Another one of those scares
Apparently we’re all going to starve because, you guessed it, climate change:
Experts have warned that the world’s ability to feed itself is under threat from the “chaos” of extreme weather caused by climate change.
Crop yields have increased enormously over the past few decades. But early warning signs have arrived as crop yield rates flatline, prompting warnings of efficiency hitting its limits and the impacts of climate change taking effect.
We tend to think this is unlikely. On the very simple basis that the vast majoirty of the world’s farming land is currently farmed well inside the productivity envelope. If all the world’s currently used farmland were farmed at that top level of efficiency we’d all be drowing in food rather than worrying about sea-level rise. So, we don’t place much credence on the idea to start with. But there’s more:
However, multiple projections suggest that climate change will soon have key crops plateauing, then sliding down again.
Ah, projections, eh?
The effects of climate change are predicted to reduce the yields of all of these key crops. This modelling only takes into account forecasts for climate change and income growth, and does not account for other factors that may limit this effect or boost yields, such as technological innovations or land use changes.
Oh, right, so that process that started with Chuck Townsend three centuries ago - that move from three crop rotation to four - just about to come to a shuddering halt just in time to make these projections come good, is it? We’re also not going to move crops miles north or south as temperature changes - that thing we already do as shown by such things as the Olive Belt and so on - and then there’s that income effect. They’re predicting that people will be getting richer and therefore eating a more varied diet. This isn’t, at all, a prediction about all of us on our current diets, it’s about the diets of very much richer people (yes, all predictions of climate change include the insistence that everyone gets richer this century).
And then the kicker for us:
Experts have warned that, under high-emission scenarios, future crop yields could decrease by a quarter.
But we know that the high emissions scenarios are not going to happen. That RCP 8.5. We’ve already done enough to head that one off at the pass. So this is, even given all of the above, a prediction of what could have happened if we hadn’t already done the things we have.
We’d suggest paying this no mind. Except for the fact that someone, somewhere, is going to use thhis as an excuse to deploy more of our tax money on a problem already solved. Aren’t they?
Tim Worstall