a good website here on that topic - although they don't mention a few obvious (albeit incredibly rare) things that would definitely affect the climate for very long periods of time, like a flood basalt eruption, or an asteroid impact.

With a global average change of just a few degrees, what's the big deal? We humans can adapt, and most of the notable animals out in the wilderness probably wouldn't mind taking naps in the heat either.

Animals can adapt, but it is more a question of 'how fast' rather than 'if' they can... there is already evidence linking patterns of species redistribution and adaptation to global warming. Further work on this topic suggests that global warming poses a significant risk to a huge number of species. Clearly, species adaptation and extinction are natural phenomena, but there is growing evidence to support the view that the current warming trend poses an unusually significant risk, since the rate and magnitude of warming is greater than many species can hope to accommodate or adapt to.

 

[Famine]

Animals can adapt

Or can they?

[/Creationist baiting]

 

[Stevisiov]

I am sure batches of perfectly adapted intelligently designed species are just ready to displace the imperfectly designed ones while we aren't looking

 

[homeforsummer]

I have little doubt that human activity is the major culprit in the current warming trend, not just because of what we know about human activity, but also because of the simple lack of a credible alternative explanation.

Great post 👍 I echo your points almost entirely. I'd like to add to this, and to my previous post and vote too, that I am of the opinion that regardless of the the proportional impact humankind has on the Earth compared to anything else (natural stuff like volcanoes and cows farting), it can only be a good thing at least making an effort to reduce our impact.

The Earth may well be going through a natural warming cycle, but is that any good reason to add to it willy-nilly? Even if climate change is something that's happening regardless of our presence, it seems a bit stupid to speed it up.

And on a purely selfish note, which is something that humankind is rather good at already - it's a fairly simple equation. If you use less energy, it costs you less money. If you drive like a twonk all the time and get 10mpg less than the car's quoted, then you have little right to complain about how much you spend on petrol. Likewise, if you have a large family you can only expect to pay more for your energy bills unless you try and use energy more considerately. It'd be a little rich popping out six kids and then moaning about how your bills are expensive, or how the massive car you need costs loads to run.

(Not to worry Homeforsummer, I haven't forgotten about you. You'll get a response.)

Cool, something to look forward to

 

[Danoff]

>
Please, feel free to stick your fingers in your ears and sing "I'm not listening!" some more. I can provide plenty more examples than those above. If I could be bothered, I'd go to my uni library and find a few dozen books citing deforestation as one of the causes of desertification.



Wow. Sarcasm. Bet it took a lot of research to come up with that.

I'm hardly suggesting that removing a few trees is going to result in a desert, but deforestation can result in a desert. Trees, plants, flora in general all hold moisture and nutrients in the ground, they hold nutritional topsoil in place preventing it getting blown/washed/dried away, and their canopies prevent too much sunlight in hot climates getting to the ground and letting it become arid. If ground becomes arid it becomes a much more difficult environment in which to support life, so even if there were trees etc there originally, it then becomes much harder for plantlife to exist there afterwards.

And not just plantlife, but life in general. Animals who call a forest their habitat, and humans who rely on nutritious ground in which to grow crops.

Finally, I'm not suggesting that deforestation is the only cause of desertification - if I was I'd be contradicting many of the quotes I posted above. But we got onto this because you refused to believe that plantlife - trees in particular - effectively prevent places turning into deserts, as Prosthetic mentioned. Which is wrong, plain and simple.



Probably true, though obviously if you have a disproportionate amount of desert then no amount of sand being blown about will help the rainforests. Rainfall is equally important, and much of the rainfall in rainforests is caused by evaporation. And you don't really get evaporation from arid ground, i.e. deserts.

I think we have a different definition of desert. Your link to the wikipedia "Desertification" showed how the removal of trees might result in a temporary reduction in plantlife - but it didn't establish that the place could be classified as a desert as a result of deforestation.

When I see and use the term "desert", I'm referring to a rainfall threshold. That's why I posted this:

...but the reverse is not necessarily true - especially when human are in the mix.

...in reference to the fact that cutting down trees doesn't reduce rainfall.

So when Prosthetic says "trees keep from turning places into deserts", I do not think it's fair to interpret that as "Removing trees from a non-desert region can contribute to an effect known as desertification" - which is what you have done. Interpret it instead as "where there are not trees, the land turns to desert" - which, since trees don't appreciably change annual rainfall numbers in a given region, and since there are many parts of this earth that have no trees but which are not deserts, is indefensibly wrong.

It would be best if we stopped arguing about this and simply agreed that this was a misunderstanding that arose because of loose semantics.

