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The agriculture issue of climate change

Tamara Scully for Progressive Dairyman Published on 11 March 2016
Agriculture issue of climate change

Climate change is real. It has happened, it is happening, and it will continue to happen. It is impacted by agricultural practices, and it impacts agricultural practices.

Farmers will have to adapt, both to minimize their contribution to the problem and to manage new situations – changes in temperature, rainfall, growing seasons, disease pressures – caused by climate change.



But farmers won’t have to figure it out on their own.

The USDA has plans to “work with farmers on both the mitigation and adaptation” aspects to solve the problem, said William Hohenstein, director, Climate Change Program Office, USDA.

Climate and agriculture

Each of the last four decades has been warmer than the last, and the warmest years on record have all occurred in the past decade. The goal for the U.S. overall is to reduce GHG below 2005 levels by 2025, representing about a 27 percent decrease in emissions, Hohenstein said.

Agriculture issue of climate change

It is “difficult to pin any one event to climate change,” Hohenstein said, but the evidence is undisputable. “It’s all connected to the buildup of greenhouse gas (GHG) in the atmosphere.”


As an industry, agriculture is responsible for 15 percent of these GHG emissions worldwide. In the U.S., only 9 percent of GHG emissions originate with animal agriculture. But the emissions caused by agriculture in the U.S. have increased 17 percent since 1990. Methane is the primary GHG attributed to agriculture.

The rate of climate change has been accelerating. Increasing temperatures, wetter springs in the Northeast and Midwest, and more extreme weather events such as heat waves or violent storms will be ongoing issues.

Simultaneously, the world’s population and wealth are increasing, and the demand for agricultural products, including meat, will require an increase in production to meet the demand.

“Across the board, you can see farmers changing production practices ... reacting to what they are seeing on the ground,” Hohenstein said. “Reactive adaptation is not going to work. Farmers are going to need to be more proactive. There are a lot of things we can do that make economic sense, and practical sense, for farmers.”

Farmers need to be proactive, both to decrease their contribution to the problem and to adapt their management strategies to changes in climate. Managing the ruminant diet, manure management and decreasing farm fuel and energy use are approaches to take to decrease GHG emissions.

On-farm impacts and adaptations to climate change

Livestock are vulnerable to climate change. Animal stress from heat and humidity will cause decreased growth, reproductive concerns and production issues. Increasing disease and pest pressures will occur as changes in climate cause diseases to emerge in regions previously not in their range. Intensification of frequency or duration of illnesses is anticipated.


The quality and quantity of feed available will both decrease. The cost of production will increase.

In order to mitigate these effects, farmers will need to be prepared with a multifaceted approach.

Breeds and types of animals raised, changes in feed types and ingredients to meet their nutritional needs, adaptations to crop planting dates, utilization of different crop varieties, engineering adaptations such as the implementation of adaptive cooling techniques or simply providing increased shade and an unprecedented focus on soil health are key aspects of adaptation.

“Good conservation practices really help build resilience,” he said. Crop insurance will be a focus as there is “a need to have a safety net for farmers when things are critical.”

In the 2012 drought, no-till practices and increasing soil organic matter were instrumental in increasing water retention in the soils. But they were not enough. Water storage and recycling will be important.

Plant genetics, such as breeding for better root system structure, will be important. Water management will require increased irrigation efficiencies. In wet areas, increased use of tile drainage will be needed.

Reducing agricultural GHG

Ruminant enteric fermentation can be improved. Further research into rumen bacteria and function is needed. Implementing dietary strategies to decrease GHG emissions associated with ruminant animals will be warranted.

Manure management will be another large piece of the equation. Solid-liquid manure separation and covering anaerobic lagoons to trap methane emissions are both management techniques that can be readily implemented. Increasing fuel and energy efficiency on the farm is also needed.

Anaerobic manure digesters can play an important role in manure management as well as renewable energy generation.

There is debate about the intensification of production required to meet the needs of a growing population, Hohenstein said. The intensification of animal agriculture could result in intensification of resource use, adding to the problem. Instead, the industry needs to increase sustainability, he said. Increased efficiency in production can reduce GHG emissions while addressing the increased demand for agricultural products.

The USDA is “looking at climate change and the risks and vulnerabilities farmers are facing.” Increasing agricultural productivity “can happen a lot of different ways,” Hohenstein said. “The USDA has tremendous capacity to work with farmers across the country,” and “help position farmers to deal with climate variability and climate change.”  PD

Hohenstein spoke at the Dairy Environmental Systems and Climate Adaptation Conference held at Cornell University in July.

Tamara Scully, a freelance writer based in northwestern New Jersey, specializes in agricultural and food system topics.

ILLUSTRATIONS: By Kristen Phillips.