It wasn’t particularly stable; it varied between ~180 and 300 ppm:
There was natural variation, but it stayed bounded because the carbon sources had limited variation and the natural sinks had enough capacity. Now, humans are burning carbon that had been buried for hundreds of millions of years over the course of a few decades. That massively overwhelms the natural sinks and so there’s a spike.
But that does represent stability in the form of a very well-bounded semi-regular cycle associated with ice ages. Today, as your graph shows, CO2 levels are rapidly moving literally off the chart, and doing so in a timeframe that is essentially instantaneous by geological timeframes. This is not only far beyond the ability of the ecosystem to adapt, it also introduces dangerous climate instabilities.
Yeah; it represented stability in the form of Chronos’ example of a weight on a spring. If the perturbations are reasonably small, it just means you move slightly to a new equilibrium. If the perturbing force goes away, you go back to the original equilibrium.
If the perturbing force is very large, then you may exceed the yield strength of the spring. It no longer behaves elastically and the changes may be permanent, perhaps catastrophically so.
I wonder if there is a way to accurately determine optimum levels. Plants grow much faster where it is now and use water 20% more efficiently.
We’ll that’s not true. by replacing future co2 it would help in the ongoing absorption of CO2.
Realizing the op is looking for new ideas We might try bring desalinated ocean water to desert areas and plant more trees or crops.
That’s sometimes true within limits, but as a broad generalization it’s very misleading. First of all growth enhancement by CO2 fertilization becomes quickly limited by other constraining factors, most typically soil nutrients. This is a typical study based on the FACE (free air CO2 enhancement) protocols.
More importantly, while the IPCC WG2 report on impacts and adaptation does suggest that some crops in some temperature regions may see productivity improvements, these are projected to be temporary and quickly overwhelmed by negative factors like extreme weather, floods, droughts, and invasive pests, and that the overall impact of climate change on global crop production will be overwhelmingly negative.
That seems like an effort to select a time period just to prove one’s point that CO2 is spiking.
If I remember correctly, Earth started out with no oxygen in the atmosphere. It was biological activity that released oxygen into the atmosphere.
“25% (not ppm) to 50% of earth’s atmosphere was CO2” about 2.7 billion years back. Study suggests early Earth's atmosphere was rich in carbon dioxide | Earth | EarthSky
HoneyBadgerDC picked the timeframe of a million years, not me. Still, it’s not a bad choice since it’s also roughly the amount of time that humans have existed.
If we start extending our timeframes to hundreds of millions or billions of years, we start to cover all kinds of cataclysmic events, such as asteroid strikes and the Great Oxygenation Event. The latter is possibly the greatest environmental catastrophe in the history of Earth, even if it did eventually enable animal life.
Regardless, I hope humans can avoid being the cause of one of these disasters. Or, at least avoid being in the top 10 list.
Alas, it’s too late. Even without Global Warming, we’d be in the middle (and the cause) of one of the great extinction events. Global Warming just turns the dial up to 11.
I am going to lay my bets that man’s use of carbon fuels will one day be known as the great reset, Reduced carbon levels created more stress on larger organisms leading to a lot more species better equipped to survive in a not so carbon rich environment. We just might thrive even better with more carbon.
At one time, the dinosaurs migrated up and down the central North American sea from the Arctic with its lush forests to the Gulf of Mexico, before geological forces thrust the great plains above sea level. So climate is capable of a significant variation, and it’s possible, given time, new species will adapt to fill the voids we create. The question will be whether we fit into all that?
The fast uptake of CO2 suggests to me that we could see a rapid recovery (i.e. a century or two) once we stop creating excessive CO2. As the graph demonstrates, we are in the midst of a 100,000 year cycle particularly warm spell. We’re due to return to the ice ages perhaps, sometime in the next thousand years or more.
“Optimum” is tricky and possibly irrelevant vs the rate of change. Just looking at humans, we live and have built infrastructure in a wide range of climates. But changes that are faster than the lifetime of people and infrastructure are disruptive and expensive.
Exactly, this seems to be a bigger issue than the actual changes.
It’s a shame they cancelled the SCoPEx experiments on high altitude particle dispersion to block the sun. I can understand the concerns regarding geoengineering projects but how bad could a small test be?
But imagine if we came up with strips of plastic sheets orbiting the planet. When we’re done with them we could send them through outer atmosphere and let them burn up.
That guy didn’t die from falling out the skyscraper window. It was the sudden stop at the end that did him in.
One of the classic tactics of climate change deniers is the two-pronged approach of asking who is to say what the earth’s optimum temperature should be, and then adding to this the observation that a warmer climate has many potential benefits.
The simple answer to “what should the earth’s optimum temperature be?” is “one that is not changing at least 100 times faster than the global climate system can handle without completely breaking down, and one that is not changing perhaps 1000 times faster than biotic ecosystems can adapt without perishing.”
Answers like this are a huge part of the problem. We know we have a problem, we also know we can’t stop running on fossil fuels for some time yet. We are working on alternative energy sources but we also have to work on mitigation and adaptation. Why is it not ok to discuss all aspects of any issue?
So this method would involve a continually-increasing amount of carbon dioxide in the atmosphere, in exchange for a fixed amount of solar blocking. Or you increase the amount of solar blocking as needed, for an accelerating increase in the amount of carbon dioxide.
Exactly, the problem is global warming, not global warmth. Being warm or being cool, either one, we and other lifeforms can adapt to. The rapid change, though, we can’t.
It is OK. What’s not OK is to start off by saying that it’s not happening, then change to saying that it’s happening but it’s not our fault, then change to saying that it’s happening and it’s our fault but there’s nothing we can do about it anyway, then change to saying that we could do something about it but it wouldn’t be worth it, then change to saying that it’s happening and it’s because of us but it’s a good thing and so we shouldn’t do anything about it, and then change to saying that it’s not happening anyway so it’s irrelevant.
And then eventually say it’s happening, it’s not good, but it’s too late to do anything about it.
@Chronos beat me to it but you appear to have misunderstood what I was saying and the reason I said it. The IPCC Working Group 3 reports deal in their entirety precisely with the issues of mitigation. The WG 2 reports deal with climate change impacts, adaptation strategies, and key vulnerabilities. Each of those reports, which is re-issued with the latest findings roughly every five years, is essentially a meta-analysis of literally thousands of the most important and relevant scientific papers.
So yes, all those areas are absolutely being intensively researched.
The observation I made was factually correct and scientifically accurate, and was specifically addressed to the argument that one often hears from climate change deniers and “skeptics” to the effect that the earth has no fixed “ideal” temperature, so what’s wrong with a little warming – it might even be beneficial! This is a dangerously incorrect and grossly misleading argument, yet it’s been made by people like the notorious denier Richard Lindzen, now retired but formerly a notable atmospheric physicist who definitely knows better but always enjoyed being a disingenuous contrarian for fun and profit.