 

[homeforsummer]

I think we have a different definition of desert. Your link to the wikipedia "Desertification" showed how the removal of trees might result in a temporary reduction in plantlife - but it didn't establish that the place could be classified as a desert as a result of deforestation.

My other links were a bit better than the wiki link (the wiki link was just curiosity on my part really, as the concept Prosthetic mentioned sounded familiar to me for some reason), but I suspect you're correct in that we're classing deserts slightly differently.

When I see and use the term "desert", I'm referring to a rainfall threshold. That's why I posted this:

...in reference to the fact that cutting down trees doesn't reduce rainfall.

I've been referring to desert as an area of arid land incapable of supporting more than a few hardy samples of plantlife, which can (and does) occur from human activities including (but not limited to) deforestation (which is something apparent from the different organisations I quoted earlier).

But again, I agree that simply removing trees doesn't reduce rainfall, though if you remove enough trees from an area (such as the Amazon rainforest) weather patterns do change, because dense, moist plantlife is a better environment for evaporation that becomes clouds and eventually causes rain than barren, dry land is. It's why rainforests stay rainy and deserts generally stay dry.

So when Prosthetic says "trees keep from turning places into deserts", I do not think it's fair to interpret that as "Removing trees from a non-desert region can contribute to an effect known as desertification" - which is what you have done. Interpret it instead as "where there are not trees, the land turns to desert"

I'm happy with that. I'd add that certain conditions are contributary though. If enough plantlife (not just trees) was removed from a large enough area that already suffers from things like drought, that area would be very much at risk of desertification. However, if you decided to cut down, say, Sherwood Forest in the UK (of Robin Hood fame), you wouldn't turn the Midlands into a desert because the UK's ecosystem is naturally very damp (to understate the matter a little...) so removing plantlife would be compensated for.

and since there are many parts of this earth that have no trees but which are not deserts, is indefensibly wrong.

But do they have no plantlife whatsoever? This may be something else I didn't make completely clear, but trees are only one example of general plantlife, the removal of which (again in the "right" - or perhaps "wrong" - conditions) can potentially kick-start desertification.

It would be best if we stopped arguing about this and simply agreed that this was a misunderstanding that arose because of loose semantics.

I'm more than happy with that. Though do feel free to comment on any further points I've mentioned above 👍

 

[FoolKiller]

Well, it looks like President Obama and his science advisor have a whole new plan for global warming: Geoengineering. Basically, they want to pump a bunch of other crap into the air to cause global cooling.

http://www.google.com/hostednews/ap/article/ALeqM5hm1kMpA2nQALOfQL8Y8PxxTHNVtgD97ECHLG1

AP Newsbreak: Obama looks at climate engineering
By SETH BORENSTEIN – 1 hour ago

WASHINGTON (AP) — The president's new science adviser said Wednesday that global warming is so dire, the Obama administration is discussing radical technologies to cool Earth's air.

John Holdren told The Associated Press in his first interview since being confirmed last month that the idea of geoengineering the climate is being discussed. One such extreme option includes shooting pollution particles into the upper atmosphere to reflect the sun's rays. Holdren said such an experimental measure would only be used as a last resort.

"It's got to be looked at," he said. "We don't have the luxury of taking any approach off the table."

Holdren outlined several "tipping points" involving global warming that could be fast approaching. Once such milestones are reached, such as complete loss of summer sea ice in the Arctic, it increases chances of "really intolerable consequences," he said.

Twice in a half-hour interview, Holdren compared global warming to being "in a car with bad brakes driving toward a cliff in the fog."

At first, Holdren characterized the potential need to technologically tinker with the climate as just his personal view. However, he went on to say he has raised it in administration discussions.

Holdren, a 65-year-old physicist, is far from alone in taking geoengineering more seriously. The National Academy of Science is making climate tinkering the subject of its first workshop in its new multidiscipline climate challenges program. The British parliament has also discussed the idea.

The American Meteorological Society is crafting a policy statement on geoengineering that says "it is prudent to consider geoengineering's potential, to understand its limits and to avoid rash deployment."

Last week, Princeton scientist Robert Socolow told the National Academy that geoengineering should be an available option in case climate worsens dramatically.

But Holdren noted that shooting particles into the air — making an artificial volcano as one Nobel laureate has suggested — could have grave side effects and would not completely solve all the problems from soaring greenhouse gas emissions. So such actions could not be taken lightly, he said.

Still, "we might get desperate enough to want to use it," he added.

