[petejh]

TomTom - I don't really know what you or others are trying to articulate when you use terms such as 'by then, it might be too late. It Probably already is' - that's quite a melodramatic phrase. Too late for what? For the entire human race to continue 'we're all goners!'? - in which case I disagree completely. Or just 'too late to stop climate change'. In which case yes, I resigned myself that it's been too late for that since sometime in the 90s. What do you mean, or is it just melodrama?

[Stu Littlefair]

Pete - I think it's a useful exercise to think about positive aspects of climate change. Looked at from that perspective you can argue that climate change is an economic challenge rather than an environmental one. The argument goes that nature will muddle on through somehow, but the big issue will be relocating infrastructure to the parts of the globe which are still habitable.

I reckon that misses two points. The first is that the pace of change may be too rapid for much of nature to cope. The second is the risk of positive feedback leading to a severe rise in temps. By severe I mean more than around three degrees.

There's a great book called "Just six degrees" which looks at the consequences of a global rise in temperature of 2, 3, 4... degrees. The science in the book is pretty sound, and the picture it paints at six degrees really isn't pretty. If things get that far, talking terms of the end of humanity is not at all an exaggeration. Of course we may end up nowhere near that.

[Stu Littlefair]

Sorry - the book is "Six Degrees: Our Future on a Hotter Planet"

[Oldmanmatt]

TomTom - I don't really know what you or others are trying to articulate when you use terms such as 'by then, it might be too late. It Probably already is' - that's quite a melodramatic phrase. Too late for what? For the entire human race to continue 'we're all goners!'? - in which case I disagree completely. Or just 'too late to stop climate change'. In which case yes, I resigned myself that it's been too late for that since sometime in the 90s. What do you mean, or is it just melodrama?

There existed an opportunity to perhaps address this sufficiently to prevent things going beyond a certain tipping point (one which spelt the difference between utter disaster and something much worse); there are indications that we may have left it too late.
That is Melodrama, it is justified Melodrama.
Not much on giving into things, but it probably will get a little hairy within a generation or two.

I expect the species to survive, so generally I agree with Pete. I'm also very optimistic of our ability to adapt through technological advancement (I don't think those self-sufficient Starships are too far off the mark or even that far away).

But it's seriously likely to be a large pile of fetid shit in the short term.

[tomtom]

TomTom - I don't really know what you or others are trying to articulate when you use terms such as 'by then, it might be too late. It Probably already is' - that's quite a melodramatic phrase. Too late for what? For the entire human race to continue 'we're all goners!'? - in which case I disagree completely. Or just 'too late to stop climate change'. In which case yes, I resigned myself that it's been too late for that since sometime in the 90s. What do you mean, or is it just melodrama?

Pete - how could I put it more plainly! No drama - it's what I think. It's already too late to move our climate back to how it was as per pre industrial scenarios. So by the time 'society' wakes up and smells the coffee it almost certainly will be too late!

Too late for us? Humans? Well I imagine (and now I have to imagine rather than use predictions) that even if it's worst case - in the wealthy UK we'll muddle on okish .. But it will fundamentally change how we live our lives - what we can do, where we can go and or standard of living. The wealthier will of course be better off. If we were both living in Bangladesh (where 50-70% of the land will be swallowed up by the sea in the coming years) I would say it's a far bleaker picture. That's just the physical changes.. The real strife will come from the political changes that come from the physical - ie populations forced to move, scarcity of water resources etc.. If you look to history - major environmental changes have triggered collapses in society (Minoans spring to mind..)

[tomtom]

I think WallE might be one of the most perceptive films made recently

[petejh]

TT - right, that's what I assumed you meant. Yeah I agree with all of that, but, sorry to sound like a twat, it isn't new information and hasn't been for a long time now in my mind. I've just taken it as an inevitability, I think since around the late 90s, that ways of life and death are going to continue to change in the coming decades - as they have done for eternity. And for the next x-hundreds of years one of the most important influences in who gets to live and thrive and who suffers and dies will be climate change; climate change that is an inevitability of being human with all our natural drives and the consequences they bring.

Stu - looks like an interesting read, I'll get it and read it on the beach in Turkey the week after next. I hope it's more than 6 degrees warmer there than here..
What's his term of reference btw? - 6 degrees since when?

So how much has the earth warmed up so far then? Seems it's hard to say for sure, but here's some pretty solid info I copy/pasted from a blogger's website (dyor):

'The vital context: a longer-term temperature history

Two decades of cool weather, followed by 15 years of warm weather. Wide swings in temperature; a relatively flat trend since 1998 – 2000. For more about the pause see links to climate research in Section 5.

(a)  From the UAH monthly report, the full record of satellite data (started in 1979). Click to enlarge.


(b)  A different view of the UAH data, by Roy Spencer, principal scientists on the UAH team (at his website).


