[Closed] Global warming update!

Interesting question Mike but how can anyone disagree with "all the scientists" when they continue to disagree among themselves?

Zokes, as an aside it was interesting that you have drawn on the Ganges river basin and the concept of MDCs helping LDCs leapfrog certain aspects of the development phase. I would argue that the evidence on this is mixed at best. I have just been supervising GCSE geography revision (sadly a dangerous place to reject force fed ideas about GW!) and sustainable farming systems including subsistence rice farming along the Ganges. So nature (edit and other factors) provides a sustainable farming system, albeit only a subsistence one. MDCs try to impose the "Green revolution" and high yield variants across much of the LDC world. Fortunately lessons were learned about the failures here in the rest of Asia and the Ganges area has rejected many of these so-called advances and maintained a more sustainable farming system. And geography students get to learn all about "appropriate technology" (2 marks) !!

Interesting question Mike but how can anyone disagree with "all the scientists" when they continue to disagree among themselves?

I think it's fair to say that there's an overwhelming consensus among climate scientists that the average global temperature is rising and that the causes of this are man-made. There may be some scientists who disagree, but they're in the minority. On specifics, the climate scientists might disagree but not on the overall picture.

The latest Met Office release indicates that cooling natural forces are countering warming man made ones

So since the Met Office didn't understand these natural forces which have buggered up their forecasts could it be other natural warming forces which accounted for some of the warming in the 1980s and 1990s. After all the temp rise in the first half of the twentieth century was greater than the temp rise in the second half despite manmade CO2 emissions being far less.

Likewise the temps didn't rise over 40 years from 1940 - 1980 despite rising CO2 emissions.

While man's CO2 will affect the climate perhaps the models are wrong in the amount of forcing they attribute to it compared to natural variations.

http://www.cru.uea.ac.uk/cru/info/warming/

teamhurtmore

the "disagreements" amongst scientists tend not to be about the fundamental big picture stuff, but tweaks at the edges....often these "disagreements" are nothing more than revisions by one group of anothers figures in the result of more evidence, datasets, research etc. It's quite wring to categorise this sort of stuff as disagreements...there's good examples of this process going on now with ice sheet melting rates and sea level rise. The state of knowledge of ice sheet dynamics when the last IPCC report was done was very limited, everyone knew that, so the assumptions they made about it and the subsequent resultant sea level rise over the coming 100 years was cautious and couched with terms like "low confidence". In the interveneing 4 years loads of different groups have been studying intensively some quite different aspects of Ice sheet dynamics, that waork is now finding itself into tightly coupled air/ocean/cryosphere models, and numbers for sea level rise are now being generated which look a bit different to the numbers in the IPCC report from 2007, and confidence about their validity is aslos becoming quite a bit higher

Is this a "disagreement"...on one level yes, but the people who did the assessments from pre 2007 will quite happily accept the more current work, but their origial papers are still out there, and will no doubt be misquoted by the usual crowd in an attempt to generate confusion, or mislead the great and the good into thinking the latest work is controversial and untrustworthy

It's frankly a bit of a shocker to see someone who is a geography teacher who thinks the evidence is mixed, I'd suggest you just haven't understood the science and you should rewind back to first principles a bit.

People who tend to study it for a living tend to disagree with you.

Zokes, as an aside it was interesting that you have drawn on the Ganges river basin and the concept of MDCs helping LDCs leapfrog certain aspects of the development phase. I would argue that the evidence on this is mixed at best. I have just been supervising GCSE geography revision (sadly a dangerous place to reject force fed ideas about GW!) and sustainable farming systems including subsistence rice farming along the Ganges. So nature (edit and other factors) provides a sustainable farming system, albeit only a subsistence one. MDCs try to impose the "Green revolution" and high yield variants across much of the LDC world. Fortunately lessons were learned about the failures here in the rest of Asia and the Ganges area has rejected many of these so-called advances and maintained a more sustainable farming system. And geography students get to learn all about "appropriate technology" (2 marks) !!

Given that I work in something called the Sustainable Agriculture Flagship, you're preaching to the converted here! What I was mainly talking about was LDCs skipping the profusely burning oil and coal part of development. One things for sure: we don't need to grow more food, we just need to do much better at managing what food we do grow. I think gwaelod covered the rest

I would agree that there are significant attempts to generate confusion and mightily relieved to note that confidence is "quite a bit higher". Perhaps in time that will be high in absolute terms rather than relative!

