Geoengineering and Brazil nuts

Today I was talking with a friend about climate change and other catastrophes we humans are creating on a planetary scale. The subject came up of finding technological solutions to get us off the hook. I have in other places argued that indeed, an industrial, technological fix seems to me to be the only realistic option for getting the atmosphere's CO2 levels back down to normal, and I have proposed socially-sustainable ways of implementing large-scale carbon sequestration. Of course we will also need other, nature-based approaches to sequestering carbon, for example massive reforestation projects such as those profiled for the northern China loess plain and in Las Gaviotas, Colombia. I've also suggested agrarian reforestation projects along these lines. Anyway, I sincerely hope that humans will someday soon find a magical fix to carbon-dioxide-caused global warming, but hope is not a sound problem-solving strategy. And despite my numerous ideas and proposals to reduce global warming in our time, I'm not too hopeful about the prospects of solving this massive problem.

At any rate, our conversation also got me thinking about so-called geoengineering. This is a neologism that refers to engineering large-scale, planet-wide processes, especially in the context of combating global warming. I've heard proposals of things like seeding the oceans with iron to encourage CO2-absorbing algal blooms, or shooting aerosols into the atmosphere to reduce the solar radiation reaching (and thus heating) our planet. Such proposals seem like lethal hubris to me, the product of minds accustomed to dealing with systems far less complex than the Earth's intricate web of relations and balances. The potential negative side effects (plummeting crop yields due to reduced sunlight, massive dead zones in the ocean, etc.) are horrid, and those side effects we can foresee are surely a mere fraction of the disasters that would actually result.

An example of a system that mankind has yet to fully control is the production of Brazil nuts. Brazil nuts grow on trees scattered throughout the Amazon rainforest. Ingenuous entrepreneurs have long dreamed of producing these valuable nuts on an industrial scale in plantations, but it has never worked. Brazil nut trees in plantations tend not to produce many or any nuts. Today we understand that this is because Brazil nuts require a complex ecological web to produce fruit. The flower of the tree is pollinated only by a certain species of bee, which depends for mating on a certain species of orchid. This epiphytic orchid, in turn, grows not on Brazil nut trees but on other intact rainforest species. So what would seem like a simple operation--plant Brazil nut trees and harvest Brazil nuts--can't work without a whole series of other considerations. Even now that we know the general ecological functioning behind Brazil nut pollination, plantations of the tree are still not productive. I imagine this is because there are other factors we don't yet understand that impede our successful manipulation of the factors we do understand. So as of today, all the Brazil nuts you buy at the store have been manually harvested from wild trees in intact forests.

Anyway, if we can't even suitably control the production of a simple nut whose ecology we more or less understand, how could we expect to manage the millions of similar systems encompassed in the entire geosphere?