|
Ok, so here's the thing about all this that often gets lost when talking about whether or not projections are accurate.
The amount of CO2 in the atmosphere IS trapping heat in our planet. First of all, it's physically impossible for it to do otherwise.
Second, the outer atmosphere is cooling, which means less heat is getting to it, and we KNOW that the sun hasn't dimmed that much - if it had, we'd ALL be feeling the effects.
From the beginning, we've known that the warming wouldn't progress in a steady line year to year or decade to decade to decade. We HAVE had a progression in which every decade has been warmer than the last, but there's no guarantee that we won't have a decade that cools for a bit, before going back up.
The physics of the situation remains the same - greenhouse gasses trap heat, more greenhouse gasses mean more heat.
The effects of more heat are also pretty straightforward.
As to whether or not drought has had an effect on food production, the 2010 drought was why Russia halted all grain exports.
Maybe there WAS a decline in productivity in the 1990's, but you know what? That doesn't change the fact that when we have a drought productivity goes down. Fast.
As has been mentioned in this very discussion, the effects of climate change don't happen overnight. The paleocene-eocene thermal maximum, which was enough of an event to be visible in the geological record, took 20,000 years to go through the whole warming, with a 10,000 year period for doubling CO2.
We're on track to double CO2 in a total of around 400 or 500 years, with warming continuing after that.
When you get into the specifics of what will or won't happen, there IS a lot that is unknown, but we DO know what happens when you raise CO2 levels (warming), and we DO know that unless there's some massive factor that nobody has thought of, that warming will continue as long as CO2 levels keep rising, and then for a while after they stabilize.
If the paper showing no significant change in drought patterns is right, then that's interesting, and worth looking it, but we haven't warmed all that much yet - we're right at the beginning of the warming - and our best understanding of how things work (which has accurately predicted a number of factors like the faster warming in the arctic, and the faster rise in average NIGHT TIME temperatures, and the melting of ice, and the changes to ecosystems, and the cooling of the outer atmosphere) indicates that drought and flood cycles will start to get more intense. Nothing has come along to indicate that that's not going to happen, or that something else IS going to happen.
|