I’ve been looking into claims for concern over rising CO2 and temperatures, and this post provides reasons why the alarms are exaggerated. It involves looking into the data and how it is interpreted.
First the longer view suggests where to focus for understanding. Consider a long term temperature record such as Hadcrut4. Taking it at face value, setting aside concerns about revisions and adjustments, we can see what has been the pattern in the last 120 years following the Little Ice Age. Often the period between 1850 and 1900 is considered pre industrial since modern energy and machinery took hold later on. The graph shows that warming was not much of a factor until temperatures rose peaking in the 1940s, then cooling off into the 1970s, before ending the century with a rise matching the rate of earlier warming. Overall, the accumulated warming was 0.8C.
Then regard the record concerning CO2 concentrations in the atmosphere. It’s important to know that modern measurement of CO2 really began in 1959 with Mauna Loa observatory, coinciding with the mid-century cool period. The earlier values in the chart are reconstructed by NASA GISS from various sources and calibrated to reconcile with the modern record. It is also evident that the first 60 years saw minimal change in the values compared to the post 1959 rise after WWII ended and manufacturing was turned from military production to meet consumer needs. So again the mid-20th century appears as a change point.
It becomes interesting to look at the last 60 years of temperature and CO2 from 1959 to 2019, particularly with so much clamour about climate emergency and crisis. This graph puts together rising CO2 and temperatures for this period. Firstly note that the accumulated warming is about 0.8C after fluctuations. And remember that those decades witnessed great human flourishing and prosperity by any standard of life quality. The rise of CO2 was a monotonic steady rise with some acceleration into the 21st century.
Now let’s look at projections into the future, bearing in mind Mark Twain’s warning not to trust future predictions. No scientist knows all or most of the surprises that overturn continuity from today to tomorrow. Still, as weathermen well know, the best forecasts are built from present conditions and adding some changes going forward.
Here is a look to century end as a baseline for context. No one knows what cooling and warming periods lie ahead, but one scenario is that the next 80 years could see continued warming at the same rate as the last 60 years. That presumes that forces at play making the weather in the lifetime of many of us seniors will continue in the future. Of course factors beyond our ken may deviate from that baseline and humans will notice and adapt as they have always done. And in the back of our minds is the knowledge that we are 11,500 years into an interglacial period before the cold returns, being the greater threat to both humanity and the biosphere.
Those who believe CO2 causes warming advocate for reducing use of fossil fuels for fear of overheating, apparently discounting the need for energy should winters grow harsher. The graph shows one projection similar to that of temperature, showing the next 80 years accumulating at the same rate as the last 60. A second projection in green takes the somewhat higher rate of the last 10 years and projects it to century end. The latter trend would achieve a doubling of CO2.
What those two scenarios mean depends on how sensitive you think Global Mean Temperature is to changing CO2 concentrations. Climate models attempt to consider all relevant and significant factors and produce future scenarios for GMT. CMIP6 is the current group of models displaying a wide range of warming presumably from rising CO2. The one model closely replicating Hadcrut4 back to 1850 projects 1.8C higher GMT for a doubling of CO2 concentrations. If that held true going from 300 ppm to 600 ppm, the trend would resemble the red dashed line continuing the observed warming from the past 60 years: 0.8C up to now and another 1C the rest of the century. Of course there are other models programmed for warming 2 or 3 times the rate observed.
People who take to the streets with signs forecasting doom in 11 or 12 years have fallen victim to IPCC 450 and 430 scenarios. For years activists asserted that warming from pre industrial can be contained to 2C if CO2 concentrations peak at 450 ppm. Last year, the SR1.5 lowered the threshold to 430 ppm, thus the shortened timetable for the end of life as we know it.
For the sake of brevity, this post leaves aside many technical issues. Uncertainties about the temperature record, and about early CO2 levels, and the questions around Equilibrium CO2 Sensitivity (ECS) and Transient CO2 Sensitivity (TCS) are for another day. It should also be noted that GMT as an average hides huge variety of fluxes over the globe surface, and thus larger warming in some places such as Canada, and cooling in other places like Southeast US. Ross McKitrick pointed out that Canada has already gotten more than 1.5C of warming and it has been a great social, economic and environmental benefit.
