I’m just curious, if one looks back at least ten years ago, what predictions were climatologists making about the climate that now appear to come true? Which one’s seem to have been over- or underestimated? Which ones seem to have been totally off? and why?
Is ten years too much ? If so (i.e. if there has been some significant change in technology, reporting practices, etc.), we could perhaps say at least five…
Note that there’s a difference between a prediction and a simulation. A prediction says, “This is what’s going to happen.” A simulation says, “Assuming X, Y, and Z, you will expect to see this. If there is no X, you’ll see this. If there’s no Y, you’ll see this. If there’s no Z, you’ll see this. If there’s no X or Y them…etc.” Take for example that I shoot a cannonball along some trajectory. I use all the most state of the art equipment to calculate where it will land before launching it so that I can get it right where I want. But, in mid-flight, a missile is launched by my enemy and blows the cannonball up. Does this prove that my software was incorrect?
Climate simulators can only say that if a certain path is followed then you’ll have a particular result. But whether the world follows that course or not is highly variable. Oil prices might double a year later and emissions get reduced by half–something no one would have foreseen. A volcano might go off. The sun might start throwing off solar flares at an impressive rate.
The important question for a simulator isn’t whether it can predict the future accurately, it’s whether it can recreate the past, when you’ve seen and measured volcanic eruptions, solar flares, and CO2 emissions. If you can match the past, then your simulator is a valid simulator. Matching the future is a fool’s game.
We have a lot of members who live in Canada and Alaska I wonder if they have noticed the weather getting warmer, spring coming quicker, ice retreating etc.
Based on my reading:
CO2 levels - as predicted.
Temperature - predicted 0.2 degree Celsius rise in decade. A few years ago, the rise looked to be much larger than this, but now the prediction looks spot-on.
Sea level - as predicted, 2 to 3 cm rise in decade. (Rise might be 1 cm more if not for expansion of man-made reservoirs.)
What is often overlooked is how tiny these changes are (though they are expected to accelerate in coming decades). Only 0.2 degrees temperature and 3 cm sea rise in a decade. Since the temperature trend will be swamped by other fluctuations, one needs to look at the data through a “low-pass filter.” Glacier stability may be a good such low-pass filter. Glaciers and ice packs are indeed receding as predicted, but I didn’t try Googling for details: I’m afraid the unfortunate confusion about Himalayan glaciers would swamp the search results.