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For many of us, the word 'agriculture' evokes bucolic images of lush fields of grain and pastures populated by peacefully grazing cows. In this light, the notion of "greening agriculture'' seems almost oxymoronic; could anything be greener than this?
Well, maybe not in terms of color, but in terms of environmental impact, agriculture has a sizable footprint. In many countries, including large areas of the high-income countries, those lush fields of grain used to be forests. And the fertilizer that keeps those fields so green is mostly nitrogen based, generating nitrous oxide, which – kilo per kilo – has an impact on global warming several hundred times that of carbon dioxide. And those cows – how to put this delicately? – have greenhouse gases coming out of both ends! (Methane emitted by livestock is over 20 times as potent a greenhouse gas as carbon dioxide.) And (surprise!) crops and livestock need water –lots of it. Agriculture accounts for around 70 percent of water use worldwide.
To become more climate smart, agriculture must reduce the environmental footprint of the sector, driven by deforestation, livestock production, and unsustainable production practices.
More so than in other regions, land-use change -- mainly deforestation and forest degradation -- has been the major contributor to carbon emissions (and other environmental damage) in Latin America. Land-use change accounts for 62 percent of total emissions in the region, versus 16 percent worldwide (in 2005 and for CO2 emissions only). Agricultural expansion remains the main cause of deforestation. Some of this is for large-scale production – for example, soybean and livestock production in Brazil. An estimated 85 percent of deforestation in Brazil is caused by the creation of new pasture land for livestock. In other areas, deforestation and forest degradation is associated with subsistence cultivation. Deforestation also threatens the region's vast biodiversity. Of the world's 10 most biodiverse countries, 5 are in Latin America: Brazil, Colombia, Ecuador, Mexico, and Peru. This list also comprises 5 of the 15 countries whose fauna are most threatened with extinction.
Reducing greenhouse gases
After land is converted to agricultural use, emissions of greenhouse gases other than carbon dioxide become important. These are mainly methane and nitrous oxide. In the 15 years from 1990 to 2005 (the last year data are available), Latin America's agricultural emissions of these two gases grew 35 percent, versus 16 percent worldwide, with most of the increase attributable to nitrous oxide. Emissions per dollar of agricultural GDP, however, declined in the region by 21 percent, relative to 15 percent worldwide, indicating that the region's growing share of world food markets has not been matched by a proportionate increase in emissions.
So agriculture is not always as environmentally benign as that bucolic scene might suggest. Yet, the huge advances in agricultural production, made possible in large part by expanding the use of fertilizers and irrigation, as well as expanding production area, are the reason that malnutrition and hunger have fallen even as the world's population has exploded. According to the FAO's World Food Summit website, in the early 1960s, food production worldwide was sufficient to provide all citizens with 2,300 calories per day. Over the next 30 years, world population more than doubled, but food production per capita increased enough to provide 2,710 calories per day by the mid-1990s – the ''Green Revolution''. Looking towards the future, it is clear that food production must continue to grow rapidly – around 80 percent (relative to 2010) by 2050, according to some recent estimates by the International Food Policy Research Institute – even while facing the threat that climate change poses for some key growing regions.
Latin America will have to play a major role in ramping up food production. Of the approximately 445.6 million hectares (ha) of land worldwide potentially suitable for sustainable expansion of cultivated area, about 28 percent is in Latin America, more than in any other region except Africa. The region's potential is even more pronounced if accessibility is factored in: the region has 36 percent of the 262.9 million ha of land suitable for expansion worldwide that is within six hours travel time to the closest market. With about one third of the 42000 cubic km in renewable water resources worldwide, Latin America is also well endowed in this resource. On a per capita basis, the region has the highest water endowment among developing regions. And Latin America has a strong comparative advantage in agriculture, as indicated by its growing share of food trade. Its advantage is especially strong in some of the specific kinds of food – particularly meats -- that will be most in demand as low-income countries climb up the development ladder. There is an opportunity here for the region to ''do well while doing good'' if it can continue to maintain and even increase its competitive position in world markets.
But to stay on its trajectory of high output growth and poverty reduction and at the same time realize its full potential to ramp up production in the face of climate change without increasing its environmental footprint, agriculture in Latin America must become greener and more ''climate smart,'' in several significant ways.
First, the most important pillar of a strategy to reduce the environmental footprint of agriculture is to preserve existing forest cover and encourage reforestation with native species where feasible. Substantial progress on this is the key to lowering the trajectory of emissions, conserving biodiversity, and reducing the loss of soil to erosion. Success will depend largely on discouraging unsustainable livestock production. Many Latin American countries have eliminated the most egregious policies that encouraged deforestation -- such as giving possession or land titles to those who "improve" forests by cutting down trees. Indeed, many have formally banned deforestation, although enforcement of such bans has been limited. Brazil, the most important country in the fight against deforestation, has developed forest-protection policies and projects to counter the rising pressure on forests at the expansion frontier and now has considerable experience in economic activity compatible with forest sustainability. Brazil's rate of deforestation has fallen by 80 percent over the past six years, as the government carved out about 150 million acres for conservation — an area roughly the size of France. Costa Rica has gone from high deforestation rates to net forest increases. Uruguay also has achieved a net increase in forest cover. Deforestation has dropped significantly in Mexico. But in many other places, rates of forest degradation appear to remain very high, although both their extent and impact remain poorly documented.
In addition to the fight against deforestation, we need to make sure that food is grown and distributed in ways that maximize the bang for buck, both environmentally and economically. Apart from reversing deforestation, other pillars of an environmentally friendly and climate smart strategy for agriculture in the region include:
- Making production systems more sustainable. One promising strategy is to increase the use of silvo-pastoral systems in livestock production, planting leguminous trees in pasture. This is being done in a project in Colombia, with results demonstrating that it raises carrying capacity per hectare (and profitability), as well as increasing forest cover.
- Making better use of information and communication technologies to increase efficiency. For example, precision agriculture combines geographic positioning systems with digital maps and crop growth and soil fertility models, allowing farmers to reduce input use. Weather information available through mobile phones helps farmers make better planting and pest management decisions.
- Reducing post-harvest losses. An estimated 7 percent of food produced in Latin America is lost or consumed by pests before reaching consumers. Improvements in logistics and infrastructure, as well as better use of ICT can help farmers make better sales decisions, meet increasingly stringent food quality standards, and reduce the waste;
- Developing more ecological inputs industries. Some of the most important ecological inputs are organic fertilizers (e.g., manure and crop residues), microbial organisms (rihzobium for nitrogen fixation; micorhizae for increasing phosphorus availability), biochar (agricultural waste converted to charcoal), organic pesticides (e.g., microbial pesticides), and predator or parasite insects used in integrated pest management programs. These may substitute for chemical inputs, often produced at high energy costs (e.g., urea) and which themselves may contribute to emissions (e.g., nitrous oxide in the case of urea). They may have overall positive effects on production systems (e.g., soil and water quality), further contributing to reducing emissions; and
- Managing water resources more efficiently, including assuring that energy plans make the best use of each country's hydro-electric potential and designing dams for dual use (energy and irrigation) wherever feasible. One reason why Latin America currently has such a green energy matrix – with only half the emissions per GDP as other middle income countries -- is its heavy reliance on hydro power , and we need to ensure that this continues.
- Maintain an open trading system. There are many reasons why an open global trading system encourages climate-friendly agricultural development, but that's a LONG story, which I've told in previous blogs!