Biomass energy and the implications for climate and food

Abstract

Many experts have concluded that, if greenhouse gas concentrations are to be limited while the world’s energy demands are nonetheless met, biomass energy will be an indispensable resource. At the same time, climate change is expected to affect agricultural productivity adversely—and 15 percent of people in developing countries, according to the UN’s Food and Agriculture Organization, already suffer from extreme food insecurity. Authors from three countries—José R. Moreira of Brazil, Roberto Bissio of Uruguay (2014), and Ethan B. Davis and Tom L. Richard of the United States (2014)—explore how the potential climate mitigation benefits of devoting arable land to the production of biomass energy can be achieved without further undermining food security in the developing world.

Over the last three decades, the amount of land devoted to food crops worldwide has increased at a very modest rate, but food production has expanded significantly. The UN Food and Agriculture Organization expects that patterns will be similar over the coming decades: Food demand through 2050 will increase at a rate of 1.1 percent a year, but this increased demand will mainly be met through productivity gains, with only a small expansion in cropland required. If productivity gains come in below expectations, there are large amounts of land available that could be used for crop expansion (Alexandratos and Bruinsma, 2012). Availability of land is not a major obstacle to the expansion of bioenergy production.

But climate change may have a negative impact on biomass productivity (that is, on production of agricultural crops and bioenergy feedstock) due both to higher temperatures and to significant changes in water availability. Some argue that the effects could be especially severe in the developing world. Today’s temperatures in tropical areas, according to this argument, are very near the optimum for growing tropical crops, and higher temperatures would seriously harm productivity. Temperate regions, on the other hand, might actually experience higher yields along with higher temperatures (Hisas, 2011). Since much of the developing world is located in the tropics, the effect of higher temperatures would be especially severe in poorer countries. But one must tread carefully here. If average temperatures increase 2 degrees Celsius or more, it is certain that the environment will change in many ways—but predicting with accuracy how specific regions will be affected is very difficult. It is not so easy to conclude that decreases in agricultural production would be most pronounced in developing countries.

Nevertheless, if one assumes that higher average temperatures will affect aggregate biomass production negatively (and impact human activity in many other ways), the question then becomes to what extent bioenergy can mitigate climate change.

Bioenergy can be produced in good ways or bad ways. If environmentally friendly technologies are used and proper policies are in place, evidence suggests that bioenergy can significantly reduce emissions of greenhouse gases and meaningfully mitigate the negative impacts of climate change (Intergovernmental Panel on Climate Change, 2012). My colleague Sergio Pacca and I have calculated that 70 million hectares of sugarcane planted worldwide could—by 2030, when the world car fleet will amount to 1.6 billion vehicles—replace all gasoline and diesel used in cars (as long as the vehicles are of the plug-in hybrid variety; sugarcane could also generate the electricity that these hybrid vehicles would consume). A huge amount of carbon dioxide emissions could be avoided this way. The supply technologies—ethanol and bioelectricity—are already commercially available in some tropical countries, while the demand technology—plug-in hybrid vehicles—are already on the market too, though these vehicles may require some subsidies.

Some experts believe that, without heavy reliance on bioenergy, it will be impossible to keep planetary warming below 2 degrees, but that if bioenergy is used properly, and other mitigation options are also pursued, the 2 degree threshold might not be crossed (in which case climate change would cause no serious problems for food supply). Several studies have determined that, if fossil fuel use does not decline quickly enough to limit warming to 2 degrees or less, it may be necessary to combine bioenergy with carbon capture and storage in order to bring down concentrations of greenhouse gases. Under such arrangements, crops would capture carbon dioxide from the air during their growth phase. Energy would be derived from the crops (for instance by burning), and the resulting carbon dioxide would be captured and stored underground. This would achieve net reductions in greenhouse gases in the atmosphere.

Biofuels could be an important part of this approach. Biofuels made from certain feedstocks—mainly sugarcane, but also corn, properly planted palm oil, and animal fat—produce carbon emissions lower than those for gasoline and diesel over their full life cycle. Bringing carbon capture and storage into the picture might in some cases result in negative emissions. This may be the case with sugar fermentation, a process necessary for producing ethanol from sugar, starch, or even cellulosic material. The very pure carbon dioxide stream that results from sugar fermentation could be sequestered in saline aquifers or empty gas or oil reservoirs.

Poverty alleviation

I have already mentioned that bioenergy can be produced in good ways or bad ways. Part of doing things right is assessing biomass energy’s potential on a region-specific basis. In some areas, the availability of rural labor, land, water, and sunshine makes it possible to generate large amounts of bioenergy at a reasonable cost. Other regions are unsuitable for bioenergy production because one or more of these elements is missing.

In places where biomass energy production is appropriate, large-scale bioenergy projects can do a great deal to alleviate rural poverty. The poor are poor, to a significant extent, because profitable markets don’t exist where they live for selling what they can produce—food. And urban markets for their produce are often saturated and highly competitive.

Bioenergy markets are different. Urban residents, who now represent more than half the world’s population, have the economic capacity to purchase bioenergy. This market is not saturated, and it is open to the rural poor. Big bioenergy projects such as those that produce ethanol from sugarcane or biodiesel from palm oil and animal fat create many job opportunities, and give the rural poor a chance to achieve a decent standard of living as entrepreneurs or as employees of large bioenergy companies.

But biofuels in particular are not being adopted as widely as they deserve to be. Political constraints are the major reason for this, and much political opposition is motivated by a desire on the part of market incumbents—those who profit from petroleum—to protect their economic positions.

It is easy to see why biofuels elicit strong opposition from those with a stake in fossil fuels. Transportation fuels are an enormous market, and still a growing one, but the lion’s share of today’s transportation fuel comes in just two forms: gasoline and diesel. These are produced from just one feedstock: petroleum. And because cars and trucks circulate frequently among countries, fuels must be produced according to universal specifications. So transportation fuels are essentially a fungible commodity, with little to distinguish them from the customer’s perspective. For those who profit from petroleum, the possibility that biofuels might begin to displace fossil fuels must seem a pressing danger. Transportation fuel would become like electricity—a commodity that, derived from many sources and distributed across countries and regions, allows for free competition.

A transition from fossil fuels to biofuels would produce many winners, and some losers too. The losers would include not just corporations and individuals but nations as well. As in many such situations, the winners—no matter how numerous—are likely to be quiet. The losers may be few but will be extremely vocal.

Biofuels represent an excellent opportunity to manage global warming and to reduce poverty at the same time. They are easy to produce and distribute. They are ready for use right now. But political interests prevent biofuels from gaining the market penetration they deserve. Making matters worse, attention that should be paid to biofuels is going instead to shale gas, another fossil fuel that serves the interests of potential “losers.” One can only hope that discussion of these issues will open people’s minds to the merits of biofuels.