Global warming slowing down??

Akrasia

Weathering wrote: »

And one or two cold winters could increase and thicken it further. You are speculatining. Both of arguments are pointless, it is what it is now.

It's not speculation. The arctic sea ice is weak and vulnerable to collapse, and it is grossly dishonest for the Daily Mail or anyone else to claim that 2 years of 'recovery' from the record minimum extent ever is somehow evidence that global warming is (insert propaganda here) when ALL of the evidence points towards a trend that will see summer ice free arctic conditions sooner rather than later.

It could take 5 years, or 10 years, or even 50 years, but all the data points towards this conclusion. If you have any credible scientific research that shows that the sea ice is likely to recover to (lets say) pre 1990 levels you're welcome to post it here and we can discuss it.

FWVT

Thargor wrote: »

On the website of every agency that moniters these things? Are you just trolling at this stage?

No, but the mods will decide that, not you. Thank you for posting an up do date graph, that's all I ask. Nothing more. You're trying to find smoke without the fire.

Frank Lee Midere

Akrasia wrote: »

It's not an over reaction to say that a nuclear war between russia and the U.S could end life as we know it on earth

Neither is it an over-reaction that runaway climate change could prove catestrophic for life on earth. Venus is not the kind of atmosphere we should emulate.
It's a spectrum, If we can limit global warming to below 2 degrees above 1900's temperature, then we will have some negative effects and there will be environmental damage, but we should be able to cope by adapting to the new conditions

At 2 degrees, we'll see worse consequences but still, if we can limit it to 2 degrees, managable (hopefully)

But we are still incertain of what the climate sensitivity to doubling the earth's CO2 concentration will be. The range of probability is between 2 degrees (best case scenario) and 4.5 degrees (realistic worst case scenario) If we are very lucky and can limit out CO2 emissions AND the best case scenario climate sensitivity is correct, then we'll scrape through this by the skin of our teeth. If we're unlucky and we're facing 4.5 degrees warming, then we're looking into the jaws of another global extinction event. it's genuinely that serious.
http://skepticalscience.com/climate-best-to-worst-case-scenarios.html

However these best and worst case scenarios are based on models which may be wanting. The IPCC reduced their best case to less than 2% in the last report.

Unless warming is back loaded the 4.5 % should be seeing about half a degree a decade.

That said we should of course try and replace fossil fuels, the sooner the better.

Weathering

Akrasia wrote: »

It's not speculation. The arctic sea ice is weak and vulnerable to collapse, and it is grossly dishonest for the Daily Mail or anyone else to claim that 2 years of 'recovery' from the record minimum extent ever is somehow evidence that global warming is (insert propaganda here) when ALL of the evidence points towards a trend that will see summer ice free arctic conditions sooner rather than later.

It could take 5 years, or 10 years, or even 50 years, but all the data points towards this conclusion. If you have any credible scientific research that shows that the sea ice is likely to recover to (lets say) pre 1990 levels you're welcome to post it here and we can discuss it.

I already answered this??? Why ask again???? I have already stated my opinion on the page before. I'm not a parrot I'm off for a bit

Akrasia

Weathering wrote: »

Once again I already answered this. I gave other links running the exact same story as the daily mail but you forgot to mention those as you want to belittle the facts as much as you can. Summer Sea ice increased by 43% since summer 2012 that is fact and it is also fact the daily mail mail reported this for this I am sorry

The three links you posted, the first was the Daily Mail, the second was an american blog that used the daily mail as it's only source, and the third was some macedonian site that didn't give any source, but judging by their al gore references, they almost certainly just parroted the daily mail too. That's three rubbish sources, which are ultimately just mirrors of each other.

Ice extent increased by 43%, ice mass was well below that, and a 43% increase from the record low, is about as comforting as an Irish Bank CEO being told their share price is up 200% to 4 cents a share having previously traded at 12 euros a share.