So I want people not to panic about global warming/climate change. Should we do nothing? On the contrary, we must invest in robust infrastructure to ensure reliable affordable energy and to protect against destructive natural events. And advanced energy technologies must be developed for the future since today’s wind and solar farms will not suffice.
It is good that Greta’s demands were unheeded at the Davos gathering. Panic is not useful for making wise policies, and as you can see above, we have time to get it right.
Reblogged this on Climate Collections.
The temperature chart depicts a one-degree increase for the century. Other, unvarnished and untampered-with NOAA datasets show the reverse. On the one hand we have a mountains and molehills situation either way, and on the other a suspicion that if error bars were included both versions would lie within the limits–just as several digital voltmeters show disparate readings when clamped to a single wire. “Climate” science is as flyblown as its “Creation” or “Christian”predecessors, and not a whit less ignorant, superstitious and farcical.
This is comforting but how do we square this analysis with Tamino’s scary graph published the last day or two?
I’m really confused!
I have a suggestion for you. I have no idea how up to date you are on CO2, but if you go to the link below you’ll get a chart by chart breakdown of the importance of CO2 in our atmosphere. You can then judge for yourself if you want to be confused or not.
The World of CO2
The link below is a step-by-step history of climate and temperature. It’s a starting point to get the big picture.
he World of Climate Change
More charts will be added in the coming weeks and months.
The chart shows the past 2 thousand years, however it looks so radical since it’s only showing a temperature range from -0.5 to 0.5 °C. Added to this the chart shows the temperatures always being just below 0.0 °C and with very few spicks just above that range. Strange to say the least.
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Thanks Raymond. When I follow the link to World of Climate Change slide 5 is a repeat of sea level rise.
The charts load as follows. I had forgotten to correct the text order at the top after reordering the charts below.
* – N° 1 600 million years of global temperature change
– N° 2 Earth‘s temperature record for the last 400,000 years
– N° 3 Holocene period and average northern hemispheric temperatures
– N° 4 140 years of global mean temperature
– N° 5 120 m of sea level rise over the past 20‘000 years
Chart N° 5 is the 120 m of seal level rise. I put that at the bottom. It was originally one of the first slides. I however reordered them slightly more chronologically. However the time space for sea lever rise is 20 thousand years, which would mean it would have to be slide 4 and not 5. At the moment I’ll leave it like this and see how it developes.
* I put that chart at the top to start the series to give a really long range perspective on temperature change.
On a side note, Chart 2, is a chart people should look at. It’s hard to believe that 90% of the last 400 thousand years has been glacial periods. We’ve had very few warm periods and they are very short. Considering that the oceans drain out so much CO2 when the cool off, the downward trend of CO2 values isn’t surprising at all. This should be cause for alarm and not the rise in CO2. This will however be a hard nut to crack. Since it’s most likely we will continue to have more ice ages in the future the downward trend of CO2 is almost a certainty, right? That would be cause for concern if you ask me.
Always thankful of your feedback. Ray
Raymond, when I hit this link:
The first and last slides are both sea level. and the sequence appears as:
– N° 01 120 m of sea level rise over the past 20‘000 years.
– N° 02 Holocene period and average northern hemispheric temperatures
– N° 03 140 years of global mean temperature
– N° 04 600 million years of temperature change and atmospheric CO2
– N° 05 Earth‘s temperature record for the last 400,000 years
Raymond, OK the listing is fixed, but slide 1 is still sea level rise.
@Raymond. Thanks. I’m familiar with these or similar graphs but then I see Tamino’s hokey(sic) stick and I start to wonder – how he comes up with his scary graphs. I need his methodology explained – as Ron has done in his reply.
