By Brian Merchant, Source: TreeHugger

So here’s your ultra-depressing news of the day: a new Oxfam report indicates that we’re considerably underestimating the impact climate change will have on the world’s poor. Rising temperatures and extreme weather will cause food shocks that will hit the most vulnerable populations even harder than previously projected, the study says.

Here’s the crux of it:

Climate change is making extreme weather – like droughts, floods and heat waves – much more likely. As the 2012 drought in the US shows, extreme weather means extreme food prices. Our failure to slash greenhouse gas emissions presents a future of greater food price volatility, with severe consequences for the precarious lives and livelihoods of people in poverty.

This is pretty well-accepted stuff. A globally-warmed world means that it’s going to become a lot harder for farmers to grow crops in many regions, and that extreme weather events (which will occur with increasing frequency) stand to wipe them out more often.

Scientists have been warning about these ills for over a decade now, but Oxfam says we haven’t fully grasped just just how bad it’s going to be. The report claims that “the average price of staple foods such as maize could more than double in the next 20 years compared with 2010 trend prices,” primarily because of climate change. Price shocks on that scale would mean millions of starving people—it’s that simple.

Beyond that, “more frequent and extreme weather events will compound things further, creating shortages, destabilizing markets, and precipitating food price spikes which will be felt on top of the projected structural price rises.” That means more scenarios that result in people simply not being able to afford basic foodstuffs. And this isn’t far-fetched at all, either—food prices jumped this year after severe drought swept over 60% of the United States, which supplies half of the world with soybeans and is its largest corn-grower.

Imagine similar woes afflicting wheat producers in Russia, sugar cane growers in Brazil, and so on, with much greater frequency, and you can imagine how ugly food markets will get. Oxfam argues that we’ve got to reform the global food system as well as slash global greenhouse gas emissions to prevent disaster—which, obviously. How, now as forever, remains the thorniest problem we humanfolk have yet tackled.