Because you can predict that a slot machine will be a net profit maker for a casino without being able to predict the result of the next pull of the lever.
Of course climate models are continually updated as technology and data improves (as are the models used in structural engineering). That is how science works. Historically, though, the mainstream (IPCC) models have actually performed quite well.
Precipitation forecasts are usually accurate several days out and temperature forecasts are good a week or two out, in my experience. If I want to know if it's going to rain on Saturday I check the weather on Thursday and it's usually right. When there's a big storm comin', a local meteorologist does rolling updates with the latest data and it usually gives a consistent but evolving picture that matches up with what actually happens.
Are people disappointed by this? What are you wanting out of your weathermen that you're not getting?
I know the weatherman used to be a joke, back before satellites and computers, but I swear the cliche only survives as part of climate change denialism.
The overwhelming consensus of experts is that its going to have an enormous impact. It's still worth studying when, how and where its effects will materialize first but that does not excuse inaction.
How soon? Al Gore's "An Inconvenient Truth" predicted apocalyptic consequences in as few as 10 years. 10 years later and it turns out the documentary had tons of erroneous assumptions. Oops.
> That's akin to demanding that all engineers accurately predict which piece of the roof will collapse first, where the pieces will hit the floor, how many pieces it will break up into and on which date.
If your model has poor predictive power, it's not a complete model. Engineers can accurately predict lots of things using standard models - for example whether a building will be able to withstand shear wind forces. Climate science cannot predict anything except "it will be disastrous with apocalyptic proportions at some non-deterministic point in the future" How is that a useful prediction beyond generating hype?
In a couple of lifetimes, which is still too soon, as reversing the trend will likely take far more effort. For a graphic description of how far we're venturing out of what we're used to as a species, see https://xkcd.com/1732/
> If your model has poor predictive power, it's not a complete model - for example whether a building will be able to withstand shear wind forces.
To continue with the analogy, we know the building can't withstand shear wind forces. We just don't know exactly how and where the pieces will land.
In the meantime, other factors will contribute to our downfall much faster than climate change ever could such as increasing societal divisiveness over politics, decline in nuclear families as the basic societal unit, selfishness, and abandonment of religion.
What evidence are you basing that on?
A new problem is discovered (i.e. the earth can't sustain the current birth rate forever). The problem is hyped up[1] in an effort to find a solution (abortions -> Zero Population Growth[2]). Many in the science community buy into the hype, crunch numbers, and make dire predictions. Public policies in the 70s change in response to this evidence. ZP deniers are shamed for having large families and rejecting scientific consensus. Decades pass and the predictions don't happen. People start examining the evidence with more scrutiny and with observed data in hand retroactively debunk a lot of the assumptions made. The hype dies and everyone forgets it ever happened. So I'm sorry if I don't instantly drop everything to make the hype of the day my top priority, but a lot of hyped problems don't last more than a few decades. If climate change is still being seriously discussed in 2036 (30 years after "An Inconvenient Truth" was published) maybe I'll take it a little more seriously.
https://www.nature.com/nclimate/journal/v7/n 3/full/nclimate3224.html?WT.feed_name=subjects_climate-sciences
Climate models are actually better than meteorological models, but they predict things decades out.
The analogy is that weather is extremely complicated, so much so that meteorologists struggle to predict what will happen in the next 12 hours. If climate is an order of magnitude more complicated than weather, why should the predictions suddenly be much more accurate? My local meteorologists get the prediction right maybe 70% of the time. You're telling me the apocalyptic climate predictions approach 100% accuracy and that I have no room for skepticism?
For the same reason a doctor can't predict if an individual patient will have a heart attack, but a public health researcher can accurately predict the overall rate of heart attacks in a population.
Forecasting weather is trying to predict a single event. That is by definition harder than predicting a trend of averages.
Why is it okay to be skeptical of what meteorologists are predicting, but not okay to be skeptical of what climate scientists are predicting?
It's one thing to be skeptical of sciences that have stood the test of time like civil engineering and quite another to be skeptical of climate science, whose models are being updated annually in response to the discovery of new variables.
Note: I am not saying we should be climate change deniers, only that we should not blindly accept apocalyptic predictions as the gospel truth of what is going to happen to the planet if we fail to mitigate CO2.