Even after a 43% increased sea ice extent was still the 5th or 6th lowest ever recorded value

Professional Climate change deniers do this All the time. It's a broken record at this stage. They take a record breaking bad year for something, wait until the next year when 'regression towards the mean' means the values are less extreme than the year before, and then they declare that global warming has stopped or is in reverse.

Akrasia

Frank Lee Midere wrote: »

However these best and worst case scenarios are based on models which may be wanting. The IPCC reduced their best case to less than 2% in the last report.

Unless warming is back loaded the 4.5 % should be seeing about half a degree a decade.

That said we should of course try and replace fossil fuels, the sooner the better.

Unfortunately, the warming will probably be backloaded, so that even if we suddenly stopped producing any greenhouse gasses, we would continue to see increases in global temperatures as the climate finds a new equilibium.

The effect of trapping excess heat is cumulative and it builds up to equal what the natural climate sensitivity is for whatever the new atmospheric composition and albido effects there will be in the future.

Greatly reducing Fossil fuel emissions would be an amazing start, but I believe we will also need to invest very heavily in sequestring excess carbon from the atmosphere as part of a mitigation strategy in the future

FWVT

Akrasia wrote: »

Unfortunately, the warming will probably be backloaded, so that even if we suddenly stopped producing any greenhouse gasses, we would continue to see increases in global temperatures as the climate finds a new equilibium.

The effect of trapping excess heat is cumulative and it builds up to equal what the natural climate sensitivity is for whatever the new atmospheric composition and albido effects there will be in the future.

Greatly reducing Fossil fuel emissions would be an amazing start, but I believe we will also need to invest very heavily in sequestring excess carbon from the atmosphere as part of a mitigation strategy in the future

Ah now come on, that last bit is a bit OTT.

Just another point on all this, carbon dioxide is alleged culprit, not carbon! Carbon is an element, without which we would not exist. Kids are growing up now being told that "carbon" is bad. Correct term, please

Rikand

Supercell wrote: »

Not sure it its already posted on this thread. Here's an excerpt from an interesting article on News Scientist - No more pause: Warming will be non-stop from now on

Maybe the volcanoes in Iceland are trying to sort this out for us so :pac:

Godge

Thargor wrote: »

Yes I did read it, I even posted a 30 year graph showing the catastrophic ice loss in the Arctic, you posted an article that zooms in on a 2 year period that showed growth as a result of a cold Arctic summer in 2013, this is a common tactic from outlets such as the daily mail, zooming in on tiny time periods or geographical areas and ignoring the mountains of evidence elsewhere, you wont find scientific consensus agreeing with that article that either polar cap is doing well, well they might agree that it expanded in 2013 but doesnt that seem slightly irrelevant next to graphs like this?

2013 shows an upturn, 2014 will show a further upturn, it will be the highest extent since 2006.

Yet the volumetric data shows a different story with a continued decline.

The problem that the climate change advocates have is that they previously relied on the "extent" data rather than the "volume" data presumably because that appealed to the Daily Mail generation that the Northeast and Northwest passages would soon be open water. When the extent slowed down and reversed, they switched to the volume data.

To me there is no doubt that the climate is changing. That is what climate does. To me there is also no doubt that humanity is influencing climate change.

But that is where my doubts start. Is the influence of man greater than natural variability? Is climate change necessarily a bad thing? Sea level rises are a bad thing but much of what I have read suggests that the 3-4m rises needed to cause catastrophic issues will take thousands of years as the Antarctic and Greenland land ice will not melt overnight. Melting of sea ice doesn't change sea level.

Methane from permafrost? Will someone in Russia will find a way of harvesting that methane and selling it to the West?

Runaway climate change in a short period is possibly the greatest risk but that relies on certain assumptions that are not always bourne out by the historical evidence i.e. it takes longer than they think.

So to sum up. Humanity influenced climate change is happening. However, despite what many say, the consequences this century may not be significant and that means time is there to find solutions.

