Science/Environment The Carbon Debate, pt III

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Good to see The Economist come to the same conclusion as I did on sea level rise :)

And so it would be entirely appropriate if the damage done by Sandy shakes Americans out of complacency on the issue of global warming, despite the relatively tolerable price tag of the storm. The storm is costlier than the estimated bill reflects. And future storms will be costlier still.

Many scientists and journalists are cautious in listing climate change as a causal factor behind a storm like Sandy. Understandably so: weather emerges as part of a complex system, and it would be impossible to say whether a storm would or would not have materialised without global warming. But scientists are becoming ever less shy in drawing a line between a higher frequency of "extreme" weather events and a warming climate. Climate shifts the probability distribution of such events, and so global warming may not have "caused" Sandy, but it makes Sandy-like storms more probable. As the ever-less-funny joke goes, 500-year weather events seem to pop up every one or two years these days. Frequency and intensity of storms aside, future hurricanes that hit the east coast will do so atop rising sea levels. Contemplate the images of seawater rushing over Manhattan streets and into subway and highway tunnels. Then consider that sea levels are rising. And then reflect on the fact that New York is very much like a typical megacity in being located on the water; tracing a finger around America's coastlines leads one past most of the country's largest and richest cities.

http://www.economist.com/blogs/freeexchange/2012/10/hurricane-sandy
 
At one point back in history when the sea levels were higher New York would have always had meters of water in it. Over time things change. How is a category 2 storm a 1 in 500 year storm?
 
At one point back in history when the sea levels were higher New York would have always had meters of water in it.

Yes. For instance, around 15 million years ago when temperatures were 1.5° - 3° C higher and oceans were 20 metres higher, which, not coincidentally, is also the last time CO2 levels were as high as they are today.

Over time things change. How is a category 2 storm a 1 in 500 year storm?

Things don't change by magic, there is always a cause to the effect.

As for '1 in 500', I believe it was in reference the level of precipitation (exacerbated by the warming Atlantic). But the 14 ft storm surge that hit New York was also as statistically unlikely (again, exacerbated by the warming Atlantic, in particular the ft of sea level rise that has occurred around New York over the past century.
 

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I'll give it to you that sea levels are rising at a rate of 3 mm a year. But I don't think that every storm should be labeled as caused by global warming when there have been a lot of worse recorded storms in the last 400 years
 
I'll give it to you that sea levels are rising at a rate of 3 mm a year.

Currently, that rate increases as it warms. And sea levels are nor uniform, weigh regional variability on the range of metres, the NE USA is one region where sea level rise is accelerating well above average, meaning New York is especially vulnerable to storm surges of this kind.



But I don't think that every storm should be labeled as caused by global warming when there have been a lot of worse recorded storms in the last 400 years

No one is saying it was caused by global warming, rather that the magnitude and the destructive impact was exacerbated by global warming. Its exactly the kind of event that we can expect to see occurring more regularly as the system builds heat.

A good analogy is an athlete on steroids, take a baseball player, you can't say for sure that any home run was entirely down to the steroids but you can tell that over time the averages improve because of the steroid use.

In the same way, you might not be able to attribute cause to a single weather event but you can see trends towards more and more intense events.

At the the least one HAS to acknowledge that this is just a taste of what's to come as these kinds of events occur more frequently, the question becomes his many times can you afford to let New York go under water in a century before preventative action starts to look like a valuable investment.
 
how small is the effect though? and how small is human's effect on greenhouse gases? Clouds do most of the greenhouse effect. CO2 has only a very small effect.

And heaps of preventative action is being taken
 
I don't think people realise how much things change at the extreme end when there are changes to the mean. While I don't know that weather events are normally distributed the fact is if the mean changes by a bit what was a 1 in 100 year event could be come a twice in a decade event. Also don't forget heat is just a way of measuring an increase in energy. This increased energy means there is much more violent storms coupled with higher sea levels making things like surges much more damaging.

No one can blame any particular event on climate change. What happens though is a much higher frequency of events occurring that require warmer weather. So things like cyclones or droughts will be much more frequent. That means that we'll see certain higher categories of storm or drought occur more. Though we'll never be able to attribute any particular storm or drought to climate change directly as each event has a non zero probability of occurring without climate change.

Also the combination of inflationary pressures seeing a piece of land numerically represented with a much higher number of dollars, or what ever currency, plus the massive increase in building and infrastructure on low lying coastal areas due to its beauty will see ridiculous numbers being released as "the cost to repair" after a particular storm. For this reason I don't listen to things like "the most expensive storm damage in history" unless the cost was to be compared as fractions of national or statewide GDP.