No need worry about the teaching bit - I was merely supervising 😉 Have no fear the candidates know what is best for them, and they will regurgitate the force fed ideas. In much the same way I was forced to do as a geography student albeit in those days we had to describe global cooling rather than warming.

Zokes - yes, my comments were an aside. It was the posting of the Ganges map that was just a co-incidence with what I was doing. That must be very interesting work. In the past I was involved (largely indirectly) with the application of mobile telephony to the provision of banking services in Africa. Happily that was a more positive case study but not without it's own hiccups!!!!

No need worry about the teaching bit - I was merely supervising Have no fear the candidates know what is best for them, and they will regurgitate the force fed ideas. In much the same way I was forced to do as a geography student albeit in those days we had to describe global cooling rather than warming.

Actually, I'll revise my earlier statement to mike. It's clear you are merely a denier, as opposed to a sceptic after all

No you were correct first time!

irc could you draw a line of best fit through your data and let me know what temperature was doing during the period you are discussing

[img] [/img]

Most data sets include land , air and sea temperature as well

Does Vostok Ice core data have any relevance today? It looks like a clear pattern over history even though this data is quite dated. I'm quite ignorant of the issue TBH so be gentle 😳

[img] [/img]

it relevant in the sense that it shows us [ whihc no one disputes] that temperature has changed over time [ the forcing effect is the sun generally [ see below] and this is then made worse by the rise in C02 levels.

When the Earth comes out of an ice age, the warming is not initiated by CO2 but by changes in the Earth's orbit. The warming causes the oceans to release CO2. The CO2 amplifies the warming and mixes through the atmosphere, spreading warming throughout the planet. So CO2 causes warming AND rising temperature causes CO2 rise. Overall, about 90% of the global warming occurs after the CO2 increase.

and the two graphs together
[img] [/img]

*[url= http://en.wikipedia.org/wiki/Milankovitch_cycles ]Milankovitch cycles CLICKY[/url]

basically the earth orientates towards the sun as it "wobbles on it axis" and warms and cools over large periods of time due to this - we should be cooling now for example. No one disputes that natural climate change occurs the issue is whether the current change is natural or man made.

Good source of info and debunking of the myths about it from link below - it does "believe" in man made changes - plenty of poor science out there if you want a sceptics site but there is not one I could rate

http://www.skepticalscience.com/argument.php

JY - you are correct to highlight that website, which I have used before. Its a great of example of the excellent [u]and the[/u] annoying. The very first section typifies the current debate. It starts with the categorical statement that "Climate reacts to whatever forces it to change at the time; [b]humans are now the dominant forcing[/b]." We then get a lot of very interesting analysis including the (widely accepted 😉 ) view that CO2 levels amplify temperature changes. Sadly, little specifics on just how much of this is man-made but, no fear, we reach the equally categorical conclusion that, 'it tells us that climate is highly sensitive to the greenhouse warming [b]we're now causing[/b]."

Enough said!

Sadly, little specifics on just how much of this is man-made

Manmade CO2 emissions are much smaller than natural emissions. Consumption of vegetation by animals & microbes accounts for about 220 gigatonnes of CO2 per year. Respiration by vegetation emits around 220 gigatonnes. The ocean releases about 332 gigatonnes. In contrast, when you combine the effect of fossil fuel burning and changes in land use, human CO2 emissions are only around 29 gigatonnes per year. However, natural CO2 emissions (from the ocean and vegetation) are balanced by natural absorptions (again by the ocean and vegetation). Land plants absorb about 450 gigatonnes of CO2 per year and the ocean absorbs about 338 gigatonnes. This keeps atmospheric CO2 levels in rough balance. Human CO2 emissions upsets the natural balance.

[img] [/img]
http://www.skepticalscience.com/global-warming-natural-cycle.htm

This wouldn't make sense either, not only because scientists keep track of volcanic and oceanic emissions of CO2 and know that they are small compared to anthropogenic emissions, but also because CO2 from fossil fuels has its own fingerprints. Its isotopic signature is depleted in the carbon-13 isotope, which explains why the atmospheric ratio of carbon-12 to carbon-13 has been going up as anthropogenic carbon dioxide goes up. Additionally, atmospheric oxygen (O2) is decreasing at the same rate that CO2 is increasing, because oxygen is consumed when fossil fuels combust.