Remember, our ancestors three thousand years ago started organised agriculture and started the process of climate change and extinction. We have managed to survive the last 3,000 years, why not the next?

Akrasia

FWVT wrote: »

Ah now come on, that last bit is a bit OTT.

Just another point on all this, carbon dioxide is alleged culprit, not carbon! Carbon is an element, without which we would not exist. Kids are growing up now being told that "carbon" is bad. Correct term, please

The act of sequestering CO2 from the atmosphere is called carbon sequestration. It's the correct term. Yes, the aim is to extract excess carbon dioxide from the air, but it is not necessary to store the CO2 as CO2, only the Carbon part needs to be sequestered and we are fine to release the oxegen back into the atmosphere. (one suggested way of sequestering CO2 is create charcoal using 'pyrolysis' and then bury it underground where it locks away the carbon. Another way is to just plant trees where the trees convert the carbon in the air, into biomass

Akrasia

Godge wrote: »

2013 shows an upturn, 2014 will show a further upturn, it will be the highest extent since 2006.

Yet the volumetric data shows a different story with a continued decline.

The problem that the climate change advocates have is that they previously relied on the "extent" data rather than the "volume" data presumably because that appealed to the Daily Mail generation that the Northeast and Northwest passages would soon be open water. When the extent slowed down and reversed, they switched to the volume data.

It's actually the opposite. People who advocate action to mitigate global warming have always focused mainly on the volume of ice rather than the extent of the ice. The Daily mail and other denialist publications love to periodically report on 'increases' in ice extent (they do it every single time the line on a jagged graph is going up) and they consistently ignore all the reports that the volume of ice in the arctic is plumetting year on year

They absolutely love stories about the East antarctic ice sheet which was gaining mass, but they never mention the fact that west Antarctica is losing mass much more rapidly than the east is gaining.

The fact that they consistently report on only events that fit their version of the story and completely ignore the bigger picture is the reason why they are widely mocked in sceptical circles. The Daily Mail is akin to the weekly world news whenever science is concerned. (They're world leaders in celebrity gossip and horseracing coverage though, also, their crossword is moderately entertaining)

To me there is no doubt that the climate is changing. That is what climate does. To me there is also no doubt that humanity is influencing climate change.

But that is where my doubts start. Is the influence of man greater than natural variability? Is climate change necessarily a bad thing? Sea level rises are a bad thing but much of what I have read suggests that the 3-4m rises needed to cause catastrophic issues will take thousands of years as the Antarctic and Greenland land ice will not melt overnight. Melting of sea ice doesn't change sea level.

The range of possible sea level rise between now and 2100 is between 20 centimetres and 200 centimetres with the most probable figure being about 1 metre. This kind of range is confusing, but essentially, what it means is, statistically, it's as likely that the global sea levels will rise by 2 metres, as it is that they will rise by 20 centimetres, or in other words, it is just as likely that the sea levels will increase by more than 1 metre as it is that they will be less than 1 metre.

At 1 metre sea level increase, you're looking at much more widespread flooding following storms and heavy rain.

Of course, the sea level rises will not stop in 2100, they will continue to rise for as long as thermal expansion and glacial melting continues

Methane from permafrost? Will someone in Russia will find a way of harvesting that methane and selling it to the West?

Anything's possible, but the gas will be literally seeping from the thawing soil over tens of thousands of inaccessable tundra. It's hard to see how anyone could develop an economical method for capturing any significant quantity of this gas

Runaway climate change in a short period is possibly the greatest risk but that relies on certain assumptions that are not always bourne out by the historical evidence i.e. it takes longer than they think.

Yep, there are a lot of uncertainties. Unfortunately, there are also a lot of possible positive feedbacks. The simplest one is that as ice melts, the surface reflects less heat and accellerates warming locally, which further speeds up melting...