Upton Sinclair give a good analogy regards the sportsman and steroids to the climate and storms.
 
how small is the effect though? and how small is human's effect on greenhouse gases? Clouds do most of the greenhouse effect. CO2 has only a very small effect.

And heaps of preventative action is being taken

There is so much literature from climate science out there. Upton posts most of the recent work here. Also there is no where near the effort required to reduce output of CO2, which will only be a small part of the work required as we'll need to then look at ways of reducing the amount in the atmosphere.

I think one of the biggest problems people have here is their inability of thinking in timespans beyond their lifetime. It looks like we've raised the world's temperature by a little less than 1deg C in just over a century. Doesn't sound like much, however, in the permian extinction a rise of 5 degrees over 10,000 years lead to 70% of the world's species dying out.

I personally think that the changes we're forcing to the climate wont cause a mass extinction now but may lead to, I think fairly likely, tipping points that cause a big extinction event too, especially hard on the heels of the 40k years of extinction to large herbivores, plus 13k years of extinction of many animals due to farming induced habitat loss. This wont be felt in one person's life span because it will happen over millennia.

Where human's might feel an impact that will be noticed over one lifespan is if climate changes quick enough that farming is impacted and the 7,000,000,000 currently alive and dependent on farming for nutrition struggle to eat. That will lead to "very interesting times".
 
how small is the effect though?

How small? Well, currently
the amount of energy our CO2 is currently causing Earth to anomalously retain is 0.58 watt per square meter. That's about equal to the energy of two Hiroshima atomic bombs every second, 400,000 per day, every day since 1961 and nearly 90% of that is going in to the world's oceans. In other words, not small at all. Quite monumental in fact.

and how small is human's effect on greenhouse gases?

Again, no small at all. To put the scale into perspective, one of the most effective mechanisms that naturally stabilises CO2 levels is through weathering, CO2 reacts with highly silicate rock and get locked in and eventually erodes away. At current rates we'd need 7 cubic kilometres of silicate, ground up very finely and spread in a thin layer across several per cent of the planets surface to absorb just 1 years worth of emissions.

Clouds do most of the greenhouse effect. CO2 has only a very small effect.

Both demonstrably wrong statements. For starters, you're thinking of water vapour, not clouds, which remains constant in the atmosphere because it condenses into rain after a few days and never accumulates. Water vapor levels change when temperature changes, they cant change the temperature. That's really basic physics. At any rate, satellites already measure incoming/outgoing heat energy, not only can we measure the imbalance but we can use spectrography to identify the signature of which gasses are trapping who much heat. Water vapor remains constant but greenhouse gases continue to rise. Its irrefutable.

And heaps of preventative action is being taken

Some. Not heaps. Nowhere near enough to prevent a minimum of 2°C by 2100.
 
http://www.nature.com/nclimate/journal/v2/n6/abs/nclimate1389.html

Physically based assessment of hurricane surge threat under climate change

Ning Lin, Kerry Emanuel, Michael Oppenheimer & Erik Vanmarcke

Nature Climate Change 2, 462–467 (2012) doi:10.1038/nclimate1389
Received 07 September 2011 Accepted 02 January 2012 Published online 14 February 2012

Abstract

Storm surges are responsible for much of the damage and loss of life associated with landfalling hurricanes. Understanding how global warming will affect hurricane surges thus holds great interest. As general circulation models (GCMs) cannot simulate hurricane surges directly, we couple a GCM-driven hurricane model with hydrodynamic models to simulate large numbers of synthetic surge events under projected climates and assess surge threat, as an example, for New York City (NYC). Struck by many intense hurricanes in recorded history and prehistory, NYC is highly vulnerable to storm surges. We show that the change of storm climatology will probably increase the surge risk for NYC; results based on two GCMs show the distribution of surge levels shifting to higher values by a magnitude comparable to the projected sea-level rise (SLR). The combined effects of storm climatology change and a 1 m SLR may cause the present NYC 100-yr surge flooding to occur every 3–20 yr and the present 500-yr flooding to occur every 25–240 yr by the end of the century.[/quote]
 
Yes. For instance, around 15 million years ago when temperatures were 1.5° - 3° C higher and oceans were 20 metres higher, which, not coincidentally, is also the last time CO2 levels were as high as they are today.



