hide captionJoao Tavares, a fourth-generation cocoa farmer in the eastern state of Bahia, Brazil, grows chocolate using a method called cabruca. His cacao trees are grown under the canopy of larger rainforest trees.
Anna Vigran, NPR
Joao Tavares, a fourth-generation cocoa farmer in the eastern state of Bahia, Brazil, grows chocolate using a method called cabruca. His cacao trees are grown under the canopy of larger rainforest trees.
hide captionCocoa pods grow directly off the trunk of a cacao tree. The seeds inside are roasted and fermented to make chocolate.
Anna Vigran, NPR
Cocoa pods grow directly off the trunk of a cacao tree. The seeds inside are roasted and fermented to make chocolate.
Anna Vigran, NPR
Will a Warmer World Have Enough Food?
Your most direct link to global warming may be the food you eat. The bounty of your local grocery store depends on natural cycles of rain and heat in far-flung parts of the world. Now those cycles are shifting and the effects on agriculture may be profound.
hide captionHoward Shapiro, chief agronomist at chocolate manufacturer Mars Inc., is working with Brazil's national chocolate research institute to make abandoned, deforested land profitable again. The experiment includes planting many cash crops, including chocolate.
Anna Vigran, NPR
Howard Shapiro, chief agronomist at chocolate manufacturer Mars Inc., is working with Brazil's national chocolate research institute to make abandoned, deforested land profitable again. The experiment includes planting many cash crops, including chocolate.
hide captionA cacao tree in a yard in eastern Brazil.
Joanne Silberner, NPR
A cacao tree in a yard in eastern Brazil.
Joanne Silberner, NPR
Many people agree that chocolate is good for the soul, and researchers are finding that chocolate can be good for the body, too. But the environment? How could chocolate help with global climate change?
The answer is found in a little piece of paradise, a patch of rainforest in eastern Brazil. Everywhere you look, something is growing. Orchids nestle in the crooks of trees. There are hundreds of shades of green, and the forest is loud with birds and insects.
Some areas have been thinned out and planted with cacao trees — the source of chocolate. The pods contain the magical beans that Aztecs counted like gold. The cultivated cacao trees grow just a bit higher than a man can reach, and rainforest trees tower over them like something out of Dr. Seuss — some round like lollipops, some flat like a plate.
And here's the climate connection. Rainforest trees and plants store massive amounts of carbon — keeping it from getting into the air as carbon dioxide.
Can Chocolate Help Save the Rainforest?
There's a lot less rainforest than there once was. There used to be 330 million acres of rainforest in eastern Brazil, called the Mata Atlantica. Settlers arrived hundreds of years ago and began destroying the forest for the wood, and to create fields for pasture and crops. Only 7 percent of the Mata Atlantica remains, and destruction is still going on. Every time a tree is burned, its stored carbon is released. As more carbon is released into the air, the planet gets warmer.
That worries Dario Ahnert, a plant expert at the State University of Santa Cruz in Eastern Brazil. He says farmers need an incentive to save the remaining forest, and he hopes chocolate will be that incentive.
Chocolate used to be a huge industry here, but in the past two decades, plant disease and low prices in the world market for cocoa beans devastated the industry. Farmers turned to other ways of making a living, including logging trees or burning the forest for farmland or pasture. When the nutrients in the soil were used up, the land was abandoned.
Ahnert wants to persuade farmers to return to chocolate farming and preserve the forest. His friend, Joao Tavares, shows it can be done.
Joao Tavares is a fourth-generation cocoa producer. Tavares, along with his brother and father, has 2,200 acres of rainforest planted with cacao trees. They grow cocoa using a method called cabruca — cutting down just a few of the tall rainforest trees, and planting the mid-height cacao trees underneath.
Inside Tavares' cabruca forest, the ground is covered in a thick layer of composting leaves. It's moist, shady and cool here in the cabruca. Football-shaped pods — striped in yellow and green and orange and brown — jut out from the trunks and branches of the cacao trees.
Tavares has worked hard to maintain, and also to restore, his little piece of the rainforest. He says that in the past 10 years, he has planted many wild trees.
"We understand that we have to preserve the cabruca," Tavares says, "even if you have less production."
He gets fewer cacao trees to the acre by planting inside the forest. But he avoids the drawbacks other farmers struggle with when they grow cacao trees on more open land.
"You have more production, but you have lots of problems," Tavares explains. "You have more disease, more insects, so we decide to preserve."
There's also an expanding market for environmentally friendly chocolate. Tavares has been able to get a premium for some of his crop.
Carbon Credits for Farmers?
Still, his friend, professor Ahnert, admits that cabruca is a tough sell: Farmers want more so-called modern approaches and quicker money. That's why Ahnert hopes that cabruca can become part of the carbon credit market. Farmers would then get money for preserving forest trees, as well as for their chocolate.
"You could increase the income, so I hope some day people that maintain this area are able to get carbon credits," Ahnert says.
The World Agroforestry Center and the chocolate manufacturer Mars Inc. are currently studying how carbon storage can be measured on cabruca-like farms, and whether a carbon credit system would help farmers — and the environment.
Reviving the Land through Chocolate
And there's an even more ambitious idea out there. Howard Shapiro, chief agronomist at Mars, hopes that chocolate could even bring back a little of the forest paradise that's been lost.
He's doing tests with local scientists at Brazil's national chocolate research institute.
"This is an area that's been planted on degraded land," Shapiro says, giving a tour of the three-acre research plot.
After the forest disappeared, the soil became hard and compact, like yellow cement. Only weeds grew in it. Shapiro and his colleagues asked local farmers what sort of plants they would like, both in the long run and while they wait for the soil to become rich enough to support cacao trees.
