On February 14, 2023 we announced our Rebuttal Update Project. This included an ask for feedback about the added “At a glance” section in the updated basic rebuttal versions. This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a “bump” for our ask. This week features “Human fingerprints on climate change rule out natural cycles“. More will follow in the upcoming weeks. Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there.
At a glance
The passage of time reveals many things. Consider for a moment the myth in the box above. It is dated 2008 and says, “Global warming (i.e, the warming since 1977) is over.” Fifteen years on from that date and we can say, with complete confidence, “utter rubbish” (or words to that effect).
In a temperature record stretching back into the late 19th Century, the ten hottest years have all occurred since 2010. The hottest by a large margin (at the time of writing – early 2024) was 2023, with 2016 in second place. In both cases manmade global warming augmented by El Nino nudged these years into pole position. The opposite to El Nino, La Nina, is a phenomenon that cools the planet. One of the top ten, 2022, was also the warmest La Nina year on record. Starting to see a pattern here?
There are many natural cycles out there that do affect the climate. Consider the Milankovitch orbital cycles that are strong enough to trigger the switches between glacials and interglacials. These cycles operate over tens of thousands of years so their year-to-year effects are barely discernible.Yet they can cause ice-sheets to wax and wane over vast areas of the planet, especially in the Northern Hemisphere where the vast majority of landmasses currently reside. At the other end of the spectrum is the El Nino Southern Oscillation (ENSO) that most folk have heard of because it causes newsworthy weather events. Climate scientists know all about these cycles and their effects. It’s part of the job description.
Those of you who click on the myth’s link will find a lot about a cycle known as the ‘Pacific Decadal Oscillation’ (PDO). That’s not a regular cycle that turns up on time, as buses and trains ought to. But yes, it does influence climate as it has warm and cool phases, just like ENSO but in a different part of the Pacific Ocean and over longer periods. And yes, climate scientists monitor the PDO, just like everything else. The PDO is expressed as an Index: values above 0 are positive (warm) and those below 0 are negative (cool). And here’s the rub. Since autumn 2019, the PDO Index has been negative, often strongly so. Yet the planet’s temperature continues to rise unchecked.
The problem is that in climate more than one thing can happen at once. And since 1950, our CO2 emissions have surged ever-upwards and the climate is responding to that, too. In other words, human-caused global warming is now overdubbing the effects of such cycles. They used to count for a lot more than they do now.
The carbon cycle describes the way in which carbon moves around the planetary system comprising the atmosphere, the oceans, the biosphere and the solid Earth. The first and last components are where the problem lies. In burning fossil fuels, we have accessed carbon that by rights should have stayed in the solid Earth for untold millions of years. In doing so, that carbon has been dumped into the atmosphere. It represents a disturbance to the carbon cycle rarely seen in the geological record. And the planet is responding to that by heating up.
There’s only one cycle we need to worry about and that’s the carbon cycle.
Please use this form to provide feedback about this new “At a glance” section. Read a more technical version below or dig deeper via the tabs above!
Click for Further details
In case you’d like to explore more of our recently updated rebuttals, here are the links to all of them:
Myths with link to rebuttal
Short URLs
Ice age predicted in the 1970s
sks.to/1970s
It hasn’t warmed since 1998
sks.to/1998
Antarctica is gaining ice
sks.to/antarctica
CRU emails suggest conspiracy
sks.to/climategate
What evidence is there for the hockey stick
sks.to/hockey
CO2 lags temperature
sks.to/lag
Climate’s changed before
sks.to/past
It’s the sun
sks.to/sun
Temperature records are unreliable
sks.to/temp
The greenhouse effect and the 2nd law of thermodynamics
sks.to/thermo
We’re heading into an ice age
sks.to/iceage
Positives and negatives of global warming
sks.to/impacts
The 97% consensus on global warming
sks.to/consensus
Global cooling – Is global warming still happening?
sks.to/cooling
How reliable are climate models?
sks.to/model
Can animals and plants adapt to global warming?
sks.to/species
What’s the link between cosmic rays and climate change?
sks.to/cosmic
Is Al Gore’s An Inconvenient Truth accurate?
sks.to/gore
Are glaciers growing or retreating?
sks.to/glacier
Ocean acidification: global warming’s evil twin
sks.to/acid
The human fingerprint in global warming
sks.to/agw
Empirical evidence that humans are causing global warming
sks.to/evidence
How do we know more CO2 is causing warming?
sks.to/greenhouse
Explaining how the water vapor greenhouse effect works
sks.to/vapor
Is extreme weather caused by global warming?
sks.to/extreme
How substances in trace amounts can cause large effects
sks.to/trace
How much is sea level rising?
sks.to/sealevel
Is CO2 a pollutant?
sks.to/pollutant
Does cold weather disprove global warming?
sks.to/cold
Do volcanoes emit more CO2 than humans?
sks.to/volcano
How do human CO2 emissions compare to natural CO2 emissions?
sks.to/co2
Climate scientists could make more money in other careers
sks.to/money
How reliable are CO2 measurements?
sks.to/co2data
Do high levels of CO2 in the past contradict the warming effect of CO2?
sks.to/pastco2
What is the net feedback of clouds?
sks.to/cloud
Global warming vs climate change
sks.to/name
Is Mars warming?
sks.to/mars
How the IPCC is more likely to underestimate the climate response
sks.to/underestimat
How sensitive is our climate?
sks.to/sensitivity
Evidence for global warming
sks.to/warming
Has the greenhouse effect been falsified?
sks.to/falsify
Does breathing contribute to CO2 buildup in the atmosphere?
sks.to/breath
What is causing the increase in atmospheric CO2?
sks.to/CO2increase
What is methane’s contribution to global warming?
sks.to/methane
Plants cannot live on CO2 alone
sks.to/plant
Is the CO2 effect saturated?
sks.to/saturate
Greenhouse warming 100 times greater than waste heat
sks.to/waste
How will global warming affect polar bears?
sks.to/bear
The runaway greenhouse effect on Venus
sks.to/venus
What climate change is happening to other planets in the solar system?
sks.to/planets
Has Arctic sea ice returned to normal?
sks.to/arctic
Was Greenland really green in the past?
sks.to/green
Is Greenland gaining or losing ice?
sks.to/greenland
Human activity is driving retreat of Arctic sea ice
sks.to/arcticcycle
The albedo effect and global warming
sks.to/albedo
Does CO2 always correlate with temperature?
sks.to/correlate
Human fingerprints on climate change rule out natural cycles
sks.to/cycle
If you think that projects like these rebuttal updates are a good idea, please visit our support page to contribute!