Another geoengineering option he mentioned was the use of so-called artificial trees to suck carbon dioxide — the chief human-caused greenhouse gas — out of the air and store it. At first that seemed prohibitively expensive, but a re-examination of the approach shows it might be less costly, he said.

 

[Tornado]

Its supposed to snow for the rest of this week. In April. And Obama wants to make it cooler?!



[/tongueincheek]

 

[FoolKiller]

Its supposed to snow for the rest of this week. In April. And Obama wants to make it cooler?!



[/tongueincheek]

Sure, you and I have gotten snow, but didn't you hear? The Arctic ice will be completely gone within in a decade.

http://www.telegraph.co.uk/earth/earthnews/5116352/Arctic-will-be-ice-free-within-a-decade.html

Arctic will be ice-free within a decade
The Arctic Ocean could be ice-free in less than a decade, scientists have warned, as the latest figures show the thickness of the ice cap has shrunk to a record low.

By Louise Gray, Environment Correspondent
Last Updated: 11:25AM BST 07 Apr 2009

The Nasa figures showed an increase in winter sea ice this year to 5.85 million square miles, 282,000 square miles above the record low of 2006.

However this is still the fifth lowest on record and 278,000 square miles less than the average extent for 1979 to 2000.

Just ten per cent of the ice is two-years-old or more, compared to an average 30 per cent thicker coverage between 1981 and 2000, meaning the volume of ice is probably lower than it has ever been.

Walt Meier, research scientist at the National Snow and Ice Data Centre at the University of Colorado where the research was carried out, said global warming had caused the ice to retreat dramatically in the last two decades. The six lowest recordings of sea ice cover were all recorded in the last six years.

He said thinner sea ice is less likely to survive the summer and predicted the Arctic Ocean will be effectively ice free sometime between 2020 and 2040, although it is possible it could happen as early as 2013.

 

[Famine]

Wait... there's more by 5% this year, but that means there'll be none in 4 years?

Also, with the first story... You ARE sure you're not a week late with that news story? Please say you are...

 

[FoolKiller]

Wait... there's more by 5% this year, but that means there'll be none in 4 years?

Also, with the first story... You ARE sure you're not a week late with that news story? Please say you are...

Their figures are all over the place with that one. I've seen that story also run with the "90% of Arctic ice will melt this summer" headline.

As for the first story, it was sent to me by a friend who got it off Google news. Follow the link I posted above the quote and it now says 4 hours ago.

If it is older news then Google just picked it up off the AP today.

Or am I missing something else?

 

[Famine]

(a week ago = April 1st)

 

[FoolKiller]

(a week ago = April 1st)

Sadly, no. This is the real brain child of America's new chief scientific advisor.

I knew we were in trouble when this guy is giving us ideas that sound like a take on the Ozone shield (or whatever it was called) in Highlander 2.

 

[Sureboss]

6 million square miles of ice, still sounds a plenty to me.

 

[Touring Mars]

Wait... there's more by 5% this year, but that means there'll be none in 4 years?

Not that ice extent (i.e. area covered in ice) is the whole story... the main message is that the ice is thinner now than it has been since records began, and possibly thinner than it has been for several hundred years.

The increase in ice extent is nothing particularly special, as this graph shows... there is clear variation from year to year, but the trend is downward. Couple this with the downward trend in ice thickness, and the overall message is that the Arctic is losing it's ability to replenish it's ice... the assertion that the Arctic could be ice-free by 2013 should also be tempered by other predictions which put this possibility much farther away, nearer 2040.

Also, with the first story... You ARE sure you're not a week late with that news story? Please say you are...

I don't think it matters which side of the fence your on, this news story rings some mighty alarm bells regardless... it is one thing to acknowledge that man is influencing global climate, it is quite another to presume that man can control it...

 

[FoolKiller]

I don't think it matters which side of the fence your on, this news story rings some mighty alarm bells regardless... it is one thing to acknowledge that man is influencing global climate, it is quite another to presume that man can control it...

This is the Obama administration. They presume nothing, but they do HOPE they can CHANGE it.

 

[Duke]

Sadly, no. This is the real brain child of America's new chief scientific advisor.

I knew we were in trouble when this guy is giving us ideas that sound like a take on the Ozone shield (or whatever it was called) in Highlander 2.

Hey, they've got a firm grasp on all the US economic variables and the consequences of engineering those, right?

So I've got complete faith in their ability to set the global climate right with a few adjustments.

 

[Famine]

Not that ice extent (i.e. area covered in ice) is the whole story... the main message is that the ice is thinner now than it has been since records began, and possibly thinner than it has been for several hundred years.