Vuurklip, be not confused. Tamino is transparent in his use of Mike’s trick to produce a hockey stick graph. He has spliced a high resolution modern temp record onto a paleo proxy temp record that cannot show variations less than cenntenial or even millennial scales. Read all about it here:
And as for Tamino’s suggestion of a billboard showing a temperature graph, that has been done already:
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Thanks for the link, it looked very much like the hockey stick. Ray
Notice the final image on that post footnote analyzing Marcott et al 2013. The lack of ancient variability is also a result of Monte Carlo statistical processing upon the paleo proxies.
Aah! Mike’s “nature trick”. Déjà vu all over again! Thank you!
You’re welcome, I knew that Ron could explain it better, but that he’s got a whole review on the hockey stick is a BIG ADDED BONUS!!!!!! I spent a lot of time getting my charts set correctly and when you have review so many different charts, it often gets confusing and misleading. I’m very happy that over the past few years I was able to learn a few things on the topic because of people like Ron that take the time to go through all the data. I’m just a graphic designer with a little background in the sciences from when I went to University many, many years ago. Cheers R
On a final note to this Hockey Stick topic, Richard A. Muller seems to be on the Climate Change bandwagon again, but with a sort of twist. He states that he was wrong about Climate Change, but as you listen to his videos it’s hard to follow if he’s just sitting on the fence or just not sure what he really believes. Whatever, his video showing how the data was manipulated by the IPCC is still spot on.
Cheers, it’s almost weekend and I am looking forward to it! R
New chart question.
Hi Ron, I’m looking to show in a graph on how the colder ocean regions absorb CO2 and the warms regions release CO2. The idea would to show as the colder regions expand through ice ages the absorption of CO2 increases. Considering that we’ve had 2.5 million years of glacial periods and very short interglacial periods resulting in a downward turn of CO2 levels. It’s very possible based on this continuing drop in CO2 levels that in the next couple of million years we might be below the 150 ppm level. Is this possible?
Raymond, that’s an interesting topic and I have not researched it deeply. I do think that there are at least two factors: water absorbtion/outgassing, and also ocean organisms feeding on CO2, eventually dying and adding to sediment. Here’s a link to one paper:
Here’s another on the biological pump:
Here’s one with images, esspecially Figure 9, though I don’t know what to make of it.
Click to access Foster%202008.pdf
Hi Ron thanks for the tipps, this will be the hardest chart to get right, I wonder if I can make it visually possible.
This is a real kicker
Germot Patzeit, he’s an Austrian glaciologist.
https://youtu.be/8dW5043ky3Y (sorry only in German, but there are lots of pictures and a few charts)
They’ve been researching the glaciers in Europe and have seen a number of retreats of the glaciers over the past 11700 years. It’s been as we have said warmer in the past, so much so that the tree lines are almost at the limits where they can grow. So all the screaming that the glaciers are retreating is just normal. It’s happened a few times in the past 11700 years. They’ve dug out and found tree trunks, dated them, then low and behold they go back thousands of years to when it was just as warm as now if not warmer in the region.
Cheers and have a very nice weekend!!!!! R
You too Raymond. BTW I am still not seeing the correct set of charts at World of Climate Change (#1 is a repeat of sea level #5)
Ok, will do that.
TWCG / Strange about the 1st chart and 5th chart. The first chart is 600 million years temp without CO2. I had to delete the old charts completely and reload them up. But that almost a week ago … Is there anyone else that could check this for you on another device? Wierd
Raymond, I was able to update but it was cumbersome. In Opera browser, where wordpress workspace is excellent, I could not get your links to work. In Edge browser I could get your webpage to display correctly, but could not copy the links. I could however download the five pictures onto my computer. Then back in Opera I revised the post linked to the saved files.
I don’t know why Simple Science 2 doesn’t allow linking as does Simple Science 1.
Thanks for reminding me about statistical methods- “The lack of ancient variability is also a result of Monte Carlo statistical processing upon the paleo proxies.” as it reminded me of why all those armed agents taped off the offices of some marketers and scientists a few decades ago.