By Frank A. Hilario

Climate change is the world’s Number 1 science topic today, and it relates to crops in Agriculture such as rice, corn, and wheat. Actually, it relates more to crops in Horticulture, because there are more of them grown: banana, cacao, coffee, coconut, flowers, fruits, fruit trees, medicinals, ornamentals, and vegetables.

The trigger for climate change is global warming. Now, such warming results from greenhouse gas emissions that rise to the Earth’s atmosphere and cause the global greenhouse effect. Above, the helpful twin-image illustrates what is the greenhouse effect, from “Climate Basics for Kids,” Center for Climate & Energy Solutions or C2ES, c2es.org. The website says:

Scientific evidence paints a clear picture: Climate change is happening. It is caused in large part by human activity, and it will have many serious and potentially damaging effects in the decades ahead. Greenhouse gas emissions from cars, power plants and other man-made sources – rather than natural variations in climate – are the primary cause(s).

Other man-made sources include the manufacture and use of diesel fuel, gasoline, and fertilizers.

And why did I choose as source of illustration this one dedicated to children in school? Because it does not assume that we know anything about climate change, and really basically we do not!

C2ES says:

We can help you understand how and why our climate is changing, how climate change affects us, and what people can do to slow climate change and prepare for it.

I say:

The left image at left shows the rays of the sun passing through the red layer of greenhouse gases: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Part of the solar heat not absorbed by Earth is radiated back to the atmosphere; since the layer of greenhouse gases is thinner, it allows much of that heat to dissipate into outer space harmlessly.

The right image at left shows the same process going on, but there is now a very-much thicker layer of greenhouse gases, and so there is very much less solar heat escaping into outer space – causing global warming. That is why climate has changed – in the Philippines, when the rainy season comes, there is so much more rainwater that it causes heavy floods; when the dry season comes, there are many more and dryer days, that it causes droughts that are bad for crops and people.

And how does inorganic, or non-organic, or conventional agriculture contribute to climate change? From agriculture, CH4 is emitted by livestock and N2O comes from nitrogenous fertilizers used by farmers (US EPA, epa.gov).

“The large increase in the use of nitrogen fertilizer for the production of high nitrogen-consuming crops like corn has increased the emissions of nitrous oxide,” say Eugene Takle & Don Hofstrand (“Global Warming – Agriculture’s Impact On Greenhouse Gas Emissions,” Iowa State University, extension.iastate.edu). CH4 comes from the belching of livestock in the farm. Manures left in lagoons, ponds, tanks or pits decompose and emit CH4. The use of gasoline and diesel in agricultural production generates much CO2 gas.

In the Philippines, the high nitrogen-consuming crop is rice. As a board member of the Nagkaisa Cooperative with mostly farmer members in Asingan in Pangasinan, and as once an extension consultant of the Department of Agrarian Reform, I know Filipino farmers apply an average of 10 bags/ha/cropping. What happens? From the University of Melbourne in Australia, Ee Ling Ng, Dell Chen & Robert Edis say (04 December 2016, “Nitrogen Pollution: The Forgotten Element Of Climate Change,” The Conversation, theconversation.com), and I quote:

Nitrogen emissions such as ammonia, nitrogen oxide and nitrous oxides contribute to particulate matter and acid rain. These cause respiratory problems and cancers for people and damage to forests and buildings.

I didn’t know that nitrogen fertilizers contribute to damage of forests and buildings! We always learn something if our mind is open. I continue quoting:

Nitrogenous gases also play an important role in global climate change. Nitrous oxide is a particularly potent greenhouse gas as it is over 300 times more effective at trapping heat in the atmosphere than carbon dioxide.

I know about nitrous oxide and climate change; I have been writing about their relationship for years! See for instance my essay “The Boys Who Cried Wolf. Stop The Fire. Stay The Ice. Start The Peace,” that I blogged 11 years ago (07 February 2007, Frank A Hilario, blogspot.com). N2O is 300 times more dangerous than CO2 in terms of global warming, and that is why nitrogen fertilizers like urea and ammonium sulphate are helping farmers increase their yields but are dangerous to all of us as they increase much the heat of the Earth.

I continue to quote:

Nitrogen from fertilizer, effluent from livestock and human sewage boost the growth of algae and cause water pollution. The estimated AU$8.2 billion damage bill to the Great Barrier Reef is a reminder that our choices on land have big impacts on land, water and the air downstream.

And yes, also 11 years ago, Greenpeace reported that drinking waters in the Philippines and Thailand were already contaminated with nitrates, arising from heavy chemical fertilization in farm areas (22 November 2007, “Drinking Water In Philippines, Thailand Contaminated With Nitrates, Greenpeace Says,” Greenpeace Philippines, greenpeace.org). With high levels of nitrates, such water “can cause serious problems, especially in children,” says Greenpeace. Such water has also been associated with cancers of the digestive tract, non-Hodgkin’s lymphoma, bladder and ovarian cancers.

To summarize, here is something that should wake up government officials especially in PH Department of Agriculture:

Nitrogenous fertilizers pollute our waters but more so cause climate change!

So, what is climate change? To be practical about it, as well as to be location-specific:

In the Philippines, climate change is the coming of dangerously drier and warmer months during the dry season and dangerously wetter and colder months during the wet season. Both are caused by global warming, which in turn is caused much by nitrogenous fertilizers used for growing crops all over the world.

This appeared in Agriculture Monthly’s December 2018 issue.