In 1999, Mann, Bradley and Hughes published a reconstruction of temperatures for the past thousand years, later expanded to cover the past two thousand, based on proxy data.
"The fact that it was above its current level by more than five degrees for most of the past 250 million years and by more than ten degrees for substantial parts of the past hundred million is evidence against the more extreme versions of climate catastrophism."
I don't think this is right. It is not much of an argument unless you interpolate "and humanity lived through those 250m years just fine," and there's a problem with that.
If part of the worry surrounding AGW is that there is a tipping point or runaway effect where the Earth heats up exponentially and turns into Venus, the fact that it didn’t happen with temperature 10 degrees higher than current should make you less worried. Even at 1.2 degrees a year that gives something like 800 years before we get out of the “happened before, didn’t spiral out of control” range. That’s a lot of years to figure out how to fix things without drastically wrecking eg the economy.
That aside, there are people who speak as though an increase of five degrees would make the Earth uninhabitable. And almost everyone in the catastrophist group ignores the range of climates over which humans currently prosper, which includes lots of places more than five degrees warmer than the global average.
We know that beings not very different from us, mammals, survived just find in a hotter environment. Our civilization makes us less vulnerable, not more — they didn't have air conditioning and irrigation and ...
Every indication we have shows that significantly warmer previous climates went hand in hand with massive increases in the abundance of life. Colder periods are marked by a significant decline in life. It may not be human life, but we would need a more specific argument against humans surviving or even thriving in such conditions than "we don't know, so we should be worried."
Sure. The counter to that is, humanity has adapted itself very precisely to things as they are, so any change is actually bad. Like a Jenga tower: there's nothing inherently virtuous about the way the bricks are stacked, but change of any kind is fraught with danger.
Human adaptability is not that precise, though. It spans a range going from places like Siberia, with an average temperature around 3deg C, to places like India, with 27deg C, and in each case, the people acclimate to a window around that average that is about 35deg C in width.
Given that humans everywhere cope routinely with 35deg-C variations on an annual basis, a change of 2deg C over an entire century looks negligible, even if we try to incorporate confounders like which GMO crop is bred at which latitude.
The picture looks even more favorable when we consider that most of the rise in GAT is expected to happen in the coldest climates, where the fewest people live, and also where the most temperature-related fatalities occur.
My point was less about physiology, more that we have put our coastal cities and farmland and stuff in positions which expect current sea levels, temperatures, rainfall etc. It is great to think that what we lose in Africa and India we more than gain on the steppes and in Siberia, but you can't automatically transplant populations from there to here.
That's where the 100-year span non-problem comes in. While there are famous examples of certain families owning the same plot of land or farm or house for more than a century, most people do not. A homeowner's children move elsewhere; the owner sells that property to someone else, who often has a different use in mind for it. On this timescale, one would see humanity shifting from place to place, but any one individual tends to stay put. And over a century, there is plenty of time to do that; moreover, people will routinely shift for reasons unrelated to climate. Any factor that changes the price of real estate that is ultimately traceable to a rise in GAT ends up being one of many factors that occur anyway.
Basically we are being perfectly rational, from our own perspective, but it isn't clicking with other people. Apparently people would rather stress about global warming than.... Than what?
DF's climate stuff clicks with me. He's a libertarian. Here's big government making a bunch of openly fake claims about climate, interspersed with actual science about climate, all shot through with corrupt pork barrel politicking, government shakedowns, and controlled media. What libertarian could resist?
"The fact that it was above its current level by more than five degrees for most of the past 250 million years and by more than ten degrees for substantial parts of the past hundred million is evidence against the more extreme versions of climate catastrophism."
I don't think this is right. It is not much of an argument unless you interpolate "and humanity lived through those 250m years just fine," and there's a problem with that.
If part of the worry surrounding AGW is that there is a tipping point or runaway effect where the Earth heats up exponentially and turns into Venus, the fact that it didn’t happen with temperature 10 degrees higher than current should make you less worried. Even at 1.2 degrees a year that gives something like 800 years before we get out of the “happened before, didn’t spiral out of control” range. That’s a lot of years to figure out how to fix things without drastically wrecking eg the economy.
Fair enough, if there are people who think that is on the cards.
There are.
That aside, there are people who speak as though an increase of five degrees would make the Earth uninhabitable. And almost everyone in the catastrophist group ignores the range of climates over which humans currently prosper, which includes lots of places more than five degrees warmer than the global average.
We know that beings not very different from us, mammals, survived just find in a hotter environment. Our civilization makes us less vulnerable, not more — they didn't have air conditioning and irrigation and ...
Every indication we have shows that significantly warmer previous climates went hand in hand with massive increases in the abundance of life. Colder periods are marked by a significant decline in life. It may not be human life, but we would need a more specific argument against humans surviving or even thriving in such conditions than "we don't know, so we should be worried."
Sure. The counter to that is, humanity has adapted itself very precisely to things as they are, so any change is actually bad. Like a Jenga tower: there's nothing inherently virtuous about the way the bricks are stacked, but change of any kind is fraught with danger.
Human adaptability is not that precise, though. It spans a range going from places like Siberia, with an average temperature around 3deg C, to places like India, with 27deg C, and in each case, the people acclimate to a window around that average that is about 35deg C in width.
Given that humans everywhere cope routinely with 35deg-C variations on an annual basis, a change of 2deg C over an entire century looks negligible, even if we try to incorporate confounders like which GMO crop is bred at which latitude.
The picture looks even more favorable when we consider that most of the rise in GAT is expected to happen in the coldest climates, where the fewest people live, and also where the most temperature-related fatalities occur.
My point was less about physiology, more that we have put our coastal cities and farmland and stuff in positions which expect current sea levels, temperatures, rainfall etc. It is great to think that what we lose in Africa and India we more than gain on the steppes and in Siberia, but you can't automatically transplant populations from there to here.
That's where the 100-year span non-problem comes in. While there are famous examples of certain families owning the same plot of land or farm or house for more than a century, most people do not. A homeowner's children move elsewhere; the owner sells that property to someone else, who often has a different use in mind for it. On this timescale, one would see humanity shifting from place to place, but any one individual tends to stay put. And over a century, there is plenty of time to do that; moreover, people will routinely shift for reasons unrelated to climate. Any factor that changes the price of real estate that is ultimately traceable to a rise in GAT ends up being one of many factors that occur anyway.
Why isn't this more acceptable socially?
Watching you write about global warming is a little bit like me writing about artificial intelligence and G-d.
(Would love if you would comment on https://ishayirashashem.substack.com/p/artificial-intelligence-vs-g-d?sd=pf)
Basically we are being perfectly rational, from our own perspective, but it isn't clicking with other people. Apparently people would rather stress about global warming than.... Than what?
I read your arguments, and I find them convincing. But you've been making these arguments for a long time.
Now I can tell you from personal experience that if I made the exact same argument, I'd be laughed out of the room.
DF's climate stuff clicks with me. He's a libertarian. Here's big government making a bunch of openly fake claims about climate, interspersed with actual science about climate, all shot through with corrupt pork barrel politicking, government shakedowns, and controlled media. What libertarian could resist?