The burning of fossil fuels and changes in land use results in the emission into the atmosphere of approximately 30 billion tonnes of carbon dioxide per year worldwide, according to the EIA.

Fossil fuel emissions rose steadily in recent decades, contributing 8.7 ± 0.5 gigatonnes of carbon in 2008. This is 41% greater than fossil fuel emissions in 1990. CO2 emissions from land use was estimated at 1.2 ± 0.4 gigatonnes of carbon in 2008. Note the proportionally higher uncertainty compared to fossil fuel emissions.

If you are still in doubt [url= http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-3.html#2-3-1 ]THIS LINKY[/url] gives actual measures, sources, references and rationale. like I said no one can possibly doubt that man is creating c02 its preposterous to suggest otherwise.
To summarise we are responsible for th increase the cycle can cope with the natural stuff and is absorbing about 45 % iirc of our emissions

In short all the C02 increase is down to us pretty much

Didn't the Greenland Ice core data have readings as high as that of Mauna Loa before the timeline in the graph above? (a million graphs on this topic on the web, a bleeding nightmare to find out which ones are considered acceptable.)

I'm not skeptical as such just a bit ignorant of all the issues and would like to understand more, (sorry to waste the time of those that already understand.)
I will do a bit more research on some of the facts and figures quoted in the thread.
Interesting debate.

Didn't the Greenland Ice core data have readings as high as that of Mauna Loa before the timeline in the graph above?

No one is saying that temperature and C02 levels would remain constant if mankind was extinct they would continue to naturally fluctuate.
The debate is about whether we are creating C)2 and whether this is causing any warming.
Its hardly difficult to work out that human activity is producing C02 - if there is debate [ its largely from non scientists of the right wing persuasion] it is about what this will do to temperature even though everyone accepts its a greenhouse gas. Very few now argue temperature is not rising though they used to.

One figure that amazed me when I was researching some stuff at uni was that until c.1955-1960, the biggest anthropogenic source of GHGs was from simply ploughing fields.

As has been alluded to, one of the main issues is threshold events and feedback loops such as loosing albedo from snow/glaciers, ocean acidification, methane release from submarine sediments (potentially cataclysmic if sudden), Antarctic terrestrial ice melting etc etc.

Add to that the fact that places like the Gangees delta, East Anglia etc will be rather Atlantis-like in <100 years and it's not something that we can simply ignore really.

Www.chasingice.co.uk I went to see this last night. It's touring round the uk at the moment.

Very beautiful photography and all the evidence you will need that climate change is happening and we have accelerated it at a pace never before seen to occur naturally.

One figure that amazed me when I was researching some stuff at uni was that until c.1955-1960, the biggest anthropogenic source of GHGs was from simply ploughing fields.

I doubt that, but you're in the right industry...

Try methane from rice paddies

Surprised at the rabidness of the greenies - seems to stem from a heightened sense of self importance

The end is nigh, the end is nigh.
yes it is, global warming (if it is happening..) could bring that on quicker but equally something else could **** us up so try and enjoy it while it lasts eh?

Get on with enjoying your life, be sensible and relax a little and you'll probably live longer.
I fear more for a future where militant Eco warriors dictate how many kids we can have or how often we can plow our rice paddies.

Obvious troll is terribly obvious

Not trolling these are my beliefs.

Excellent - please take a walk to the middle of Afghanistan and start writing some graffiti about prophets. Take a video camera too so it will give us all a giggle.

Zokes. I am a Muslim. People in my family have fought in the British army in Afghanistan.
If you feel strongly about something try and keep your comments on topic and not post as an attack another person.

Surprised at the rabidness of the greenies - seems to stem from a heightened sense of self importance

If you feel strongly about something try and keep your comments on topic and not post as an attack another person.

Ok if you are not a troll then you are not that bright

Any one know how long until fossil fuels run out?

Why are you surprised mega? STW is merely reflecting the real world. A little understood topic (nb, Met Office's description of the current state of knowledge on natural cycles) combined with massively entrenched and polarised positions. Question any side at your peril!!!!!

Any one know how long until fossil fuels run out?

Even in human time scales, not long.

Actual time frame isn't really know. Any figure given will be a guess, some educated, others less educated.

