The interglacial ~400,000 years ago was lot hotter. And there were no SUVs or coal power plants.
“A paper published … in Palaeogeography, Palaeoclimatology, Palaeoecology finds that the last 4 interglacials were up to 3C warmer than the current interglacial and were characterized by sea levels up to 79 feet [24 meters] higher than the present. According to the authors, “The most conservative estimates of palaeo-sea level during [the interglacial ~400,000 years ago] would require an ice mass loss equivalent to all of the modern Greenland and West Antarctic ice sheets; the more extreme estimates would require additional ice mass loss from the East Antarctic ice sheet.”
Thus, during prior interglacials, sea surface temperatures were up to 3 °C warmer, sea levels were up to 79 feet higher than the present, and up to all of the Greenland and West Antarctic ice sheets melted away. All of this occurred naturally and at “safe” levels of CO2. Thus, there is no evidence that climate change within the present interglacial is any different, unprecedented, unnatural, unusual, or due to man-made CO2.”
(h/t Hockey Schtick)
sunshine hours 
You know that is a fake new. If Groenland melt, the sea would eat London, Venecia or Cartagena. Those cities existed existed 400 years ago. Do not beleive every negacionist new you read. If you are a scientist you should think a little more.
Sorry, the new sais 400.000 years ago (not 400) . I still thinking is a fake new.
Anyway, we can’t go back to 400.000 years ago. Changes are going much faster now than at andt moment. ¿Why are we taking this risk? Every scientist that study climate Knows that CO2 and CH4 make the world hotter. ¿Why do you still deny that fact? All climate chances have been because of CO2 or CH4. We are changing that faster than ever.
Come on!! Accept we are changing climate, is not that difficult. Is an evidence.
Accept we are changing climate, is not that difficult. Is an evidence. Come on!!
I accept the evidence of 1.35C over a doubling of CO2 from 1750. Everything else is natural variation.
Its such a trivial amount too. And over 350 years.
“I accept the evidence of 1.35C over a doubling of CO2 from 1750. Everything else is natural variation.”
I have posted this before, but I’ll post it again in case “Peter” hasn’t seen it. Real scientifically based estimates are reducing all the time as more data is acquired and our understanding of climate science improves.
Extrapolate the ECS and TCR trend lines out to around 2020 or slightly later.
You should consider positive feedbacks. Once temps climb too much, positive feedbacks start to play the game. That’s the big problem. If temps climb so fast positive feedbacks are stronger.
Positive feedbacks are an unproven theory. They never occurred in previous interglacials despite the increase in CO2 that occurred following temperature increases.
We are at the top of the AMO. It will drop. It will cool for 30 years.
Less reflective power of ice with melting and steam of water are very proven positive feedbacks. There are more but these two are very very proven.
“Less reflective power of ice with melting and steam of water are very proven positive feedbacks”
No, they have been hypothesised, but certainly not proven, very much the opposite in fact.
There have been many periods in the past when there have been no icecaps and when water vapour levels have been considerably higher without any evidence of positive feedbacks taking place.
The increase in atmospheric water vapour leading to increased cloud cover and raising the albedo of the Earth will certainly preclude such feedbacks.
In any case, the figures from NOAA Earth Systems Research Laboratory satellite observations indicate that contrary to the projections of the climate models, atmospheric water vapour concentration has not risen since 1948 – it appears to be decreasing, in fact.
http://c3headlines.typepad.com/.a/6a010536b58035970c01538e21c26c970b-pi
“You should consider positive feedbacks”
No, we should do nothing of the sort.
Given the variation in both global temperature and atmospheric CO2 concentration in the past, it is very clear that positive feedbacks cannot take place in the Earth’c climate at anywhere close to the current values of temperature and atmospheric CO2 concentration, should such feedbacks be possible, the Earth would have irrevocably turned into an iceball or a cinder billions of years ago.
The reasons for this are many, the effect of increase in cloud cover hence albedo as increased temperature leads to an increase in atmospheric water vapour concentration is one, another is the Stefan-Boltzmann law that states that thermal radiation increases to the fourth power of the difference in temperature.
There are in fact few or no examples of positive feedback observed in persistent natural systems because those systems would cease to exist, anyone who claims otherwise is either an alarmist exaggerating for effect or is unacquainted with the laws of physics – possibly both.
It is worth noting that the above graph appears to indicate that the Earth’s temperature oscillates between two attractors separated by a temperature difference of approximately ten degrees centigrade, and the Earth has spent most of its time at the higher of those temperatures and is currently hovering around the lower of the two, which indicates that some time in the future it is going to revert to the upper temperature of the two.