(c)  The UK Met Office shows a longer-term history

These numbers cannot be properly understood until put in a historical context, as in this graph from page 10 of “The Recent Pause in Global Warming” published by the UK Met Office in July 2013.
'

[Sloper]

I'd be interested to see that plotted against global economic growth (not GDP growth/reduction) but absolute growth.

[Johnny Brown]

I'm not sure what you're trying to illustrate with those graphs. They certainly don't show 'how much the earth has warmed up so far'.

I do think a massive correction is probably a healthy thing in the thousands-of-years context of the long-term evolution of the species.

Taking an objective view, I agree entirely.

But not, obviously, in the 20 - 200 year context of the short-term evolution of John and Jane Doe.

I guess this is what most of us are getting concerned about. Probably in our lifetimes, and certainly in our children's lifetimes, we're going to see some major global upheaval. The UK is a good place to be, but I doubt we will be unaffected, both directly (the thames barrier will need serious upgrades) and indirectly (climate refugees).

[petejh]

I'm not sure what you're trying to illustrate with those graphs. They certainly don't show 'how much the earth has warmed up so far'.

 
That is the data you'll find if you want to discover how much the earth has warmed in the past 100 years. I'm not 'trying to illustrate' anything more than that? Unless you've access to some secret data that no-one else has seen? How much do you think the change is?

Here's another:

'Averaged over all land and ocean surfaces, temperatures warmed roughly 1.53°F (0.85ºC) from 1880 to 2012, according to the Intergovernmental Panel on Climate Change (see page 3 of the IPCC's Climate Change 2013: The Physical Science Basis, Summary for Policymakers'


How about NASA?:




What about University of East Anglia?:
http://www.cru.uea.ac.uk/cru/info/warming/

[Johnny Brown]

Those are better, yes. The first two showed a very short period and the third showed 'rate of change' which is likely to confuse. Personally I think it's more instructive to look at much longer time periods for context.

[Sloper]

The interesting thing with that graph is how it doesn't seem to correlate with growth / use of coal & oil.

[Johnny Brown]

Which graph and in what way does it not correlate?

[petejh]

They don't correlate because all the climate data suggests that, from 1880 until the late 70s, there was an overall negative average value i.e. an overall cooling of the global temperature. Followed by a rapid change to positive values around 1978 until the early noughties.

Large-scale use of coal started in the mid 1800s, oil in the early 1900s.


The change to a relatively rapid warming trend does correlate with the second half of a period of accelerating carbon output from fossil fuel use starting in 1945 and going to present-day. Suggests to me as a layman a period of absorption with no noticeable effect followed by a tipping point.

[Sasquatch]

They don't correlate because all the climate data suggests that, from 1880 until the late 70s, there was an overall negative average value i.e. an overall cooling of the global temperature. Followed by a rapid change to positive values around 1978 until the early noughties.

That wasn't how I read the graph.  It was only negative compared to the overall average from 1880-2012.  The low point on the graph is around 1910, with considerable increase from 1910 to 1940, then a tapering off and substantial growth again from 1970 to 2000. 

[Johnny Brown]

a) it would make more sense to have a graph of cumulative fossil carbon put into the system.
b) in a system as complex as the global climate there isn't going to be a simple linear correlation.
c) am I actually expected to defend the global scientific consensus vs armchair observers here? Correct me if I'm wrong Pete, but the undercurrent to your posts seems to be that the warming problem is perhaps being overstated?

[petejh]

Whatthefuck?

I'll correct you - you're wrong.

I've just copy/pasted a selection of data showing the global scientific consensus haven't I? How have you interpreted me pasting the data on warming trends here as me disagreeing with it?

[Stubbs]

Nice to see coal making a comeback, maybe we will be able to reopen some pits and ship it to China. Surely a benefit?

[petejh]

They don't correlate because all the climate data suggests that, from 1880 until the late 70s, there was an overall negative average value i.e. an overall cooling of the global temperature. Followed by a rapid change to positive values around 1978 until the early noughties.

That wasn't how I read the graph.  It was only negative compared to the overall average from 1880-2012.  The low point on the graph is around 1910, with considerable increase from 1910 to 1940, then a tapering off and substantial growth again from 1970 to 2000.

Agreed, but an increase in itself doesn't mean it was an increase to above-average warming, it's just an increase. I don't think it's misleading to say that the most significant increase in temps occurred in the period 1978-present day and here the picture is clear to anyone.

I think Sloper is picking up on the fact that carbon emissions from fossil fuel started increasing in the mid 1800s - so why not a direct correlation in the temp increase? Time-lag / a tipping point in the atmosphere's ability to absorb carbon would be my guess.

The fact that the temp-change is relative to the 1880-2014 average is interesting. It's a pity we can't see temperature data relative to, say, the average from 2000BC to present day because that's what a lot of skeptics hang their argument on. But whatever, the 100 year figures still paint a pretty stark picture for the last 30 years.