It's possible that there could be some negative feedbacks, for example, maybe algae will bloom in the ocean and sequester carbon this way, but nobody knows for sure and the consequences are so serious we should probably not just leave it to chance

So to sum up. Humanity influenced climate change is happening. However, despite what many say, the consequences this century may not be significant and that means time is there to find solutions.

Remember, our ancestors three thousand years ago started organised agriculture and started the process of climate change and extinction. We have managed to survive the last 3,000 years, why not the next?

Despite my postings on here, i'm actually a bit optimistic because I know how fast our technology is improving. But the main problem is that the longer we leave it, the more and more irreversible it becomes. There should be a sense of urgency because, while we can mitigate lower level global warming, we are powerless to prevent the major impacts on our biosphere once they become self sustaining.
In terms of tehnology, We're good, but we're not that good. (yet)

FWVT

Akrasia wrote: »

The act of sequestering CO2 from the atmosphere is called carbon sequestration. It's the correct term. Yes, the aim is to extract excess carbon dioxide from the air, but it is not necessary to store the CO2 as CO2, only the Carbon part needs to be sequestered and we are fine to release the oxegen back into the atmosphere. (one suggested way of sequestering CO2 is create charcoal using 'pyrolysis' and then bury it underground where it locks away the carbon. Another way is to just plant trees where the trees convert the carbon in the air, into biomass

My carbon comment more general, not just aimed at you. Yes, carbon sequestration is correct, but I really meant people saying we're putting too much carbon into the atmosphere, carbon tax, etc.

FWVT

Akrasia wrote: »

The range of possible sea level rise between now and 2100 is between 20 centimetres and 200 centimetres with the most probable figure being about 1 metre. This kind of range is confusing, but essentially, what it means is, statistically, it's as likely that the global sea levels will rise by 2 metres, as it is that they will rise by 20 centimetres, or in other words, it is just as likely that the sea levels will increase by more than 1 metre as it is that they will be less than 1 metre.

At 1 metre sea level increase, you're looking at much more widespread flooding following storms and heavy rain.

Of course, the sea level rises will not stop in 2100, they will continue to rise for as long as thermal expansion and glacial melting continues

You reckon 1 metre by 2100??? Wow, that's some statement, given that we've only seen a fraction of that in the last 140 years. Even given the slightly increasing rate, I still find it hard to believe another metre in the next 85 years.

Danno

Thargor wrote: »

Except the trend shows thats not the case, its getting worse over time, this is observed fact. You thinking its going to suddenly turn around for the better are the one who's "speculatining". what can you not grasp here?

Your chart is total BULL.



The 1964 data in this chart is from the recovered NIMBUS satellite data. Your chart above shows NO data in the 1960s being in the 6M to 7M range, in fact, your chart shows no year in the 1960s being below 9.5M.

This year's ice minimum is running 20% lower than in 1964 and roughly 15% below average.

Akrasia

FWVT wrote: »

You reckon 1 metre by 2100??? Wow, that's some statement, given that we've only seen a fraction of that in the last 140 years. Even given the slightly increasing rate, I still find it hard to believe another metre in the next 85 years.

[IMG][/img]http://static.skepticalscience.com/images/Sea-Level-1.gif

Here's a link to the IPCC summary on sea level rises
http://www.ipcc.ch/pdf/unfccc/cop19/3_gregory13sbsta.pdf

The Rate of sea level rises during 1901-1990 was
1.5 [1.3 to 1.7] mm yr-1

Rate of sea level rises during 1993-2010 was
3.2 [2.8 to 3.6] mm yr-1
.
It is projected that the rate of increase for the last 20 years of the century will be 0.40 [0.26–0.55] m for RCP2.6 (best case scenario where we limit global emissions starting immediately), or 0.63 [0.45–0.82] m RCP8.5 where global policy drags and emissions continue on their current path of constantly increasing atmospheric CO2 concentrations

Even the most optimistic projection has sea levels expanding 2.6 times faster at the end of this century compared to last century. The BAU model has sea levels increasing more than 4 times faster

(For more info on the RCP scenarios the link below is very usefuk
http://www.skepticalscience.com/rcp.php?t=3
.

