Is there enough food produced annually to provide a subsistence diet for the entire population of Earth? (Bonus points for data involving shelter, clothing or education.)
This question was inspired by this question.
I would think so. According to the FAO, 152kg of food per capita were produced globally in 2007/20081, which equates to approximately 500gr of food per day - not a lot, but you could conceivably survive.
I don't think there is any need for research here, certainly yes (although most people would have a minimum of 1 set of clothes).
This year about 500 billion US$ will be spend on education worldwide2 - whereas, if we used our military budget3 for education we could add $1.61 trillion4 per year. I think this should cover more than enough the 36 million children in Africa that may not have access to education5.
This question pops up all the time, fueled by the ever repeating Malthusian fables about impending disaster due to mass starvation unless the population of the planet is brought down to a fraction of what it currently is.
As is, there's no large scale lack of nutrition on the planet today (local catastrophes excluded, like people caught up temporarilly in natural disasters or wars). Thus, the planet is more than capable of feeding its current population (those areas where there is lack of food experience that because the local population doesn't put in the effort needed to produce it, not because that effort would be futile but because they don't think it a priority in comparison with (usually) killing each other). In fact, given the massive overproduction of foodstuff in parts of the world (especially the EU and US where agricultural policies cause farmers and processing industry to destroy produce rather than put it on the market so as not to cause food prices to collaps, and get paid for that by government subsidies) the world can feed a lot more people than exist on it today, even without resorting to more efficient ways of production (though those would certainly relieve a lot of people in especially Africa and Asia of backbreaking work as they're still tilling their fields in what are essentially medieval fashion).
That's for food. Clothing, as I commented earlier, is a non-essential item for the majority of the world's population when it comes to physical survival and even physical comfort. It can therefore essentially be excluded when calculating whether the earth is self supporting as obviously it is (I don't know of any large population group that involuntarilly goes without clothing when not forced to by other people rather than a real lack of it that they could be supplied with). Given that most people have access to far more clothing than they'll ever wear (especially in northern areas) only strengthens that conclusion.
Shelter is a bit more tricky, but has more or less the same answer. While there are people who are homeless, in some areas even large groups that are homeless, these people aren't homeless (permanently, sometimes temporarilly due to natural disasters) because of lack of resources but either because of economic reasons (they were evicted because they didn't pay rent or mortgage for example), out of choice (some people choose a life on the street), or because of being forced out of their homes by other humans for political or religious reasons (like the Cops in Egypt who're essentially being driven out of the country because of their religion right now).
Education is overrated. In large parts of the world education is learning to farm the land of your father, or to perform a trade or craft. That's all that's needed to survive, and all people get it from their parents where no schools are available. Thus education has been taken care of. If you're talking about organised schooling, there's more than enough resources available for that as well. Where it's not offered (or of poor quality) despite this it's because those resources are either wasted (EU, US, etc. are prime examples of massive waste of educational resources) or diverted to other things (Africa, parts of Asia, where often funding and resources earmarked for education end up in some bureaucrat's or dictator's Swiss bank account).