18
Sep
Pest Pressure to Rise Alongside Warming Climate, Underlining Need for Organic Production
(Beyond Pesticides, September 18, 2018) While climate change campaigners have long warned of increased pest pressure as a result of a warming planet, new research published in Science has begun to envisage the true extent of this expanding crisis for agriculture and crop yields. An Earth warmed by 2 degrees Celsius will see significant increases in insect metabolism and population growth, increasing global food scarcity. The study underlines the need to move towards more sustainable agricultural models that can better handle pests and other stressors brought about by climate change.
Scientists focused their models on the three staple crops that comprise over 40% of calories consumed worldwide – rice, corn, and wheat. Pest impacts were considered for a variety of scenarios, including a world warmed by 2 °C from Earth’s current global mean surface temperature. The Paris Climate Accords aims to limit warming to 1.5 °C, but with uncertainty around the U.S. pulling out of the voluntary agreement, the model produced by researchers represents a very possible scenario.
The results paint a grim picture for global food security and nutrition, with pest-related losses expected to increase by 19% for rice, 31% for corn, and 46% for wheat. The trajectory boarders on Malthusian, as these pest-related losses will come as the Food and Agriculture Organization predicts global food demand will need to rise 70% from 2007 levels by the year 2050.
“For many, many people in the world there is already a shortage of food, so it is not like we can afford to spare [more],” said study lead Prof Curtis Deutsch at the University of Washington to the Guardian. “A lot of people in the world, the most vulnerable, can’t afford to give up anything.”
Warmer temperatures act to speed up the metabolisms of most pests, increasing their need to eat. At the same time, the population growth of pests in most areas of the world is also expected to increase lock-step with warmer temperatures. The exception is tropical regions, where temperature is already ideal for pest population growth. While climate change will reverse this trend, tamping down on the pest pressure for most rice crops, further warming in subtropical areas is expected to intensify pest pressure there as temperatures reach optimal levels.
The study didn’t take into account the potential for explosive pest outbreaks, the ability of pests to spread crop diseases, or the interplay between specific pests and each crop, which could further exacerbate the issue. Even more concerning were the worst-case climate change scenarios modeled by researchers. In a world that experiences 4 °C warming, pest pressure for these three crops could increase by 40-100%, according to the models.
This data all point to an urgent need to transform agriculture. While researchers indicate that more crop rotation is necessary, farmers are likely to respond by increasing their use of toxic pesticides. However, it is clear that we cannnot continue down a path reliant on petroleum-based pesticides and fertilizers in order to feed the future world.
Organic agriculture represents a viable path forward that can successfully address stressors brought about by a warming climate and increased pest pressure. This method of farming can help sequester carbon, improve human health, boost local economies, and is essential to a sustainable future. Pests are addressed not through outside inputs, but by fostering natural, on-farm diversity of pest predators.
For more information on why organic is the right choice for the future of farming, see Beyond Pesticides’ Why Organic webpage. And take action to ensure that organic remains a healthy, sustainable, and resilient crop production system by taking action to comment to the National Organic Standards Board by October 4th, 2018.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: The Guardian, Science