FWVT

Akrasia wrote: »

Here's a link to the IPCC summary on sea level rises
http://www.ipcc.ch/pdf/unfccc/cop19/3_gregory13sbsta.pdf

The Rate of sea level rises during 1901-1990 was
1.5 [1.3 to 1.7] mm yr-

Rate of sea level rises during 1993-2010 was
3.2 [2.8 to 3.6] mm yr-1

Interesting to note (in my graph above) your choice of comparing a 90-yr period versus a 17-yr period. This handy selection fails to highlight the marked increase in rate due to the warming from 1925-1960, which started the upward trend but which was not down to human influences. This rate is about the same as the rate today, despite the alleged increase in human-induced warming and land-ice-melt now, which should be causing an almost runaway vertical slope if some are to be believed.

It is projected that the rate of increase for the last 20 years of the century will be 0.40 [0.26–0.55] m for RCP2.6 (best case scenario where we limit global emissions starting immediately), or 0.63 [0.45–0.82] m RCP8.5 where global policy drags and emissions continue on their current path of constantly increasing atmospheric CO2 concentrations

Even the most optimistic projection has sea levels expanding 2.6 times faster at the end of this century compared to last century. The BAU model has sea levels increasing more than 4 times faster

(For more info on the RCP scenarios the link below is very usefuk
http://www.skepticalscience.com/rcp.php?t=3
.

A very different observation is being projected in the actual measured data.

Oneiric 3

Akrasia wrote: »

The Daily mail and other denialist publications love to periodically report on 'increases' in ice extent (they do it every single time the line on a jagged graph is going up) and they consistently ignore all the reports that the volume of ice in the arctic is plumetting year on year

Absolutely agree with this. The Daily Mail, as with other low quality media outlets, quite clearly have their own agenda and blatantly profit from disinformation and the promotion of ignorance, not just on the climate issue, but on everything else as well.

Unfortunately, the 'other side' are not blameless either. It has become the norm now to associate every single major weather event with climate change - even if the climate change influence is downplayed by scientists.
"We can expect more of this type of weather' or 'to early to say if climate change influences had an input in this particular event' and so forth.

Whether it is right or not, or whether we like it or not, most of the population receive most or all of their information on climate change via the mass media, and this is how their ideas on it are shaped. Of course we could say well 'read the science paper' to get the real picture, but this also is not practical. You just cannot expect ordinary people to sit down and take the time read, often indecipherable, academic research papers (that is, if they can afford the huge charge newly released research papers have on them in the first place)

Both sides are equally as guilty of distorting actual facts in order to promote their particular cause. It really does not matter which side feels have the moral high ground. Distorting scientific fact to fit ones own personal crusade is not science no matter how it is glossed up or justified. It is deception, pure and simple.

Akrasia

Oneiric 3 wrote: »

Absolutely agree with this. The Daily Mail, as with other low quality media outlets, quite clearly have their own agenda and blatantly profit from disinformation and the promotion of ignorance, not just on the climate issue, but on everything else as well.

Unfortunately, the 'other side' are not blameless either. It has become the norm now to associate every single major weather event with climate change - even if the climate change influence is downplayed by scientists.
"We can expect more of this type of weather' or 'to early to say if climate change influences had an input in this particular event' and so forth.

Whether it is right or not, or whether we like it or not, most of the population receive most or all of their information on climate change via the mass media, and this is how their ideas on it are shaped. Of course we could say well 'read the science paper' to get the real picture, but this also is not practical. You just cannot expect ordinary people to sit down and take the time read, often indecipherable, academic research papers (that is, if they can afford the huge charge newly released research papers have on them in the first place)

Both sides are equally as guilty of distorting actual facts in order to promote their particular cause. It really does not matter which side feels have the moral high ground. Distorting scientific fact to fit ones own personal crusade is not science no matter how it is glossed up or justified. It is deception, pure and simple.