Things don't change by magic, there is always a cause to the effect.

Ok then Upton, why did we endure such high levels of CO2 15 million years ago?

Surely this wasn't due to AGW or was it?
 

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Ok then Upton, why did we endure such high levels of CO2 15 million years ago?

Surely this wasn't due to AGW or was it?

The tectonic activity that tore Pangea apart.

Not that its particularly relevant. Whether humans dig it up or it gets released when a continent tears itself apart the consequence is the same and that's what's important.
 
Still seams to me that its just what ever the weather is at the moment its just blamed on climate change. Remember 3 years ago Australia was forever going to be in drought :D .

A "news" report I heard about a year back had an expert who said Australia was going to get hotter, more droughts, more fires it was also going to get more flooding and cold snaps as well as hurricanes up north. Because of Climate change. They just change what climate change is doing depending on the weather in the last few days. After a warm day reporter for channel 9 blamed it on climate change this was the evidence she had "Even today the temperature is 6 degrees above average"

On a Antarctica documentary last year It was said very clearly that the continent was melting. But now that Antarctica is at record levels of ice this is what was predicted to happen :rolleyes:.

The media is very biased
 
Still seams to me that its just what ever the weather is at the moment its just blamed on climate change. Remember 3 years ago Australia was forever going to be in drought :D .

A "news" report I heard about a year back had an expert who said Australia was going to get hotter, more droughts, more fires it was also going to get more flooding and cold snaps as well as hurricanes up north. Because of Climate change. They just change what climate change is doing depending on the weather in the last few days. After a warm day reporter for channel 9 blamed it on climate change this was the evidence she had "Even today the temperature is 6 degrees above average"

On a Antarctica documentary last year It was said very clearly that the continent was melting. But now that Antarctica is at record levels of ice this is what was predicted to happen :rolleyes:.

The media is very biased

Australia will be in drought more often and they will be more severe. We have had La Nina conditions for the last few years, that has over ridden that.

Very intense storms will become more statistically probable. Climate change will not "cause" any of them because that is a weather event, however, warmer oceans have more energy in them and warmer air contains more moisture and more energy so climate change loads the dice.

As the globe heats up initially there will be more ice/snow on Antartica because precipitation is nearly non existent there because of cold. Warmer air means more so thicker ice.
 
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As the globe heats up initially there will be more ice/snow on Antartica because precipitation is nearly non existent there because of cold. Warmer air means more so thicker ice.

I'd add to this that the OP us confusing different issues. He has trouble comprehending the growth in sea ice, while the loss of ice he refers to in continental ice. Its little wonder he finds press releases confusing when he doesn't understand the basics of what are being discussed.

To summarise: sea ice is increasing, ad per the models. West Antarctica is warming faster and losing mass, as pet the models. But east Antarctica, predicted to gain mass by the models has been shown by the GRACE satellite to be losing mass.
 
I also don't think they grasp the times spans we're talking about. Human minds struggle with magnitude and it is why things like evolution is hard to understand. On top of this most people don't seem to understand what a huge difference just a small difference to the mean is when you think about how many actual measurements are taken.
 
I also don't think they grasp the times spans we're talking about. Human minds struggle with magnitude and it is why things like evolution is hard to understand. On top of this most people don't seem to understand what a huge difference just a small difference to the mean is when you think about how many actual measurements are taken.

Indeed. Or the scale of the numbers in question. For instance, the amount of energy required to cause a phase shift of H2O on the surface of the planet is immense. And once that ice is gone its not coming back without a dramatic reversal in tge current energy balance (ie a change on the orbital path of the earth around the sun, a truly epic reversal) The Hiroshima analogy is a good one, the GHG's we've introduced to the system is trapping heat energy equivalent to 400,000 Hiroshima bombs a day every day since 1961.

This article really puts the impact we are having on the planet into perspective. We have become a geological force, with the current geological epoch we have initiated now being dubbed the Anthropocene by geologists

http://theconversation.edu.au/our-e...real-how-were-geo-engineering-the-planet-1544

The rate heat is released from the earth – a measure of its natural “metabolic rate” – is well understood. It’s about 44 trillion watts, and reflects the average rate of energy transferred in moving all the continents, making all the mountains, the earthquakes and the volcanoes on our planet in a process we call plate tectonics.

By way of contrast, the International Energy Agency estimates our human “energy system” operates at a rate of some 16 trillion watts.

So we are already operating at one-third the rate of plate tectonics, and with our energy use doubling every 34 years we are on course to surpass plate tectonics by about 2060.

