The estimable Robert Rohde of Berkeley Earth has an updated graph.
The man who hired him, Richard Muller, you may remember, is a PhD physicist who made a splash a few years back as a self styled climate skeptic, said a bunch of pretty inexcusable things about climate scientists, and scored a big grant from the Koch Brothers to restudy global temperature records from the ground up.
To his credit, Dr. Muller hired some smart people, did an honest job, and came up with the same answer that everyone else has for the last 50 years or so. Still no apologies to the good men and women he slandered, but at least, as you see below, he’s telling. the story straight.
Peter, I’ve just published my latest Ice Cube video…
Minimum volume this year hardly budged since last year, despite a cooler Arctic summer.
https://twitter.com/ahaveland/status/916756763889864706
Just wanted to thank you for making these Andy. It is a very good visualisation which I often link in discussions to make a clear point about ice volume as many seem too caught up in extent/area. It doesnt matter much if the ice left is very thin and brittle – an unfavourable Arctic summer and the whole thing can easy dip below the 2012 record any year now.
There is a problem with this map, per the guy who invented the Giss model and ran NOAA for a while, anything before about 1950 is mostly BS though to be fair he did not use those exact words. If I recall correctly he used the term unreliable which is science speak for BS. The number of stations increased drastically after WWII, The number of stations and the placement of those station in 1850 were a few hundred and the results cannot be relied on as nobody knows how accurate those observations were as the temperatures vary depending on what time of day you take them and how accurate your recording and instrument were. they also left out vast areas of the world. Basically you come up with a best guess for about a hundred years of the data.
We do know from studies using proxies that the little ice age was colder than today and that it has been warming for about 400 years. The temperature today is colder that it was around 4500 years ago when trees grew hundreds of miles north of the present tree line in Canada. It is colder than it was around 1000 AD as trees that old and older grew under what today is a glacier in Alaska.
This map suffers from the problem of all propaganda. It shows a slice of reality, the slice the author wants you to see, it leaves out everything else.
Most global warming up to the 1950 was mainly caused by solar variation and land use change anyway. Remember that when Charles David Keeling started logging CO2 levels in the late 1950s it was only at 310ppm, only some 20-30ppm above pre-industrial levels, so not a major change. But today its above 400ppm, which is a substantial change. Hence the effect of CO2 will only be seen clearly in the latter decades, and which we can clearly see these past 4.5 decades since 1970s.
When I see posts like this, I often ask if you have accepted that CO2 is a greenhouse gas? If not, you should look into the physics as its very easy to prove and can be demonstrated with an experiment. There are precise metrics now to how every molecule behaves with regards to energy and the vast amount of technology we have around us is depending on that physics to be right. Some people do accept CO2 as a greenhouse gas but don’t want to accept that it has such a big impact. Well that is also pure physics, and remember a 40% increase of CO2 is not a minor change, its a rather substantial planetary change.
If we look back on paleoclimate data for the last ice age we can see that when earth came out of that ice age (pushed by planetary orbit forcing then) the CO2 levels in the atmosphere grows by about 100ppm (from heating oceans and melting permafrost) – which in turn causes the planet to warm by +5C over 10000 years (the CO2 is added gradually as the orbital forcing favours heating). Considering that we have now already added another 100ppm above pre-industrial times, things are happening in a much more rapid pace with a 1C warming so far since 1970s.
We can only be glad that the amount of CO2 needs a square rise to have same effect. But even if we stopped all CO2 emissions now, the planet is nowhere near equilibrium with regards to incoming energy vs whatever is able to escape the system so we would expect warming for another 0.5C at least with the current 40% rise in CO2. Personally I highly doubt we will be able to keep below the 1.5C increase and will seriously struggle with 2C even.
You do go on and on. Unfortunately most of what you say is simply at best mistaken. Not having ten thousand pages lets look at one claim. The warming which melted off the last ice age could not have been the result of CO2 https://www.scientificamerican.com/article/ice-core-data-help-solve/ for example pins the lag at about 200 years. Other papers have the lag as long as 8000 years. Since warming seas would release CO2, CO2 increased as the seas warmed not the over way around is simplest answer to where did the CO2 come from in the absence of very large volcanic activity. That leaves the sun as the warmer. if the solar output increased a bit, say 5 percent, that would be enough to melt off the ice or dropped to cause the ice to form.
Since neither one of us has actually looked at the ice core and did the experiments ourselves, simply repeating one claim or another is pretty silly. How about using another test to measure the likelihood of the claim? In court or auditing one never accepts the claim without something else to help collaborate the claims. Google MODTRAN which you can use to estimate CO2 warming. When I did that I got 0.67F increase if the CO2 doubled from 400 ppm to 800 ppm. Since the last ice age melted off at levels far below even 400 ppm that implies a CO2 forcing a lot smaller than 0.67F. The claims CO2 forcing melted off the ice seem overblown if one throws in the medieval warm period and the little ice age low were a lot higher than that in temperature change.
The lag you are seeing in the ice cores is how the natural cycle of ice ages work. The big planetary orbital changes, described so well by Milankovitch are enough for the change in where the sun hits the surface as well as a variation in the total amount of energy. It is enough to gradually melt down the huge glaciers in the northern hemisphere, but over a span of 10000 years. As the ice disappears, it reveals carbon in the ground from whatever vegetation was there before the ice covered it. When that melts out it releases rather large amounts of carbon when it all adds up – but over thousands of years. In addition the oceans heat up, and warmer water does not hold CO2 that easily so the natural cycle will retain more of the CO2 in the atmosphere. The current planetary Milankovitch cycles are towards cooling and have been for the past 8000 years, but the planet is now experiencing rapid warming due to the high CO2 levels from fossil fuels burning.
The 100ppm when coming out of an ice age is enough to warm the planet by +5C as I mentioned before. One reason for this rather substantial warming effect is that the atmosphere during an ice age has as low CO2 as 180ppm, so another 100ppm is in fact a 55% increase. Due to how CO2 works, an increasing amount (square) of CO2 is needed for the same rate of warming.
In some ways we are in this AGW troubly mainly because the natural CO2 level on our planet is very low. If the natural level had been 1000 ppm, a 100ppm addition would be a very minor change and no cause for concern. But by burning large amounts of fossil fuels we have added by now 40% extra CO2 since pre-industrial times, and is now a force to be reckoned with. Plain physics would expect this to have a rather large planetary impact. But mainly because its happening so fast – the planet is now warming 30x times faster than when it does when coming out of an ice age.
While some species might be able to migrate to adapt, certainly not all will be able to – including humans who have built our whole civilization on in a rather stable climate these past 8000 years. Especially our cities near water level will feel the impact over the coming hundred years as they slowly submerge. The cost of relocating or even trying to build sea walls will be staggering – basically the Netherlands all over the planets coastline. The poor countries will no doubt have no choice but to let it go and some low lands taken by the sea will cause a massive global immigration crisis.
Muller’s good honest work is sufficient apology.