It's the media. I have heard the same question asked over and over again 'is this storm because of global warming' and every single scientist I have ever heard answer this question has said the following 'It is impossible to attribute individual weather events to global warming, but global warming makes these kinds of extreme events more likely'

The fact of the matter is that every single weather event is affected by global warming. Weather is a chaotic dynamic system. It's a pretty meaningless question to ask what caused a particular weather event. The answer is always 'every other weather event since the planet formed caused this weather event'

Akrasia

FWVT wrote: »

Interesting to note (in my graph above) your choice of comparing a 90-yr period versus a 17-yr period. This handy selection fails to highlight the marked increase in rate due to the warming from 1925-1960, which started the upward trend but which was not down to human influences. This rate is about the same as the rate today, despite the alleged increase in human-induced warming and land-ice-melt now, which should be causing an almost runaway vertical slope if some are to be believed.



A very different observation is being projected in the actual measured data.

When you project these rises into the future, are you using the current rate of sea level increases or do you accept that the rate of increase will get faster due to the cumulative nature of the greenhouse effect?

FWVT

Akrasia wrote: »

When you project these rises into the future, are you using the current rate of sea level increases or do you accept that the rate of increase will get faster due to the cumulative nature of the greenhouse effect?

I'm using the fact that we are on an increasing natural underlying trend over the past few hundred years and we have so far not done anything to increase the rate of increase. This natural trend will of course continue for a long time to come but the recent obsevations of record land-ice melt are being countered by more powerful natural forces, which are causing a leveling off. It will pick up again, no doubt, but to go for 1 metre in the next 85 years is asking an awful lot of anthropogenic forcings to cause the 12mm/year+ required to carry it off. This is in line with the highest rates ever recorded, and a hell of a lot greater than the current rate. It just won't happen by 2100.

Akrasia

FWVT wrote: »

I'm using the fact that we are on an increasing natural underlying trend over the past few hundred years and we have so far not done anything to increase the rate of increase. This natural trend will of course continue for a long time to come but the recent obsevations of record land-ice melt are being countered by more powerful natural forces, which are causing a leveling off. It will pick up again, no doubt, but to go for 1 metre in the next 85 years is asking an awful lot of anthropogenic forcings to cause the 12mm/year+ required to carry it off. This is in line with the highest rates ever recorded, and a hell of a lot greater than the current rate. It just won't happen by 2100.

Firstly, That graph seems to assume that the rate of acceleration of sea level rises will not change. THe IPCC are almost certain that the rate of sea level rises will definitely increase under all scenarios in the short term and under the pessimistic scenarios, the rate of sea level increases will be much faster than they are today.

Also, I'd like to know where you get the information that sea level increases are within the natural range. According to the IPCC, in the last 7000 years, there has been about a 2 to 3 meter rise in global sea levels, and there is no evidence of any change plus or minus about 25mm over the period of several hundred years during this timescale. (medium, confidence) The sea level rises since 1850 are way beyond what the geological record shows.

That graph does not show the continuation of a natural process. It shows a massive accelleration of the rate of sea level rises from about 1850 onwards. For the first 150 years the datapoints are scattered with some years higher, other years lower than the mean, but from 1850 onwards, the clusters of datapoints start to converge so that by the mid 1950s, almost every single year is a record breaking high water level.

http://www.climatechange2013.org/images/report/WG1AR5_Chapter13_FINAL.pdf?bcsi_scan_c6b2e1b18dc6970f=0&bcsi_scan_filename=WG1AR5_Chapter13_FINAL.pdf


According to the IPCC, under the RCP 8.5 (no reduction in emissions) the increases in global sea level could be as high as 16mm a year in the last 2 decades of this century which would be absolutely catestrophic for future generations because that implies global sea levels beyond 2100 will be rising at 2 or more centimeters a year.
I am choosing the upper range of the predictions here to illustrate how dangerous global warming could be, but even if we accept the lower ranges of the RCP 8.5 scenario, it just means it will take an extra few decades to reach this level of sea level rises.

