Global agriculture needs smart science and policies

Abstract

Food insecurity and climate change, the twin crises that may define the future [1] have brought agriculture back into the spotlight of international debate. In spite of the growing threats of climate change to agricultural yields and livelihoods, global agriculture must produce additional food to feed a growing population [2]. Today, more than ever before, we understand the significance that climate has for agriculture. Major weather and food price shocks are becoming the new norm – the recent droughts in the horn of Africa, Russia, Australia, and United States markedly affected food production and prices, and increased the vulnerability of the poor. Agriculture’s direct reliance on the natural resource base is a defining characteristic of the sector, consuming 70% of global freshwater and occupying 40% of global land area. Conventional forms of agricultural production are often unsustainable, pollute the environment and deplete the natural resources on which production relies over time. Low agricultural productivity is often associated with poverty, food insecurity, and nutrient depletion in Africa, where just 4% of smallholder farmers use improved seeds, the average fertilizer application is 9 kg per hectare, and only 1% of arable land is under irrigation. In Asia, inappropriate irrigation practices lead to elevated methane emissions and salinization, and high nitrogen fertilizer levels to greenhouse gas emissions. Agriculture is the world’s leading source of methane and nitrous oxide emissions, a substantial source of carbon emissions, and the principal driver behind deforestation worldwide. Some 30% of global greenhouse gas emissions are attributable to agriculture and deforestation. The growing consensus on the need for a climate-smart agriculture (CSA) emerged largely out of awareness of the sector’s negative impacts. More recently, this perspective of agriculture as a source of greenhouse gas emissions and environmental pollution has become more balanced, with a growing understanding of the environmental services the sector can provide if production is well-managed. CSA