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1. The global temperature has never in human history done what it's doing now. 2. Weather isn't the same as climate. They operate on way different scales and ti

1. The global temperature has never in human history done what it's doing now. 2. Weather isn't the same as climate. They operate on way different scales and timelines. Uncertainty in the one does not necessarily map to uncertainty in the other. 3. Climate change is most definitely not a solved problem. We know some big things we can do, and none of them are easy.

nDRDY 2mo ago
1. The further back we go, the less reliable the methods of estimating such properties. We only have values for a "global temperature" from the past few years or so. 2. Weather and climate are names for the same underlying nonlinear system. This system is the archetype of a chaotic system - predictions of values and corresponding locations becomes increasingly unreliable and then impossible on larger timescales. Climate modelling was the very thing that lead to our current understanding of sensitive dependence on initial conditions.
- phlakaton 2mo ago
  1. Sure we have values for earlier periods, estimated through abundant and reliable (in its own way) geologic evidence. But you don't even need to bo back further than 100 years to see how wildly our climate is whiplashing right now. 2. Yes, which is why climate scientists put lots of error bars on their predictions and document carefully the assumptions they're making. To wit, the assumption that we will continue to be as bone-headed about our impact on these systems as we have been. But it is still the case that I have little idea what the weather will be in my back yard in 3 mos but a pretty good idea of what global mean temperature we're looking at in 5 years.
OroPla 2mo ago
Shouldn't the smaller scale be a lot more easy to figure out? The larger the scale the more variables there are the harder everything becomes.
- phlakaton 2mo ago
  Nope! C.f. classical mechanics at scale vs. statistical mechanics.

nDRDY 2mo ago

1. The further back we go, the less reliable the methods of estimating such properties. We only have values for a "global temperature" from the past few years or so. 2. Weather and climate are names for the same underlying nonlinear system. This system is the archetype of a chaotic system - predictions of values and corresponding locations becomes increasingly unreliable and then impossible on larger timescales. Climate modelling was the very thing that lead to our current understanding of sensitive dependence on initial conditions.

phlakaton 2mo ago
1. Sure we have values for earlier periods, estimated through abundant and reliable (in its own way) geologic evidence. But you don't even need to bo back further than 100 years to see how wildly our climate is whiplashing right now. 2. Yes, which is why climate scientists put lots of error bars on their predictions and document carefully the assumptions they're making. To wit, the assumption that we will continue to be as bone-headed about our impact on these systems as we have been. But it is still the case that I have little idea what the weather will be in my back yard in 3 mos but a pretty good idea of what global mean temperature we're looking at in 5 years.

OroPla 2mo ago

Shouldn't the smaller scale be a lot more easy to figure out? The larger the scale the more variables there are the harder everything becomes.

phlakaton 2mo ago
Nope! C.f. classical mechanics at scale vs. statistical mechanics.