Randall Carlson

That is the window, the capture window for carbon dioxide. That capture window happens to be the same capture window as water vapor. What's happening is once you hit 50 to a hundred parts per million, the heat capturing ability of carbon dioxide is almost completely exhausted.

About the same time that the heat capture function of carbon dioxide begins to dissipate and lose its functionality of heat capture is when the pressure is now enough to drive photosynthesis. But again, if you go less than 150 parts per million, photosynthesis stops. During the late glacial maximum, carbon dioxide concentrations in the atmosphere got as low as 180 parts per million.

About the same time that the heat capture function of carbon dioxide begins to dissipate and lose its functionality of heat capture is when the pressure is now enough to drive photosynthesis. But again, if you go less than 150 parts per million, photosynthesis stops. During the late glacial maximum, carbon dioxide concentrations in the atmosphere got as low as 180 parts per million.

About the same time that the heat capture function of carbon dioxide begins to dissipate and lose its functionality of heat capture is when the pressure is now enough to drive photosynthesis. But again, if you go less than 150 parts per million, photosynthesis stops. During the late glacial maximum, carbon dioxide concentrations in the atmosphere got as low as 180 parts per million.

Now, if you look at the long term, and we can actually calculate, we can go from carbon dioxide trapped in bubbles in ice cores, but going back even farther than that, we can look at fossil leaves and study, look at the size of the stomatal apertures, right? And It gets more complicated than that, but basically in a nutshell, that's kind of what's going on.

Now, if you look at the long term, and we can actually calculate, we can go from carbon dioxide trapped in bubbles in ice cores, but going back even farther than that, we can look at fossil leaves and study, look at the size of the stomatal apertures, right? And It gets more complicated than that, but basically in a nutshell, that's kind of what's going on.

Now, if you look at the long term, and we can actually calculate, we can go from carbon dioxide trapped in bubbles in ice cores, but going back even farther than that, we can look at fossil leaves and study, look at the size of the stomatal apertures, right? And It gets more complicated than that, but basically in a nutshell, that's kind of what's going on.

But what we see is that the lowest carbon dioxide has been in the atmosphere since life appeared has been during the Pleistocene. What differentiates the Pleistocene from the previous Pliocene is that roughly two and a half million years ago, something...

But what we see is that the lowest carbon dioxide has been in the atmosphere since life appeared has been during the Pleistocene. What differentiates the Pleistocene from the previous Pliocene is that roughly two and a half million years ago, something...

But what we see is that the lowest carbon dioxide has been in the atmosphere since life appeared has been during the Pleistocene. What differentiates the Pleistocene from the previous Pliocene is that roughly two and a half million years ago, something...

caused a major shift in global climate and the planet began to this oscillation between interglacial like we're now in full glacial back and forth how many times i don't think anybody's worked that out yet the problem is is that each time you have a glaciation it pretty much obscures and erases a lot of the evidence of previous glaciations

caused a major shift in global climate and the planet began to this oscillation between interglacial like we're now in full glacial back and forth how many times i don't think anybody's worked that out yet the problem is is that each time you have a glaciation it pretty much obscures and erases a lot of the evidence of previous glaciations

caused a major shift in global climate and the planet began to this oscillation between interglacial like we're now in full glacial back and forth how many times i don't think anybody's worked that out yet the problem is is that each time you have a glaciation it pretty much obscures and erases a lot of the evidence of previous glaciations

But there's been enough evidence to show that, yeah, there've been a multiple interglacial glacial cycles, and that is what characterizes the Pleistocene, right? But if we go back to the beginning of life on earth, carbon dioxide concentrations have been up to a thousand to 2000 parts per million or more. In the long-term view, that's the norm.

But there's been enough evidence to show that, yeah, there've been a multiple interglacial glacial cycles, and that is what characterizes the Pleistocene, right? But if we go back to the beginning of life on earth, carbon dioxide concentrations have been up to a thousand to 2000 parts per million or more. In the long-term view, that's the norm.

But there's been enough evidence to show that, yeah, there've been a multiple interglacial glacial cycles, and that is what characterizes the Pleistocene, right? But if we go back to the beginning of life on earth, carbon dioxide concentrations have been up to a thousand to 2000 parts per million or more. In the long-term view, that's the norm.

Pre-industrial carbon dioxide, 280 parts per million. Go back to the early 1800s, 280 parts per million. Go back to the end of the last ice age, 180 parts per million. So during some of those episodes there, what we saw was that carbon dioxide came within a whisker of getting to the point where photosynthesis stops. If photosynthesis stops, the biosphere dies.

Pre-industrial carbon dioxide, 280 parts per million. Go back to the early 1800s, 280 parts per million. Go back to the end of the last ice age, 180 parts per million. So during some of those episodes there, what we saw was that carbon dioxide came within a whisker of getting to the point where photosynthesis stops. If photosynthesis stops, the biosphere dies.

Pre-industrial carbon dioxide, 280 parts per million. Go back to the early 1800s, 280 parts per million. Go back to the end of the last ice age, 180 parts per million. So during some of those episodes there, what we saw was that carbon dioxide came within a whisker of getting to the point where photosynthesis stops. If photosynthesis stops, the biosphere dies.

Now, depending on your perspective, if you look at the long-term perspective, you could say, well, we're actually in a carbon dioxide drought. And for most of life history, it's been double, triple, quadruple what it is now, with no apparent bad effect whatsoever. In fact, some of the times when life has been most prolific is when the carbon dioxide has been the greatest.