This article was originally posted on RealClearScience.
It is generally accepted as gospel truth among climate scientists and science writers that the world must immediately and drastically reduce carbon emissions in order to prevent apocalyptic climate change. Though RCS’s editorial stance toward apocalyptic climate change is one of skepticism — largely because doomsday prophets, be they the scientific or religious type, have always been wrong — we freely admit that a catastrophic outcome is a possibility and radical measures may be necessary. (At this time, however, we believe that the best policy is the gradual lowering of carbon emissions through the implementation of a carbon tax.)
Whatever combination of climate solutions the world decides to implement, a new analysis in Environmental Science & Technology reminds us that all policies bear costs and unintended consequences. In the case of greenhouse gas reductions, the unintended consequence may be an increased risk of global hunger.
While it is true that climate change itself in the long run will likely lower crop yields (and hence increase the risk of hunger), ironically the very act of responding to climate change could also increase the risk of hunger. The authors demonstrated this by combining a crop model with an economic model that predicted how climate change and climate policy conspire to affect factors such as crop yields and the cost of food, energy, and land. Using these outputs, the authors were able to compare the risk of hunger in two different scenarios: (1) The Business as Usual (BaU) scenario, in which no climate policy is enacted, and (2) Stringent Mitigation, in which drastic measures are implemented to reduce greenhouse gas emissions.
Even if no climate change occurs, a rather rosy assessment, the authors predict that 90 million people will be at risk of hunger by the year 2050. (Data not shown.) Assuming that climate change occurs and the world continues with Business as Usual, about 2 million additional people will be at risk of hunger. (See bar labeled “World” and “BaU”). This would be entirely due to a decrease in crop yields (green color). However, in the Stringent Mitigation scenario, in which crop yields only decrease slightly, about 14 million additional people will be at risk of hunger. (See bar labeled “World” and “Mitigation.”) What is going on?
Climate change policies aimed at reducing emissions may focus on growing more crops for biofuel. That would decrease the available food supply (thus, increasing food prices), as well as increase competition for farm land (which would further increase prices). Higher food prices will increase hunger, and this increase is represented by the blue color.
The biggest impact on hunger comes from mitigation costs (red bar). Replacing fossil fuels with more expensive energy sources or implementing pricey technological fixes such as carbon capture and storage will increase electricity prices. This, in turn, lowers real wages, the effects of which disproportionately impact developing countries. Those in poverty will be forced to choose between eating and keeping the lights on.
Despite their gloomy forecast, the authors conclude that some type of climate change mitigation is still necessary. Yes, this may put more people at risk of hunger compared to inaction, but doing nothing also has its own set of negative consequences, including sea level rise, ocean acidification, increasing the likelihood of extreme weather, and damaging ecosystems. In other words, we’re damned if we do, and damned if we don’t.
Source: Tomoko Hasegawa, Shinichiro Fujimori, Yonghee Shin, Akemi Tanaka, Kiyoshi Takahashi, and Toshihiko Masui. “Consequence of Climate Mitigation on the Risk of Hunger.” Environ. Sci. Technol. 49 (12): 7245–7253. Publication Date (Web): May 18, 2015. DOI: 10.1021/es5051748