What we need to be aiming for is the RCP 2.6 or RCP 4.5 scenario where we reduce emissions sufficiently to avoid the worst effects of AGW

FWVT

Akrasia wrote: »

Firstly, That graph seems to assume that the rate of acceleration of sea level rises will not change. THe IPCC are almost certain that the rate of sea level rises will definitely increase under all scenarios in the short term and under the pessimistic scenarios, the rate of sea level increases will be much faster than they are today.

Also, I'd like to know where you get the information that sea level increases are within the natural range. According to the IPCC, in the last 7000 years, there has been about a 2 to 3 meter rise in global sea levels, and there is no evidence of any change plus or minus about 25mm over the period of several hundred years during this timescale. (medium, confidence) The sea level rises since 1850 are way beyond what the geological record shows.

That graph does not show the continuation of a natural process. It shows a massive accelleration of the rate of sea level rises from about 1850 onwards. For the first 150 years the datapoints are scattered with some years higher, other years lower than the mean, but from 1850 onwards, the clusters of datapoints start to converge so that by the mid 1950s, almost every single year is a record breaking high water level.

http://www.climatechange2013.org/images/report/WG1AR5_Chapter13_FINAL.pdf?bcsi_scan_c6b2e1b18dc6970f=0&bcsi_scan_filename=WG1AR5_Chapter13_FINAL.pdf


According to the IPCC, under the RCP 8.5 (no reduction in emissions) the increases in global sea level could be as high as 16mm a year in the last 2 decades of this century which would be absolutely catestrophic for future generations because that implies global sea levels beyond 2100 will be rising at 2 or more centimeters a year.
I am choosing the upper range of the predictions here to illustrate how dangerous global warming could be, but even if we accept the lower ranges of the RCP 8.5 scenario, it just means it will take an extra few decades to reach this level of sea level rises.

What we need to be aiming for is the RCP 2.6 or RCP 4.5 scenario where we reduce emissions sufficiently to avoid the worst effects of AGW

I'm referring to natural changes since the last Ice Age, where there were rises of several metres per century.

The graph does indeed show a rising trend since 1850...but one that is totally natural and shows no sign of AGW, even in the last half century. The past 50-years period is no faster than the period before that, and in fact is becoming shallower more recently. The future projection is a continuation of the current natural increase, but even adding to that GHG forcings to get to your 16 mm/yr by the end of the century it doesn't bring us to the 1 metre you predict. Do the maths, it doesn't stack up. To go from current 3 mm/yr to 16 mm/yr, how do you get 1000 mm for the next 85 years out of that? Simple maths will tell you it's highly improbable. Wed want to be kickstarting global warming again pretty soon or we'll run out of time.

Godge

FWVT wrote: »

I'm referring to natural changes since the last Ice Age, where there were rises of tens of metres per century.

The graph does indeed show a rising trend since 1850...but one that is totally natural and shows no sign of AGW, even in the last half century. The past 50-years period is no faster than the period before that, and in fact is becoming shallower more recently. The future projection is a continuation of the current natural increase, but even adding to that GHG forcings to get to your 16 mm/yr by the end of the century it doesn't bring us to the 1 metre you predict. Do the maths, it doesn't stack up. To go from current 3 mm/yr to 16 mm/yr, how do you get 1000 mm for the next 85 years out of that? Simple maths will tell you it's highly improbable. Wed want to be kickstarting global warming again pretty soon or we'll run out of time.

I was thinking that about the figures. While I have no doubt that climate change is happening, there does seem to be some exaggeration of the timeline probably as a means to get us to do something now. It is important in looking for solutions that we have a better idea of the likely timeframe.