[Oldmanmatt]

Really guys that dip is a well known event!

http://en.m.wikipedia.org/wiki/Krakatoa

The data you are looking at is all way too short period for a clear picture of the rising temps.

http://www.scientificamerican.com/article/global-average-temperatures-are-close-to-11000-year-peak/



The last thousand years.

It's not just the industrial revolution, it's the whole population increase. We burned fuel for heat/cooking in vast amounts before manufacturing much.

Can you see that massive leap at the end?

That correlates with our Industrial revolution/population explosion.

Otherwise, Pete's data is way too skewed by the "Little ice age".

Also, 1914-18 has supposedly had a cooling effect as did 1939-46, due to dust/smoke emissions.

Essentially, worrying about the peaks and troughs or even the 5 year mean is pointless and misleading.

Use a fifty year mean, at least.

Edit..

I actually meant to point out, that there has been a rising trend since 1000ad.

If you projected that trend to "ignore" the little ice age (it was a Icelandic Volcano that started that and lead to mass famine across Europe, can't recall the name. Tom?) then the current temps are way over what you would have predicted and do correlate with the Fossil fuel explosion.
That significant dip, in 1880 and for the following decade, throws out the curves but has a clear reason AND the dip is not as low as it should have been given the size of the eruption. It has been suggested that this correlates with the massive increase in CO2 emissions in the same period.

[tomtom]

Good to see Manns charts.... Much de and re constructed..

The important point from these is not how much it has gone up over the last 1000 years but how rapidly its risen in the last 100... Rates of change not values...

Cause of the LIA is controversial. Volcanic cooling is the new boy in town, Low solar activity the old/established paradigm (we have sunspot observations back to then). The left field idea is that mass reforestation post Black Death reduced Co2 levels and temps. Anyway- look at the temp data for the last 1kA and the LIA is small compared to the last 50!years change... And that led to frost fairs on the Thames, widespread glacial advance and years of bad harvest famine etc.. Across Europe.

[petejh]

I wish my mining stocks looked like that graph.

[Johnny Brown]

Apologies Pete then.

Placing the 0 point at the average of the period is the convention, but as Matt's Mann's graph shows the previous trend was general cooling. The sudden change to warming is clear, and correlates with the industrial revolution. To me it is entirely misleading to state the most significant temperature increase occurred post '78.

[a dense loner]

Re the graph, am I being an idiot? Temperature anomaly on the vertical axis, only goes above 0 in 2 places everything else is minus. How can it be minus for everything else? -4 seems the norm, how come this isn't set as 0 since being normal is not really an anomaly

[petejh]

I didn't fully answer your question JB, about whether I think the warming problem is overstated, becasue my answer isn't a short one and I've written and deleted an essay's worth. In brief: I don't so much frame climate change as a 'problem' that can be solved, as more of an inevitable self-correction to be endured and a catalyst for surviving generations to make necessary changes of outlook/behavior.
Inevitable, because ultimately it's not just a problem of science but a philosophical problem about how we live our life and the paradox of collective over individual action (no individual would choose the likely effects of global warming but no individual is responsible). Warming has been 'treatable' in theory for decades, a bit like drug treatment for Ebola was possible in theory but not acted-on until a large outbreak. It takes a lot of pain to stimulate the sort of change in behavior and thinking required to have an effect on something this big and complex. I don't think individuals feel enough pain yet from climate change, and I can't help but think it's a bit deluded of well-intentioned people to believe good-intentions and theory are going to change something with the inertia of the beliefs and habits of 7 billion people.

Matt and JB - No disagreement here that the average temp is warming. And no disagreement that it's warming with unprecedented speed in recent times and that this generally correlates to the industrial revolution and that carbon is the main cause - I do stick to my argument that the most significant increase has occurred from the late 1970s to present day JB, and I think you're incorrect to think otherwise -  the data's pretty clear and these folk also appear to disagree with you:

http://earthobservatory.nasa.gov/Features/WorldOfChange/decadaltemp.php[/url]]According to an ongoing temperature analysis conducted by scientists at NASA’s Goddard Institute for Space Studies (GISS) and shown in this series of maps, the average global temperature on Earth has increased by about 0.8°Celsius (1.4°Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade.

http://earthobservatory.nasa.gov/Features/WorldOfChange/decadaltemp.php

We're currently at around a .8 degree global average temp increase since 1880 (part of a cooler than average period). That's probably going to continue upwards quickly to around 2 degrees and maybe higher. To me it makes sense to research and anticipate the pro's and con's of a world 2 or 3 degrees warmer, which is likely going to be the future scenario whatever any individual wishes it to be.



Edit: Dense, you're not being an idiot because it's not at all obvious. The answer is in the small print of the research article that the graph comes from: 'the temperature anomalies for all the records are referenced to the 1961–1990 instrumental mean.'

This is common for all temp anomaly graphs you'll see, as I understand it's common to use as a reference either a 30-year period between 1960-90, or a 100 year period between 1900-2000.