Are We Headed for a ‘Grand Minimum’? (And Will It Slow Down Global Warming?)
The above graph compares global surface temperature changes (red line) and the Sun's energy that Earth receives (yellow line) in watts (units of energy) per square meter since 1880. The lighter/thinner lines show the yearly levels while the heavier/thicker lines show the 11-year average trends. Eleven-year averages are used to reduce the year-to-year natural noise in the data, making the underlying trends more obvious.
The amount of solar energy that Earth receives has followed the Sun’s natural 11-year cycle of small ups and downs with no net increase since the 1950s. Over the same period, global temperature has risen markedly. It is therefore extremely unlikely that the Sun has caused the observed global temperature warming trend over the past half-century. Credit: NASA/JPL-Caltech
As mentioned, the Sun is currently experiencing a low level of sunspot activity. Some scientists speculate that this may be the beginning of a periodic solar event called a “grand minimum,” while others say there is insufficient evidence to support that position. During a grand minimum, solar magnetism diminishes, sunspots appear infrequently and less ultraviolet radiation reaches Earth. Grand minimums can last several decades to centuries. The largest recent event happened during the “Little Ice Age” (13th to mid-19th century): the “Maunder Minimum,” an extended period of time between 1645 and 1715, when there were few sunspots.
Several studies in recent years have looked at the effects that another grand minimum might have on global surface temperatures.2 These studies have suggested that while a grand minimum might cool the planet as much as 0.3 degrees C, this would, at best, slow down (but not reverse) human-caused global warming. There would be a small decline of energy reaching Earth, and just three years of current carbon dioxide concentration growth would make up for it. In addition, the grand minimum would be modest and temporary, with global temperatures quickly rebounding once the event concluded.
Some people have linked the Maunder Minimum’s temporary cooling effect to decreased solar activity, but that change was more likely influenced by increased volcanic activity and ocean circulation shifts.
Moreover, even a prolonged “Grand Solar Minimum” or “Maunder Minimum” would only briefly and minimally offset human-caused warming.
Global Warming vs. Solar Cooling: The Showdown Begins in 2020
By Mindy Weisberger - Senior Writer, February 09, 2018
The sun may be dimming, temporarily. Don't panic; Earth is not going to freeze over. But will the resulting cooling put a dent in the global warming trend?
A periodic solar event called a "grand minimum" could overtake the sun perhaps as soon as 2020 and lasting through 2070, resulting in diminished magnetism, infrequent sunspot production and less ultraviolet (UV) radiation reaching Earth — all bringing a cooler period to the planet that may span 50 years.
The last grand-minimum event — a disruption of the sun's 11-year cycle of variable sunspot activity — happened in the mid-17th century. Known as the Maunder Minimum, it occurred between 1645 and 1715, during a longer span of time when parts of the world became so cold that the period was called the Little Ice Age, which lasted from about 1300 to 1850.
But it's unlikely that we'll see a return to the extreme cold from centuries ago, researchers reported in a new study. Since the Maunder Minimum, global average temperatures have been on the rise, driven by climate change. Though a new decades-long dip in solar radiation could slow global warming somewhat, it wouldn't be by much, the researchers' simulations demonstrated. And by the end of the incoming cooling period, temperatures would have bounced back from the temporary cooldown. ...
· Mar 7
NEW: The Heartland Institute, the right-wing climate denial group behind the so-called "Anti-Greta," laid off "more than half" its staff yesterday amid financial troubles, ex-employees told me.
2. Coal/oil/gas is mostly carbon (say around 80%) (source)
3. Burn 1 mass unit of coal generate about 2.5 mass units of CO2 (again conservative estimate)(source)
5. So we've 'unsequestered' 20% of all the carbon sequestered since at least the Cambrian period (say 500 million years ago)
6. 170 years (1850 to 2020) is 0.000034% of 500,000,000 years
The discussion revolves around:
Can you release 20% of something back into the atmosphere in 0.00017% of the time it took to take it out and not expect environmental consequences, particularly when that something is know to have impacts on climate?
(0.00017% assumes that carbon was sequestered at an even rate over the entire 500,000,000 years - probably not accurate, but moot for the purposes of this serviette calculation).
The issue isn't the mass so much as the concentration/density as a gas in the atmosphere.
Water vapor condenses and gets precipitated out of the air as rain/snow/etc. but CO2 can only condense into dry ice, which occurs at -110F, so the only practical way for CO2 to precipitate out of the atmosphere is by getting absorbed by plants/trees or surface water, but even in water, photosynthesis is required to prevent it from evaporating away.
And even when CO2 gets sequestered in plants, the plants die and/or get consumed/digested and become CO2 again, except to the extent they are part of a patch of land whose average carbon density through time is sustained.