Climate scientists talk about the climate sensitivity in terms of a “radiative forcing” – an obscure term that accounts for the rate of heat energy gain or loss due to a change in a climate parameter.

The radiative forcing of a doubling of CO₂ is about 1300 trillion watts – or 28 times the energy released by plate tectonics.

And we are well on the way to doubling CO₂. In the past hundred years we have added almost 40%, and warming that can only plausibly be attributed to a greenhouse effect is not only heating the atmosphere, but is also pumping heat into the oceans and the crust at a phenomenal rate.

When my students measure the temperature in boreholes across Australia they invariably see that almost as much heat is now going into the upper 30-50 metres of the Earth’s crust as is trying to get out – a result entirely consistent with the surface temperature rises measured by climate scientists.

Recent measurements suggest the oceans have been heating at 300 trillion watts over the last few decades.

The scale of our energy use is truly mind-boggling. In fact, the sheer size of these numbers makes it difficult for most people to grasp and comprehend their significance; few of us have any useful reference frame for comparison.

A new measure of energy use

To put these numbers into a more human context we need a a new measure for our energy use. The “Hiro” is one. It is the equivalent to the energy released by detonating one Hiroshima “Little Boy” bomb every second. One Hiro equals 60 trillion watts.

In these terms, our human energy system operates at a rate of 0.25 Hiros, or one Hiroshima bomb every four seconds. That is the equivalent of more than eight million Hiroshima bombs going off each year.

And we are on a trajectory towards the one Hiro mark by 2100, equivalent to the energy release of one bomb each year for every five-square kilometre patch of land on the planet.

The ocean heating is at 5 Hiros over the last few decades – the energy equivalent of detonating more than a 150 million Hiroshima bombs in our oceans each year.

And the radiative forcing of the CO2 we have already put in the atmosphere in the last century is a staggering 13 Hiros. The equivalent in energy terms to almost half a billion Hiroshima bombs each year.

The world’s human population has grown so much and so fast – trebling in one century and still rising by more than 70 million a year – that it’s perhaps not surprising that the vast scale of our geological impact is yet to sink in.

But it should not be a surprise because the realisation is not new
 
I'm kind of suprised that no-one has really stated that the actual "heat" going into the environment is an additional factor.
Nearly all forms of energy generation uses heat. Some use cooling towers ( and you see the clouds of vapour coming off them in the pictures that the media present as if its CO2 or some other form of smog ), while many others dump the heat into rivers or the ocean dirctly. I havent sat down and added it up, but surely its there.
 
I'm kind of suprised that no-one has really stated that the actual "heat" going into the environment is an additional factor.
Nearly all forms of energy generation uses heat. Some use cooling towers ( and you see the clouds of vapour coming off them in the pictures that the media present as if its CO2 or some other form of smog ), while many others dump the heat into rivers or the ocean dirctly. I havent sat down and added it up, but surely its there.

The article above does the math. The total sum of human energy (I'm assuming per second) is 16 trillion watts. The radiative forcing from a doubling of CO2 is 1300 trillion watts. Its pretty clear that the actual heat sink effect you postulate pales on significance next to the amount of energy bring trapped by GHG'S.
 
Thanks for that article Upton. What bothers me is how some people don't get that energy flow change and what that does. How the co2 continues to force this new energy flow for centuries into the future and how predicted changes to the bioshpere will cause further changes that will see this climatic event last for milenia.
Upton is there any papers showing an upper limit to carbon absorbtion of the oceans? I read some stuff that said their are signs that point to one, but haven't read any that say there definitely is one and what it may be.
 
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Upton is there any papers showing an upper limit to carbon absorbtion of the oceans? I read some stuff that said their are signs that point to one, but haven't read any that say there definitely is one and what it may be.

Not do much an upper limit but rather a peak at which point our emissions outpace the oceans ability to absorb the stuff. Currently the oceans absorb about 30% of our emissions, as that fraction falls it means more ends up in the atmosphere trapping heat. Not sure if the peak has been quantified but there is evidence to suggest it may already be declining

http://precedings.nature.com/documents/5993/version/1

But then again, cancat posted something a month or two back suggesting that the biosphere overall is absorbing as much a share as it was decades ago (or something to that effect, maybe he could post it again for the purpose of the current discussion? ;)) so I would imagine its still somewhat of an incomplete picture.
 

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Science/Environment The Carbon Debate, pt III

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