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When have the predictions of experts been wrong? The consensus about global warming in the scientific community has been hitting it on the nose for decades. If

by Joeri 7y ago

When have the predictions of experts been wrong? The consensus about global warming in the scientific community has been hitting it on the nose for decades. If anything, they’ve underestimated how rapid change would be. Their advice has also been largely ignored by governments. If we had actually let experts dictate policy back in the 90’s when the consensus was established, global warming would be solved by now.

pdonis 7y ago
> The consensus about global warming in the scientific community has been hitting it on the nose for decades. Surely you jest. The actual data on global average temperature has been below the low end of the 95% confidence interval of the model predictions for some time now. The model predictions were always high, but now they're so high that by the usual standards of science, they are falsified.
- breakyerself 7y ago
  The planet is about 1C above baseline temps. Which is pretty much where the models predicted. Some a bit above and some a bit below, but not way off as you say. When I've seen people trot out this argument it's usually based on a dishonest reading of the models. Using model runs based on much higher emissions scenarios than what actually occurred.
  - pdonis 7y ago
    > The planet is about 1C above baseline temps. Which is pretty much where the models predicted. Sorry, but the fact is, as I said, that the actual temperature has been below the 95% confidence interval of the models for some time now. It is not "pretty much where the models predicted". Whether it's "about 1C above baseline temps" depends on where you pick the baseline, and there are at least as many choices of baseline as there are climate scientists. > Using model runs based on much higher emissions scenarios than what actually occurred. Sorry, but there are no model runs based on much higher emissions than what actually occurred. In fact it's the opposite: the actual emissions scenario that has happened is about the same as the worst case (highest) of the three classes of models (the "business as usual" models that assumed that no effort would be made to curb emissions). The only reason the actual emissions are a bit lower than that worst case model class, instead of as high or higher, is that the US shift to natural gas over the past 10 or 15 years cut US emissions almost in half. But actual emissions are significantly higher than the middle of the three model classes (the one that assumed some emissions cuts would be made), and much higher than the lowest of the three model classes (the one that assumed drastic emissions cuts would be made). So two out of the three classes of model runs were based on emissions significantly lower than what actually occurred. And yet temperatures, as I said, are lower than the low end of the 95% confidence interval. And in fact, the disparity between the models and the data is even worse than what I just said, because the 95% confidence interval that always gets quoted is based on all three of the model sets. Which makes no sense at all, because two of those model sets were based on emissions scenarios different from what actually occurred, so they're irrelevant when comparing model predictions to actual data. In fact, the only one of the three model sets that should be used to compute the 95% confidence interval is the worst case one (the highest of the three), and when you use that confidence interval the gap between the low end of the interval and the actual data is even wider (and the actual data went outside the low end of the interval even earlier).
pdonis 7y ago
> When have the predictions of experts been wrong? And just to give some other examples besides the climate model predictions of warming: Experts predicted that global cooling would lead to catastrophe in the 1970s. Experts predicted there would be mass famine and a world population crash by the early 1980s. Experts predicted that resource prices would skyrocket by the 1990s. Experts predicted that we would be out of oil (not oil prices rising, but literally out, as in no more, wells all dry) by the turn of the millennium. Experts predicted in the late 1980s that we had only 10 years to stop emitting CO2 or civilization would be destroyed. (Sound familiar?) Except in areas where controlled experiments can be done, experts have a terrible track record of prediction. That's because in areas where controlled experiments cannot be done, the process of accumulating reliable knowledge is very, very slow. So it's not that the experts could have done better; they couldn't. Nobody could. But nobody wants to hear that we simply lack good predictive ability on a global scale in areas in which people have strong public policy convictions. People would rather have experts make unrealiable predictions, than have them truthfully say they just don't have the ability to predict.
- Joeri 7y ago
  Individual scientists get predictions wrong, consensus generally doesn’t since the dawn of modern science. If you research it you’ll see for example that global cooling was a minority view and the consensus at the time was warming. Even the very first IPCC report from 1990 proved accurate in its predictions decades later because it was a consensus work. Climate predictions from the IPCC reports are accurate. There are decades of evidence.
  - pdonis 7y ago
    > Individual scientists get predictions wrong, consensus generally doesn’t since the dawn of modern science. Not if "consensus" is defined so that the current climate change alarmism counts as "consensus". If the consensus is based on repeated controlled experiments that verify predictions to high accuracy, then yes, that kind of consensus generally doesn't make wrong predictions. In fact such a consensus almost never makes wrong predictions. But such a consensus is also rare in science, because it's very hard to make enough repeated controlled experiments to high enough accuracy to justify it. > global cooling was a minority view and the consensus at the time was warming. In the 1970s? No, it wasn't. The experts I mentioned were scientists. > Even the very first IPCC report from 1990 proved accurate in its predictions decades later I have no idea where you're getting that from. Those predictions are among the ones that are now falsified by the data. Even the IPCC itself implicitly admitted that in the AR5, by no longer claiming that its projections of climate change up to 2100 were based on climate models; they now claim those projects are based on "expert opinion", without specifying how that expert opinion was arrived at.

