农户:气候变化已经影响作物

Scientists around the world predict that climate change will have dramatic effects on agriculture in the coming decades. So, too, will pests and pesticides, the loss of species and the need to increase food production for a growing population. Researchers at the International Agricultural Research Institute in Colombia are among those searching for solutions.

Producer Zulima Palacio recently visited the institute, and also spoke to Colombian farmers. This is her second of two reports from the South American nation.

In the tropical mountains in Colombia, long-time coffee grower Nelson Moreno recently started planting cassava, because he says he needed to use expensive chemicals to get a decent harvest of coffee. "The weather has changed too much. It is hard to live with this heat," Moreno said.

Nearby farmer Zoraida Mosquera agrees. She says hotter temperatures damage many harvests, including coffee. "At the cooperative, they buy it as the lowest quality."

Not far away, farmer Elias Claros Paz says higher temperatures are not the only problem. "We used to plant tomatoes, but we stopped because of pests. In order to get a harvest we had to spray seven and eight times with the most toxic chemicals."

Scientists say the combination of higher temperatures and single crops over extended periods increases problems with pests. Erick Fernandes, an adviser on climate change at the World Bank in Washington, says pests and the growing use of insecticides are not good for the land or for water sources. "Local observation suggests that as part of the extreme events, pest and invasive species are increasing," he said.?

At the International Center for Tropical Agriculture, or CIAT, in Cali, scientist Andy Jarvis is in charge of the climate change and policy program. He says at CIAT, scientists are working on crop improvement, mostly through genetic modifications "For example, beans are quite sensitive to heat and drought and so we have been looking at different scenarios of the types of genes that we can be putting into those crops so they can adapt to the future challenges."

But Erick Fernandes at the World Bank says not everybody likes geneticaly modified crops, and other options must be considered. "Just by management alone you can probably increase your adapted capacity of that crop, several fold," he said.

Fernandes says creating shaded areas, crop rotation and maintaining the environmental balance could greatly mitigate the effects of climate change.

Both Fernandes and Jarvis say increasing population represents the most serious challenge. "The real issue is not if we can produce more food but we have to produce 50 to 70% more food to address global population increase." Jarvis said.

And both say more needs to be done. "I think agriculture needs to assume a much higher profile in the discussions related to climate change. Just tackling forest or just tackling global warming is not going to do it unless we bring together the agricultural dimensions into that," Fernandes said.

"Every year that we don't address the issue, the issue is getting bigger and more costly to address later," Jarvis said.

The International Center for Tropical Agriculture also is conducting research in Africa and Asia and has begun a large multi-million dollar program to adapt global agriculture to climate change.