The yellow bars are interglacial periods. The larger white regions in between are glacial cycles, aka ice ages.
These cycles are driven by slow variations in the Earth's orbit.
These glacial–interglacial cycles have waxed and waned throughout the Quaternary Period (the past 2.6 million years). Since the middle Quaternary, glacial–interglacial cycles have had a frequency of about 100,000 years (Lisiecki and Raymo 2005). In the solar radiation time series, cycles of this length (known as “eccentricity”) are present but are weaker than cycles lasting about 23,000 years (which are called “precession of the equinoxes”).Here are my amateur observations from the chart.
Long-term cosmological cycles are much more important that what humans have done so far.
We are overdue for another ice age.
Current CO2 levels are high, but the biggest increases were 10-15k years ago, long before humans could have influenced the climate.
As these slow variations appear to be exceptionally important for glaciation, climate, and life on Earth, the Earth's orbit must be finely-tuned for human life.
If the long-term trends hold up, we have more to fear from cooling than warming. However, if catastrophic greenhouse gas emissions cause runaway warming, then this chart tells us nothing about the future.
I am not a climate expert, and I do not know whether greenhouse gases are a problem. They probably are. I just want to understand the physics. It seems possible to me that the Industrial Revolution put out just enough CO2 to postpone an ice age.
Roger,
ReplyDeleteStudy past levels of CO2. They have been much much higher... and yet there was no indication they drove temperature, at best, they follow it by a considerable amount, you can examine ice core sample testing and see this is so for yourself, even if it upsets folks who would have you believe otherwise (primarily because it makes them look silly). Past levels of volcanic activity have also caused far greater amounts of CO2 to be present in the earth's atmosphere, yet the world never spiraled into a greenhouse warming cycle of death, as geological evidence clearly demonstrates.
If carbon dioxide levels go below 180 ppm, plants begin to starve, become less efficient, and require more water. When you give plants higher amounts of CO2, they grow faster, photosynthecize more efficiently, and use less water to grow, which is why greenhouses will often pump in additional CO2 to increase/speed growth and maximize production.
If you would like an example of what can actually cause more CO2 in the atmosphere, consider a simple analogy: soda pop. We refrigerate soda pop so that the carbon dioxide (what makes the fizzy bubbles) stays suspended in the liquid. When you warm soda pop, the gas escapes much quicker causing it to go flat faster. The world's oceans operate much the same as soda pop, when they are warmed, they release more carbon dioxide, when they cool they release far less. This would be one good reason why carbon dioxide has never been shown to lead lead temperature historically, because it's always been an effect not a cause of temperature change.
As long as humans have been keeping records, it is clearly evident that warmer periods (like the Holocene) are times of human growth and expansion, and cooling periods (like the Little Ice Age LIA) are devastating to human life and agriculture by way of shorter growing seasons and less available land at higher latitudes for growing food.
CO2 has been vilified as a pollutant, when in fact it is a very vital trace gas necessary to healthy plant life, and thus is good for us. The primary reason driving anthropogenic global warming fear mongering is much the same as COVID 19, it can be used as a tool to scare people into being irrational, and thus easier to ply into giving up large amounts of money and control to those who pretend to be concerned and claim to be able to do something about it. Be also aware that some of the same idiots who would like you to fork over billions for their 'save the world from warming', were also trying to scare people into giving them money to 'save the world from cooling' back in the 1970s.
We do know that CO2 levels have been increasing, and that the source of the increase is the burning of fossil fuels.
ReplyDeleteRoger,
ReplyDeleteSignal to noise. What is your exact signal? What is your background noise? Yes of course every damn breath you take adds to CO2, and every sugar laden calorie your body burns contributes to heat, but (and it's a big BUT), compared to the background, how much is that specifically? What effect does human contributions make compared to that background... and what percentage is it numerically, not 'sorta alot', 'a bunch', 'UUUUGE impact', yadda yadda yadda. Vague non-numerical weasel words are not science, but speculation.
What most folks are actually responding to are computer models of warming that can't even account for clouds (as they do not know specifically how to model them) or account for solar activity (which is NOT a constant), and cosmic background activity (which potentially affects cloud formation and coverage), and many of the models represent the earth as a flat disk which for modeling purposes is far easier than modeling a spherical surface. Most of the computer models run hot, which should not surprise anyone since they often attribute any forcing they like carbon dioxide to get any agreement they are looking for.
If you wish to see behind the curtain exactly what kind of shenanigans are going on behind the curtain of climatology and climate modeling, a good place to start looking is wattsupwiththat.com, the site pokes at the nuts and bolts of climate computer modeling and outright bias.
Sad truth is, climatology is more political and monetary than scientific much of the time, to the point where statements are made regularly (such as by the esteemed IPCC) to redistribute money, power, and control, often to un-elected authorities which DO have financial conflicts of interest. When your continued funding depends upon creating a climate of fear, do you think honesty and integrity is valued?
Near 100% of physicists agree that humans add both heat and CO2 to the climate, obviously. What they DO NOT agree on is how much of an impact this contribution is to the climate as a whole, as the planet's climate is a fantastically non-linear and complex system and not fully understood. At present science is not actually certain how much CO2 is the background, as vast amounts of CO2 comes from volcanic activity, much of which is under the oceans which only cover about 70% of the planet. Volcanic activity is not constant or very predictable, this just adds further uncertainty to the modeled predictions.