by Joeri 7y ago

pdonis 7y ago

> The consensus about global warming in the scientific community has been hitting it on the nose for decades. Surely you jest. The actual data on global average temperature has been below the low end of the 95% confidence interval of the model predictions for some time now. The model predictions were always high, but now they're so high that by the usual standards of science, they are falsified.

breakyerself 7y ago
The planet is about 1C above baseline temps. Which is pretty much where the models predicted. Some a bit above and some a bit below, but not way off as you say. When I've seen people trot out this argument it's usually based on a dishonest reading of the models. Using model runs based on much higher emissions scenarios than what actually occurred.
- pdonis 7y ago
  > The planet is about 1C above baseline temps. Which is pretty much where the models predicted. Sorry, but the fact is, as I said, that the actual temperature has been below the 95% confidence interval of the models for some time now. It is not "pretty much where the models predicted". Whether it's "about 1C above baseline temps" depends on where you pick the baseline, and there are at least as many choices of baseline as there are climate scientists. > Using model runs based on much higher emissions scenarios than what actually occurred. Sorry, but there are no model runs based on much higher emissions than what actually occurred. In fact it's the opposite: the actual emissions scenario that has happened is about the same as the worst case (highest) of the three classes of models (the "business as usual" models that assumed that no effort would be made to curb emissions). The only reason the actual emissions are a bit lower than that worst case model class, instead of as high or higher, is that the US shift to natural gas over the past 10 or 15 years cut US emissions almost in half. But actual emissions are significantly higher than the middle of the three model classes (the one that assumed some emissions cuts would be made), and much higher than the lowest of the three model classes (the one that assumed drastic emissions cuts would be made). So two out of the three classes of model runs were based on emissions significantly lower than what actually occurred. And yet temperatures, as I said, are lower than the low end of the 95% confidence interval. And in fact, the disparity between the models and the data is even worse than what I just said, because the 95% confidence interval that always gets quoted is based on all three of the model sets. Which makes no sense at all, because two of those model sets were based on emissions scenarios different from what actually occurred, so they're irrelevant when comparing model predictions to actual data. In fact, the only one of the three model sets that should be used to compute the 95% confidence interval is the worst case one (the highest of the three), and when you use that confidence interval the gap between the low end of the interval and the actual data is even wider (and the actual data went outside the low end of the interval even earlier).

pdonis 7y ago

> When have the predictions of experts been wrong? And just to give some other examples besides the climate model predictions of warming: Experts predicted that global cooling would lead to catastrophe in the 1970s. Experts predicted there would be mass famine and a world population crash by the early 1980s. Experts predicted that resource prices would skyrocket by the 1990s. Experts predicted that we would be out of oil (not oil prices rising, but literally out, as in no more, wells all dry) by the turn of the millennium. Experts predicted in the late 1980s that we had only 10 years to stop emitting CO2 or civilization would be destroyed. (Sound familiar?) Except in areas where controlled experiments can be done, experts have a terrible track record of prediction. That's because in areas where controlled experiments cannot be done, the process of accumulating reliable knowledge is very, very slow. So it's not that the experts could have done better; they couldn't. Nobody could. But nobody wants to hear that we simply lack good predictive ability on a global scale in areas in which people have strong public policy convictions. People would rather have experts make unrealiable predictions, than have them truthfully say they just don't have the ability to predict.

Joeri 7y ago
Individual scientists get predictions wrong, consensus generally doesn’t since the dawn of modern science. If you research it you’ll see for example that global cooling was a minority view and the consensus at the time was warming. Even the very first IPCC report from 1990 proved accurate in its predictions decades later because it was a consensus work. Climate predictions from the IPCC reports are accurate. There are decades of evidence.
- pdonis 7y ago
  > Individual scientists get predictions wrong, consensus generally doesn’t since the dawn of modern science. Not if "consensus" is defined so that the current climate change alarmism counts as "consensus". If the consensus is based on repeated controlled experiments that verify predictions to high accuracy, then yes, that kind of consensus generally doesn't make wrong predictions. In fact such a consensus almost never makes wrong predictions. But such a consensus is also rare in science, because it's very hard to make enough repeated controlled experiments to high enough accuracy to justify it. > global cooling was a minority view and the consensus at the time was warming. In the 1970s? No, it wasn't. The experts I mentioned were scientists. > Even the very first IPCC report from 1990 proved accurate in its predictions decades later I have no idea where you're getting that from. Those predictions are among the ones that are now falsified by the data. Even the IPCC itself implicitly admitted that in the AR5, by no longer claiming that its projections of climate change up to 2100 were based on climate models; they now claim those projects are based on "expert opinion", without specifying how that expert opinion was arrived at.