Rice Cultivation Issues - Human Impacts on Earth Systems - Reading and Research (6-8 NGSS)

Rice is a major food staple for people around the world. The United Nations Food and Agricultural Organization (FAO) estimates that more than 3 billion people depend on rice for food. Plus growing rice provides income for more than 100 million households in developing countries. Since 2000, the demand for rice has become higher than the amount of rice that so far can be grown. Additionally, as the world population grows and land and water resources shrink and global temperatures rise – these factors will combine to affect the amount of rice that can be grown in the future. Higher temperatures in rice growing regions can cause grain sterility and decrease yields. Low lying coastal rice fields are being affected by rising sea levels and tidal waves which increase soil salinity (salt levels) and decrease the areas where rice can be grown. Climate change has also brought changes in local weather patterns with unexpected droughts and floods which can be particularly bad in the low-lying areas where rice is grown. Despite the need for water in growing rice, sudden flooding can destroy a crop.

The real dilemma, however, is that growing rice actually contributes to climate change. First, some rice growers are increasing upland rice growth with slash-and-burn cultivation sending more carbon into the atmosphere, while decreasing the forested habitats (deforestation) which absorb carbon. In some regions, this is also resulting in desertification (sub-Saharan Africa), which makes land much harder to reclaim or reuse. Second, flooded rice soils give off methane emissions which has been identified  as  a contributor to global warming. It is estimated that rice fields account for as much as 10% of the total global anthropogenic (human made) methane emissions. The use of nitrogen fertilizer in rice production in some regions also contributes to nitrous oxide emissions, another greenhouse gas contributing to climate change.

How can we grow the rice people need, increase yields for a growing population, avoid clearing more natural ecosystems, while minimizing greenhouse gas emissions?

Do some research on new rice growing techniques that may help monitor and minimize these human impacts on the environment.