Wealhtheow’s Reviews > One Billion Hungry: Can We Feed the World? > Status Update

About 15-35% of total global water withdrawals for irrigated agriculture are unsustainable. Need to use better irrigation designs, manage and maintain the systems, use small-scale water systems and tube wells instead, maybe switch to crops that need less water.

Strategies Conway recommends as helping sustainable, environmentally friendly agricultural growth: intercropping, rotating crops, agroforestry, silvopasture, green manuring, minimum tillage before sowing, use of natural enemies/parasites/predators to control pests

To feed increased population by 2050, annual production must rise by 1% a year. Barriers: changing diets, increased livestock consumption, high fertilizer prices, run out of good quality land&water, climate change, plus donors pursue idiosyncratic development objectives instead of working together (thru UN & GAFSP)

Goulding et al 2011: Organic cultivation yields 30-40% less wheat than conventional, probably approximately the same for other crops. BUT, this could underestimate organic yields in developing countries where soils have degraded over time, in drought areas, or under subsistence conditions.

Stern Report: a rise in average global temp of 2 degrees celsius will reduce world GDP by 1%. Regional estimates are higher: 4% for Africa, 5% for India. Some countries have already started to assess costs of climate change. In Ningxia, increased frequency&intensity of sandstorms, drought, high temp from 1996-2006, cost of disasters was 150 mil a year, or 2% of their GDP.

'Global climate change has been largely driven by the activities of the industrialized countries. Yet its most severe consequences will be and, indeed, are already being felt by the developing countries. Moreover, it is the poor of those countries who, in part because of their poverty, are most vulnerable.'

Human water use exceeds annual average water replenishment. Freshwater shortage is moderate or severe in 50% of regions studied by GIWA. Large scale irrigation is part of the problem. Cheap electricity means lots of water gets pumped out, which means little groundwater and salinization of remaining water. Need to stem water demand, use irrigation systems appropriate for individual contexts.

Development of synthetic fertilizers and subsidy of fertilizers led to overfertilization, which means crop efficiency of nitrogen use has dropped 50%, high levels of nitrate in water, disrupt ecosystems (especially thru eutrophication)

~70% of world's extreme poor depend on livestock. However, rise in meat consumption in last few decades benefitted large producers, not poor farmers: DFID study of >800 projects found that livestock projects helped wealthy, but did not have a significant impact on poverty.

Observational USAID study in Egypt,Kenya,Mexico found that intake of animal source protein was the best predictor of growth, lactation, and cognitive function. In Kenya, 4 feeding interventions in malnourished schoolkids:1 gets meat, 1 milk, 1 oil, and 1 no extra food, over 21 months. all supplements increased weight gain, cognitive dvlpmnt, energy, play, leadership; meat group gained more lean body mass.