Still, not like we rely on fossil fuels for much.

allmountainventure - Member

Any one know how long until fossil fuels run out?

chuffing ages.

coal? - we've got loads of it.

gas? - we've got loads of it.

oil? - well, we've got something like 70ish* years of the kind of stuff that we buy from saudi arabia, but there's a mind boggling amount when we include all the stuff that needs a bit more processing - tar sands, oil shale, etc. (see Alberta)

(*if you add up all the claimed reserves, and divide it by the annual consumption, then we've got almost exactly 100 years left, but it's generally accepted that most countries are a bit optimistic when they're asked how much they've got...)

exactly 100 years left

We have very different ideas of "chuffing ages"

but that's just the easy stuff.

there's much more than that when you look at oil/tar sand/shale, much much more.

many hundreds of years worth.

of all the important natural resources that we'll run out of, fossil fuels are way down the list.

many hundreds of years worth.

Sorry, Im probably not coming across how I'd like.

By human time scales I'm talking millennia.

sorry, i'm probably being a bit flippant.

my point is that we cannot rely on the depletion of fossil fuels to curb our use in such a way to limit the impact of climate change.

There are going to be Energy Wars well before the natural hydrocarbon reserves actually "run out". If we don't pull our fingers out, and invest in a generation system that has sufficient power density (nuclear for example) to support our ever growning power consumption, it's going to get messy!!

For example, when asked in a survey, "Would you like wind turbines or a Nuclear power station to be built" most people naturally answer "wind turbines". But, that isn't the real question, which should be "Would you like wind turbines and rolling blackouts in your power supply, or nuclear power generation and no blackouts". I'd bet the answer would be very different.......

Of course, some things are really going to struggle without cheap abundant hydrocarbon fuels, for example, air transport. Battery electric plane anyone? (too heavy to fly, and only can taxi for 12miles before the battery is flat 😉

Speaking of which, any seen owt about the remake of Mad Max?

I reckon the Energy Wars started around twenty years ago.

Why are you surprised mega? STW is merely reflecting the real world.

A little understood topic

combined with massively entrenched and polarised positions. Question any side at your peril!!!!!

Its funny how global warming is the right wing [non scientist] conspiracy and really i did expect better of you THM

We dont always agree but i always had you down as a rationalist who followed the evidence

Indeed JY - rationalist who "tries" to follow the evidence and dislikes calling others who disagree "not very bright" 😉

A "little understood topic" - not my words, the words of Met Office. Happy to take their word for it, they are scientists after all 😉

Happy to take their word for it

When it suits you. 🙂

I know, confirmation bias DD. I'm uniquely affected by it. 😉

A "little understood topic" - not my words, the words of Met Office.

I am genuinely surprised you are doing this

imagine TJ did this over say OBR revising the growth figures after they have more data- i feel sure you would be saying exactly the same things as you are here.

The same things can be said they go it wrong before,no one really understands, its poor modelling etc

Get on with enjoying your life, be sensible

Exactly. I would say not filling the air with pollutants would come under 'sensible'.

Imagine if CO2 was a sicky green colour, smelled nasty but was otherwise harmless. I think we'd have found a way to sort it out pretty quickly.

What all of us do all day every day is the equivalent of throwing McDs wrappers out of the car window. That would get universally condemned on here and anywhere else. Just because we can't see CO2 people go a little bit stupid.

I've not bothered reading any of the above but suggest that global warming must be a good thing. The melting polar caps release more water to turn to rain. So more for the increasing population to drink, as long as they move to the right areas.

you want to alter my opinion simply present some data that refutes the current scientific consensus

Well, the key problem is that the observed data does refuse to fit the current scientific consensus, and the IPCC modelled predictions have had to be [i]repeatedly[/i] revised downwards.

Trenberth to Mann Email:

[i]The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t. The CERES data published in the August BAMS 09 supplement on 2008 shows there should be even more warming : but the data are surely wrong. Our observing system is inadequate. [/i]

Notice that - the data is/are (a whole other argument) wrong - which flies against one of the key principles of science, that when scientific data fails to support a theory, then one may have to rethink the theory!

the key problem is that the observed data does refuse to fit the current scientific consensus*

well if a quote from the climategate hack does not disprove then I dont know what does.
Even you accept its only may so not the strongest point you will ever make
* is it really your view that data does not match the view of all the scientists and they have all just made a big mistake - should be a piece of piss to prove that.

