CO2, Climate and Farming
May 2005 Weather Feature
Frank Watson, Meteorologist

A report released last month by National Oceanic and Atmospheric Administration (NOAA) reported after spiking between 2001 and 2003 carbon dioxide (CO2) has return to lower increase levels. CO2 is an important gas that traps heat and contributes to the greenhouse effect and warmer global temperatures.

Making decisions on water resource management and agriculture planning we need to better understand the effects of warmer global temperatures. Where we live, what food we can grow or how we grow the food, and where organisms we consider pests can thrive all depend on a better understand of future global temperatures.

Since CO2 is one of the most important greenhouses gases lets take a closer look. CO2 is a gas that is released into the atmosphere through the burning of wood, coal, oil, and gas. Almost 7 billion tons of carbon, in the form of CO2, is released into the atmosphere through the combustion of fossil fuels and other materials. CO2 data collecting began in 1958 at the top of Mauna Loa volcano and has recorded increases in CO2 levels every year.

Fortunately for us oceans and plants absorb CO2. Plants are able to absorb 20 times the amount of CO2 that is generated every year. While this seems like great news the problem comes in that as plants decompose CO2 is returned to the atmosphere.

An item that has generated little interest is the practice of no-till farming but may gain interest in the future. When farm fields are plowed or tilled, as the top layer of soil is turned over carbon is released into the atmosphere. Carbon plays a valuable role in farming in that the decaying organic matter provides nutrient to plants. Fertilizers are used to replace lost nutrients from plowing.

Tilling is beneficial in that it aids in the removal of weeds, making it easier to use fertilizers and pesticides and to plant crops. Soil is enriched as tilling hastens the decomposition of crop residue, weeds and other organic matter.

On a less positive note tilling exposes the soil to wind blown erosion and makes it easier for fertilizers to wash away. The United States leads the world in no-till farming at 37% of the nations cropland while the rest of the world is at 5%. Reports say that if every farmer who grows crops in the United States would use the no-till and adopt other management practices 300 million tons of carbon would be retain in the soil each year. Granted 300 million tons is a drop in the bucket compared to the 7 billion tons released by fossil fuels and is at best a small piece of the solution puzzle.

While the increase in CO2 has slowed since its peak a few years back CO2 levels are still on the increase. As more data is collected and studied we'll be able to make better decisions for understanding future climate conditions and farming practices.

Frank Watson is a White Bear Lake, Minnesota meteorologist and can be found on the web at WeathermanWatson.com