"What we decided to do was, we would begin with annual crops," Shapiro explains. "Corn, beans — things that have a cash crop value — melons, squashes, and begin to establish bananas for shade, then start to plant cacao."
They also planted rubber trees, and heliconium flowers. The first plants went in seven years ago. Now it's easy to grab a handful of soil. It's dark brown, moist and crumbly, like devil's food cake — with worms. But the worms are good for the soil.
"See all the little flowers on this tree?" Shapiro asks, pointing to a cacao tree. "All those little pink buds. ... It's healthy. These trees are healthy."
Shapiro wants to work out the details, but he's ready to say the project is a success. "We learned that you could take totally abandoned land, and you could restore it to profitability after about three years," he says.
So, will preserving, and even replanting, some of this forest in eastern Brazil fix the Earth's climate problem? No. But in this little corner of the world, it may help. And at least we'll have more chocolate.
Produced by Anna Vigran
Will a Warmer World Have Enough Food?
by Dan Charles
hide captionAn Indian farmer sorts through mangoes at a wholesale fruit market in Hyderabad.
Your most direct link to global warming may be the food you eat. All the bounty of your local grocery store depends on natural cycles of rain and sunlight, cool temperatures and warmth in far-flung parts of the world. Now, across the globe, those cycles are shifting and the effects are likely to be profound — not just for farmers, but possibly even for you.
How profound? A lot of people are trying to figure this out. Here, a look at some of the most important questions about how climate change will affect agriculture — and how agriculture has helped change the climate.
Will climate change make it easier or harder to grow food?
On average, it probably will be harder. It depends, though, on the crop and on the place. In the tropics, where it's hot already, even more heat will stress plants, resulting in smaller harvests. In colder latitudes, many crops will benefit from warmer temperatures. So Canada's farming areas are likely to expand and become more productive. India and much of Africa, on the other hand, probably will produce less food.
Plants also need water, of course, either from rainfall or rivers fed by melting snow. As the Earth warms up, patterns of wind and rain will shift. No one knows exactly where the water will end up or when it will arrive. But most of the big computer models predicting Earth's future climate, including those created by the Hadley Centre for Climate Change in London or NASA's Goddard Institute for Space Studies, foresee declining rainfall in the tropics. This would also depress harvests in those regions.
Finally, there's a good chance that climate change will produce more extreme weather, such as hurricanes and monsoons that can destroy crops and leave people with no food to eat.
Isn't more carbon dioxide in the air good for crops?
Yes. Carbon dioxide in the air is food for plants; it acts like fertilizer. But some plants can't take advantage of the extra carbon dioxide because their growth is limited by other factors, such as scarce water or nutrients in the soil. Predictions of future food production do include some so-called CO2 fertilization, but there is a lot of controversy about how large that effect will be.
So what's the answer? Will there be more food or less?
Most scientists don't foresee major changes in total food production during the next decade or two, as average temperatures increase by just a few degrees. On average, across the globe, the positive effects of more carbon dioxide in the atmosphere are projected to cancel out the negative effects caused by rising temperatures.
Even during this period, though, some regions will benefit and others will lose ground. Food production is projected to increase in temperate regions, such as North America and Europe. It may fall, however, in sub-Saharan Africa or India. As a result, the world will become increasingly dependent on a handful of major food exporters, such as the United States, Canada, Australia, Brazil and Argentina.
Forty or 50 years from now, as today's children reach middle age, things are likely to get worse. As temperatures continue to rise, along with levels of greenhouse gases in the atmosphere, most models show global food production falling. Many of the areas that will be most affected are those least able to purchase food from abroad. Foremost among these is Africa. According to some estimates, tens of millions of people could go hungry unless there's a major effort to help these countries adapt.
What can be done to avoid the worst effects?
Farmers can adapt in many ways, but it won't be easy, especially in the poorest parts of the world. Take one example: The soil in many parts of Africa is highly degraded. There's very little organic matter — decomposed leaves, roots and grass — left in the soil. It isn't replenished because any leftover vegetation gets harvested and used for fuel. Improving the soil would help Africa prepare for climate change by increasing harvests and also helping the soil store water. Actually accomplishing this, though, will require millions of farmers to change how they manage the land, and they would have to find alternate fuels that they can use for cooking.
Technology is also part of the solution, such as new varieties of crops that are better able to withstand heat, drought and floods; techniques for controlling new pests; and systems for using rainfall and melting snow more efficiently. But developing such technologies, and making them available to millions of farmers, will take a lot of money and time. (Read an NPR report on one example of improved seeds, a new line of rice that can survive severe flooding.)
And, of course, anything that increases the wealth of poor countries will increase their ability to buy food from abroad if domestic production falls short.
Doesn't farming release a lot of greenhouse gases?
Yes. It's estimated that farming is involved in 20 percent to 25 percent of all greenhouse gas emissions worldwide. Large amounts of carbon dioxide are released when farmers burn forests and grasslands in order to make way for fields. Farmers also burn plenty of fossil fuels — to power their tractors, harvesters and other equipment. In addition, when farmers plow their fields, it introduces oxygen into the soil, causing microbes to digest the organic carbon found in decomposed roots and leaves in the soil. This also releases carbon dioxide.
The most important fertilizer that farmers spread on their fields is nitrogen. Some of this nitrogen gets converted into nitrous oxide, a powerful greenhouse gas. And finally, rice paddies around the world produce about 100 million tons of methane, another potent greenhouse gas, each year.
Still, agriculture's emissions of greenhouse gases are holding steady, while other sources — mainly burning fossil fuels for other reasons — continue to increase. So agriculture's share of global greenhouse gas emissions declines each year. Food production is more likely to be a victim of climate change than its cause.