My bold

Eight committees investigated the allegations and published reports, finding no evidence of fraud or scientific misconduct.[15] However, the reports called on the scientists to avoid any such allegations in the future by taking steps to regain public confidence in their work, for example by opening up access to their supporting data, processing methods and software, and by promptly honouring freedom of information requests.[16][b] The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations[/b]

* that is just not true

 

maxtorque - Member
There are going to be Energy Wars well before the natural hydrocarbon reserves actually "run out". If we don't pull our fingers out, and invest in a generation system that has sufficient power density (nuclear for example) to support our ever growning power consumption, it's going to get messy!!

so where are you getting the uranium from in this plan of yours to avoid energy wars?

So are we talking thousands of years of fossil fuels or hundreds?

Molgrips has a point. I've just lit my wood burner so it's stinking out the street and filling the air with fine particles that are very unhealthy, but it's carbon neutral.

are we talking thousands of years of fossil fuels or hundreds?

Hundreds with ever harder ways of getting to it - Arctic oil or fracking gas for example

I think the more worrying figure is it takes an estimated 3 million years for the earth to form 1 years worth of fossil fuels at current consumption levels.

http://www.slate.com/blogs/bad_astronomy/2013/01/14/no_global_warming_for_16_years_debunking_climate_change_denial.html

Nice link but the deniers do like to use the record high year id el nino in 98 as the start point [ though iirc we had 8 out of the 10 hottest years on record in the intervening period!]

[img] http://www.woodfortrees.org/graph/wti/from:1998/plot/wti/from:1998/trend:1998 [/img]

rather than
[img] http://www.woodfortrees.org/graph/wti/from:1907/plot/wti/trend:1907 [/img]

then then moan about cherry picking data

The issue for fossile fuels is likely to become economic before it becomes actually scarce. (In someways it already is).

For example, battery electric cars are currently un-economic compared to conventional cars, but if fuel prices doubled, which they easily could (harder to find, extract, refine poor quality crude supplies, and more people wanting it (commercial pressures), then those uneconomic batteries suddenly become viable!

Ignoring the climate change arguments, moving to a more renewable or a higher energy density system is only a good thing in the long run. Funnily enough, the very thing that has made certain Gulf states rich on oil money, could also make them rich on renewables (lots of sunlight = lots of photosynthesis = lots of plant matter = lots of oil, But now, lots of sunlight = >solar energy generation (via various methods))

Nice link but the deniers do like to use the record high year id el nino in 98 as the start point [ though iirc we had 8 out of the 10 hottest years on record in the intervening period!]

What you can't get away from, is that the recognised and accepted modelled predictions laid forth by the experts in the field were for a continued increase throughout this period and this has not only spectacularly not happened, but the models have been revised downwards to reflect this.

Which means that the predictions and modelling that we have been told were reliable, consensus, and based on the best science available were fundamentally wrong.

so Junky, if the predictions were wrong two years ago, have been continually wrong in their predictions for the past sixteen years, then why on earth do you feel that they can be relied upon now?

I like your use of "spectacularly" and "fundamentally". Lends you more credibility, so it does. Keep it up!

So, you're actually disagreeing, or saying I'm wrong? or just relying on passive-aggressive faint praise to try and dismiss an argument which is factually correct?

Can you show anything to support your claim that the models are inaccurate then?

Let's forget adverbs. Everybody knows they're the tool of the lazy writer. So let's see your best graphs then.

[img] [/img]

Red line is the model, blue line is the actual:

[img] ?w=640&h=397[/img]

is that the recognised and accepted modelled predictions laid forth by the experts in the field were for a continued increase throughout this period and this has not only spectacularly not happened, but the models have been revised downwards to reflect this.

Which means that the predictions and modelling that we have been told were reliable, consensus, and based on the best science available were fundamentally wrong.

so Junky, if the predictions were wrong two years ago, have been continually wrong in their predictions for the past sixteen years, then why on earth do you feel that they can be relied upon now?

dismiss an argument which is factually correct?

Notice that - the data is/are (a whole other argument) wrong - which flies against one of the key principles of science, that when scientific data fails to support a theory, then one may have to rethink the theory!