There doesn't seem to be any data regarding the ice thickness - only that it's "probably" thinner than 2006... But to be honest the numbers are... all over the place.

 

[Danoff]

Temperature goes down... sea ice gets thinner.... wait.

 

[Omnis]

Jesus, I bet the chemtrail conspiracy theorists heads will explode.

I really, really hope Obama and his cabinet don't follow through with their geoengineering delusions.

 

[Touring Mars]

There doesn't seem to be any data regarding the ice thickness - only that it's "probably" thinner than 2006... But to be honest the numbers are... all over the place.

Recent data from NASA and NSIDC have shown that Arctic sea ice is thinning... plus, the downward trend in sea ice coverage is clear enough to me. Granted, predictions as to when we can expect an ice-free Arctic may be all over the place, but the present rate of ice loss generally supports the idea that we can expect an ice-free Arctic in the near future.

Temperature goes down... sea ice gets thinner.... wait.

It is widely acknowledged that thinning of the semi-permanent Arctic sea ice requires a long-term warming trend for it to happen, and that is exactly what has happened, despite the global warming denialists' view that we are now experiencing global cooling - but quite how anyone can buy this is beyond me, given that, according to NASA anyway, 11 of the last 12 years were the warmest since 1860.

 

[Danoff]

http://www.nasa.gov/images/content/324804main_meierfig2_full.jpg
It is widely acknowledged that thinning of the semi-permanent Arctic sea ice requires a long-term warming trend for it to happen, and that is exactly what has happened, despite the global warming denialists' view that we are now experiencing global cooling - but quite how anyone can buy this is beyond me, given that, according to NASA anyway, 11 of the last 12 years were the warmest since 1860.

There's a reason why sea ice was retreating (warming) and is currently advancing (cooling). I wonder if the current lack of sunspots has anything to do with that...

Perhaps Obama should at least hold off on the emergency cooling agenda until we know for sure whether or not we've started the next ice age.

 

[Omnis]

There's a reason why sea ice was retreating (warming) and is currently advancing (cooling). I wonder if the current lack of sunspots has anything to do with that...

Perhaps Obama should at least hold off on the emergency cooling agenda until we know for sure whether or not we've started the next ice age.

So you agree with the sunspot explanation too?

I think something with people like Al Gore is real fishy when they won't even consider other possibilities.

 

[Danoff]

So you agree with the sunspot explanation too?

I think something with people like Al Gore is real fishy when they won't even consider other possibilities.

Seems like an awfully big coincidence if it isn't the cause. I don't think we have as good a handle on the various "forcing functions" as we seem to think.

I attended a talk by one of the frontrunners in climate change science at which he explained that it is not yet known whether clouds have a net positive or negative effect on the average temperature.

...clouds....

...that's about as basic as it gets, and we don't even know the sign. This is not a mature field.

 

[Bram Turismo]

Meh, right now I don't care about the global warming issue. It's the 8th of April and we had snow last night

 

[Touring Mars]

There's a reason why sea ice was retreating (warming) and is currently advancing (cooling)

Very simplistic and misleading argument... it is not "cooling" right now, and Arctic sea ice can hardly be described accurately as "advancing" - the increase in Arctic sea ice extent from 2007 to 2008 is well within the bounds of normal variability, even with the downward long-term trend taken into consideration. The trend towards lower ice coverage (as opposed to the single year increase that you are talking about) as well as a measured reduction in multiyear ice extent is consistent with long-term warming, but totally inconsistent with your global cooling story...

I wonder if the current lack of sunspots has anything to do with that...

Nope... direct satellite measurements over the last 30 years show that the current solar minimum is not resulting in any substantial reduction in radiation reaching us from the Sun than during previous minima...

 

[Danoff]

Very simplistic and misleading argument... it is not "cooling" right now, and Arctic sea ice can hardly be described accurately as "advancing" - the increase in Arctic sea ice extent from 2007 to 2008 is well within the bounds of normal variability, even with the downward long-term trend taken into consideration. The trend towards lower ice coverage (as opposed to the single year increase that you are talking about) as well as a measured reduction in multiyear ice extent is consistent with long-term warming, but totally inconsistent with your global cooling story...

Take a look at the last data point. Cooler temperatures, greater sea ice. Adds up.

Nope... direct satellite measurements over the last 30 years show that the current solar minimum is not resulting in any substantial reduction in radiation reaching us from the Sun than during previous minima...

...and how long did that minima last? I think it makes perfect sense that we'd see cooler temperatures (which we are seeing) during a time of reduced solar flux (which we are experiencing).