Its a very good question, one that forces you to think about why you believe what you believe and often asks you to make a prediction. One such question asked of atheists, for example, is, "What would it take for you to believe in God". Ebonmuse has answered that far more effectively than I did.
How about my views on Global Warming which have been made pretty clear on this blog? What would it take for me to change my mind on that?
This article got me thinking on that question. Why? Well because, if you go to any Global Warming Denialism site, you will see that a common thing that is claimed is that the earth has been cooling since 1998. And, if you limit you data set to only 1998 until now, you will see that this case could be made, even if you remove the 1998 peak.
What the hell? The thing is, there is not a single global warming scientist who thinks that CO2 is the only cause of temperature rise. Temperature rise is a result of a number of forcing functions, secondary forcing functions, and system parameters. Lets think of your house for a moment.
Why do you insulate your house? You insulate it to try to decouple the temperature of the inside to be as unrelated to the temperature outside of your house as possible. The better that you do this, the easier it is to control the temperature and the less energy (read as dollars) you use to make changes to the temperature inside your house.
So the more insulation you have, the less that the temperature outside your house will affect the temperature inside the house, and the more effect your wood burning stove on raising the temperature of your house. That is why investments in the insulation of your home can pay for itself in just a few years.
CO2 acts as insulation for the planet as do other green house gases. You can thank CO2 and other GHGs for our nice warm planet that has sustained all sorts of life for eons. However, unlike the insulation in your house, CO2 has hardly any insulating powers with respect to visible light. Visible light comes in through our atmosphere, much of which gets to converted to infrared light as it gets absorbed and re-emited (converted) to infrared energy. This energy, CO2 and other GHGs are good at keeping in, hence warming, just like the fireplace and your insulated house.
The planets climate is far far more complicated than this description above, but that is the basics. So what the hell has been going on since 1998?
Well 1998 was an El Nino year. For reasons I won't go into here, thats a the cause of an exceptionally warm year (apparently there are other ones too). But since then... why no continued strong rise? Well, what's been up with the number one forcing function, the sun?
We are a low trough in solar insolation. For some reason the sun was a little sluggish in getting back on track with its normal rise in irradiance. This usually comes with an increase in sunspot activity. Well apparently, we have just started to see the expected sunspot activity.
So finally we get to my prediction: We will not only see the trend in rise in temperatures, but we will, over the next 10 years, see a new record.
Its not a hard one, but at least it should shut up the silly folks who are trying to claim that global warming is over. I will completely stop believing in global warming if the trend does not go back to rising at the rate is was in the decades before 1998.
A little sidenote, when I look at the global temperature graph I showed above, its pretty amazing to me that there was almost zero cooling at all, despite some curbs on CO2 emissions in europe and the drop in solar insolation. To me that is stronger evidence for AGW.
Sadly, this is not as strong a prediction as I would like. Here is why,
If the prediction proves correct it will be the weakest cycle since a peak of 78 daily sunspots in 1928.
So since this may not be as strong a cycle as recent sun cycles, we may not see a record breaking year. But I am willing to bet that we will, since we have done virtually nothing globally to curb our CO2 and methane emissions (methane is 20 times stronger as a GHG as CO2).
Unlike other "skeptics", I will actually review my understanding of global warming and will likely change my mind about it if this doesn't happen.