The worrying thing is that you clearly have no idea how science works. It is equally possible that measurements are not accurate enough - especially when it comes to measuring fractions of a degree, averaged across the planet.

This is a common argument between modellers and empiricists. A model may only be as good as the data that feeds it, but it is also a fallacy to assume that measurements are perfectly accurate. In which case, predictions from a model based on correct theory may on occasion give more correct results than apparent measured values.

People get too caught up in the temperature thing and fail to see the wood for the trees. A lot of us on this forum have been around for half a century or so - what have you experienced? I've come to expect more storms that are more intense, more freak weather events, more humid Summers, less snow at low altitudes.

It's not just my imagination; I spent some time checking climatic data and the winters of my youth were colder, the Summers were drier. It's all on the Met Office site and Méteo de France. No flooding events in my local area from 63 to 82, 13 since 82.

I'm in a part of the world in which the climate is getting warmer, some parts are getting cooler and overal ther's a smalll warming. What we mustn't lose sight of is that there is climate change and the changes are consitent with a higher energy regime in the atmosphere as predicted by a greenhouse gas model.

predictions from a model based on correct theory may on occasion give more correct results than apparent measured values.

I'm just going to get my head around that for a minute. 🙂

In the meantime, I thought I'd read somewhere that current models have been quite successful in "predicting"* temperatures back to around 1800, no?

*I'm not sure how one describes "predicting" the past, but you know what I mean.

well its easier to predict the past as a rule DD
shortest assesment is here

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-8-1.html

[img] [/img]
FAQ 8.1, Figure 1. Global mean near-surface temperatures over the 20th century from observations (black) and as obtained from 58 simulations produced by 14 different climate models driven by both natural and human-caused factors that influence climate (yellow). The mean of all these runs is also shown (thick red line). Temperature anomalies are shown relative to the 1901 to 1950 mean. Vertical grey lines indicate the timing of major volcanic eruptions. (Figure adapted from Chapter 9, Figure 9.5. Refer to corresponding caption for further details.)

I'm just going to get my head around that for a minute.

Another way of putting it would be that models based upon long term data may be more accurate than new short term data.

But it's late here, and I've a carbon sequestration grant to finish writing before I can go to bed

Where are you zokes? Are you in Aus? Seems like the local press are stirring things up a bit today!

I bet a lot of people would love that quote - "models based upon long term data may be more accurate than new short term data." A new avenue for willy-waving!

Yeah, I get ya zokes.

Sleep tight.

Sleep tight.

Sleep is something I'm dreaming about!

Whoever came up with the idea of turning harmless pdf documents into "SmartForms" needs rodgering sideways with a baseball bat wrapped in razor wire.

Then they should be shot to death, repeatedly.

He is from Bolton area originally but was driven from these fine shore by the drastic cuts in science

He is indeed in Oz.

Yours
Stalker 😉

I've been spending a little time reading some of the internet info on this subject (nothing too taxing for my tiny mind so sorry to the better informed in advance.)
It is widely accepted that the Ice Core data is our best indicator of natural cycles over the last 400 thousand years [img] [/img]
/p>

It is widely accepted that the current short term but accelerated rate of warming is due to man made climate change due to the earth being sensitive to very small atmosphere changes (It looks as though there is still debate to be had on how much we really know abut the earths atmosphere, how sensitive it is and how the Earth will cope with these changes.)

Some of you seem to be suggesting that we should do everything we can to get the cooling going again.. Why?

Some of you seem to be suggesting that we should do everything we can to get the cooling going again.. Why

Do you mean why do we think Global warming is a bad thing?

As for the "cooling going again" what exactly does this mean?

theocb - Member
Some of you seem to be suggesting that we should do everything we can to get the cooling going again.. Why?

Junkyard - Big Hitter
As for the "cooling going again" what exactly does this mean?

i think theobc is referring to the chart/s he posted, from that it looks like we're due another slow slide into an ice age.

(in a similar way: we're due another north/south pole reversal. It might not happen, but they've been spookily regular and reliable upto right now)

theo: i'm an idiot, my understanding of these things is limited by own stupidity.

here's how i grasp it:

life as we know it has evolved/survived within the temperature range shown on the chart/s you posted.

and, as is suggested, the temperature range is at least partly affected by the CO2 content of the atmosphere.

it's one thing for the earth's life-forms to slowly re-adapt to an atmosphere/temperature range their ancestors survived relatively recently (in evolutionary terms).

it's quite another asking them to quickly adapt to an atmosphere/environment not seen for many millions of years.

maybe everything will be fine.

maybe things could get a little tricky.

is caution such a bad thing?