It is also noticeable that there is little or no correlation between CO2 concentration and temperature, CO2 has been many times higher than today even in an ice age.
“You should consider positive feedbacks”
No, we should do nothing of the sort.
Given the variation in both global temperature and atmospheric CO2 concentration in the past, it is very clear that positive feedbacks cannot take place in the Earth’c climate at anywhere close to the current values of temperature and atmospheric CO2 concentration, should such feedbacks be possible, the Earth would have irrevocably turned into an iceball or a cinder billions of years ago.
The reasons for this are many, the effect of increase in cloud cover hence albedo as increased temperature leads to an increase in atmospheric water vapour concentration is one, another is the Stefan-Boltzmann law that states that thermal radiation increases to the fourth power of the difference in temperature.
There are in fact few or no examples of positive feedback observed in persistent natural systems because those systems would cease to exist, anyone who claims otherwise is either an alarmist exaggerating for effect or is unacquainted with the laws of physics – possibly both.
It is worth noting that the above graph appears to indicate that the Earth’s temperature oscillates between two attractors separated by a temperature difference of approximately ten degrees centigrade, and the Earth has spent most of its time at the higher of those temperatures and is currently hovering around the lower of the two, which indicates that some time in the future it is going to revert to the upper temperature of the two.
It is also noticeable that there is little or no correlation between CO2 concentration and temperature, CO2 has been many times higher than today even in an ice age.
SH, I note that one of my posts from approx. 15 minutes ago posted via the WP application seems to have failed to appear on the site, can you check if it has disappeared into moderation?
Thanks!
Not in moderation..
It seems to have reappeared!
But thanks for looking anyway.
Physics shows us that water get hot from sun and ice reflect it, and water vapour increases hot. You only need a bit of physics to know that. You don’t need to go million years ago to know that. When there wasn’t ice on poles temps were around 10C higher than now.
“Physics shows us that water get hot from sun and ice reflect it”
Once again, as the atmospheric water vapour were to increase (which NOAA indicate it isn’t doing anyway) the condensation into clouds would raise the albedo and tend to neutralise it.
Further, you will find that as a result of the grazing angle of incidence of the Sun’s rays in the polar regions, the mount of heat absorbed by the water differs very little to that of the ice anyway.
“When there wasn’t ice on poles temps were around 10C higher than now.”
And, as the Earth is in the lowest temperature attractor, will be again, no matter what we do.
If you inspect my post containing the climate sensitivity estimates, you will note that current estimates are rapidly trending to zero, so it appears that very shortly the whole concept of anthropogenic CO2-induced global warming might well be history anyway.
Clouds and water vapour are different stuffs. Water vapour is increasing by NOAA. Clouds are increasing too, some of them have positive feedbacks and others have negative feedbacks. This is the most important matter scientifists are studing now. It seems that clouds with positive feedback are increasing. This is the big and real question in climate science now.
“Clouds and water vapour are different stuffs.”
No they aren’t. they are both water, albeit in different phases.
Clouds are what you get when the atmospheric temperature drops below the cloud point and the gaseous, invisible water vapour becomes visible, reflective water droplets.
So as the water evaporates from the surface and the air column rises and cools, at a certain altitude the temperature drops below the cloud point and it condenses, forming clouds.
“Water vapour is increasing by NOAA”
Not according to these graphs of water vapour concentration at different altitudes from NOAA it isn’t.
http://c3headlines.typepad.com/.a/6a010536b58035970c01538e21c26c970b-pi
Oh, by the way, you can read graphs, right?
In summer the angle of sun is big enough to increase hot, and also to increase water vapour.
Rubbish.
You are purely clown dancing now, you can’t even be bothered to follow links such as that to the NOAA water temperature history..
I’ve wasted enough of my time and bandwidth on you, you are clearly too scientifically illiterate to debate such a complex subject in any case.
I repeat, clouds can have positive or negative feedbacks. Water vapour is a positive feedback and is increasing in troposphere. I thought stuffs like theese were easy to understand. Now i see they are not.
“Water vapour is a positive feedback and is increasing in troposphere.”
I was right.
You can’t read graphs – or you don’t bother following links.
Either way, attempting to debate with you is a waste of time, you’re just another sad little troll.
New word for you: TROPOSPHERE. Everyday is good to learn something new!
Ok. Water vapor is not a feedback. You were right in this point. I have been reading abut the stuff. But you still wrong about ice and clouds.
Peter, it is patently obvious that you don’t have the slightest idea of what you are talking about.
Reblogged this on Climate- Science and commented:
Climate always change with or without human.