On theobc's graph, the present = 1950. How much warmer than the 1950 temperature did the natural cycle take us? How much higher are we now predicted to get?

The post glacial climatic optimum ended about 5000 tears ago. Overall it was 1 or 2°C warmer but some areas benefited more than others with northern continental ares being several degrees warmer. If you Google "climatic optimum" you'll find lots of info.

In terms of CO2 were now up to 330ppm which is off the graph. Again Google will be more accurate than my memory.

Yes, we were heading for another ice age which according to some was overdue. Clearly that wouldn't have been a good thing. Getting above the range that we know gives the best growing conditions over the greatest land area isn't a good thing either even if Britain feels a bit chilly most of the year. Back in the climaitic optimum it was very wet and humid as the peat bogs testify.

So, you're actually disagreeing, or saying I'm wrong? or just relying on passive-aggressive faint praise to try and dismiss an argument which is factually correct?

I was using sarcasm.

I think the CO2 levels are over 390ppm now but I don't think the temp has followed quite as sharply just yet.
Yes as ahwiles (and Edukator) said. The graphs show a natural cycle over the last 400 thousand years and it appears as if we should now be rapidly heading for a much cooler climate.
I was just asking why one way is perceived to be better than the other?
I do appreciate and understand the side of not knowing how the Earth and fauna/flora will respond if we go over it's (short term) historical limits but we know that living things began in much harsher environments in the distant past so why try to maintain the current living things as if they will be the last or the best?

What are we actually trying to achieve by reducing our impact? Are we trying to reverse or prolong the process?

What I'm thinking in Basic terms:-

If we continue to have an effect on warming then the world will become hostile then population will decrease, CO2 will drop sharply and we will head for hostile icy times

If we reverse our impact on the climate then it looks as though we should be heading for hostile icy times

If we try and control climate at a level that suits humans then the Earth is doomed because we will devour it.
Sh1t the bed I'm off for a drink, it don't look good.
Seriously though what are the options on the table and their outcomes?

If we continue to have an effect on warming then the world will become hostile then population will decrease, CO2 will drop sharply and we will head for hostile icy times

Once in the atmosphere CO2 is extremely persistant. Levels won't drop sharply in response to a drop in human activity. What we've already released will affect climate for the next thousand years or so - or longer depending on the model.

My point wasn't a fully fledged theory as I'm sure you can see. 😀
Sharply on a long term scale. A significant drop over 10000 years is sharply on a scale of hundreds of thousands of years. VOSTOK data shows potential for a significant drop over this time frame and also shows potential for natural temp swings of 20 degrees in the same time period. Temperature will reduce much quicker than the CO2

I see 3 options and none of them are perfect. How do we know what's best?

Temperature will reduce much quicker than the CO2

Again, not so. Google it;

Hang on, this time I'll Google it myself.

Edit: no I won't it'll take me ages to find a reference anyone here would accept. Google something about the same buffers that slow temperature response to increasees in CO2 also slow the temperature response to falls in CO2. Then consider you have turned over the oceans and changed ocean circulation patterns and things could take a very long tiem indeed to mend.

no I won't it'll take me ages to find a reference anyone here would accept

Chuckles

your not wrong on either point

(in a similar way: we're due another north/south pole reversal. It might not happen,[b] but they've been spookily regular and reliable upto right now)[/b]

Shenanigans!

@Edukator; I disagree 😉 my source is basic historic ice core data so where did you get your info from. (you bleeding google it if you want to say I'm wrong, I think that is the STW way :D) It's really not important but feel free to carry on because I'm happy to learn.(email me some links)

Regardless of that what are you saying the options are? Don't all the options come with baggage? Is one clearly the favourite?
Surely anyone who has a basic understanding of this Global Warming problem will be able to tell me in simple terms what the options and perceived outcomes are.
I completely understand if you have had enough of explaining basic stuff to the ignorant but this all seems a bit odd, people all over the web can argue till the cows come home about the facts of manmade climate change but no one has any info on the outcome of our master plan.