The world has more nitrate, NO3, than in the past. It's a life giving plant nutrient that is often in short supply since it is always in high demand. Much of that increase has been attributed to emissions from fossil fuel combustion, which produces nitric oxide (NO) and nitrogen dioxide (NO2) collectively referred to as NOx, which are precursors to NO3.

Another source of NOx is lightning.

more than 1.2 billion lightning flashes occur around the world every year. (Rwanda has the most flashes per square kilometer, while flashes are rare in polar regions.) Laboratory and field experiments have revealed that the core of some lightning bolts reaches 30,000 Kelvin (53,540 ºF), a temperature hot enough to instantly melt sand and break oxygen and nitrogen molecules into individual atoms. . .

Fossil fuel combustion, microbes in the soil, lightning, and forest fires all produce NOx. Scientists think lightning's contribution to Earth's NOx budget—probably about 10 percent—is relatively small compared to fossil fuel emissions. Yet they haven't been sure whether global estimates of NOx produced by lightning are accurate. . .

According to a new paper by Ott and Pickering in the Journal of Geophysical Research, each flash of lightning on average in the several mid-latitude and subtropical thunderstorms studied turned 7 kilograms (15.4 pounds) of nitrogen into chemically reactive NOx. "In other words, you could drive a new car across the United States more than 50 times and still produce less than half as much NOx as an average lightning flash," Ott estimated. . .

A decade ago, many researchers believed cloud-to-ground lightning produced far more NOx per flash than intracloud lightning, which occurs within a cloud and far higher in the atmosphere.

The new evidence suggests that the two types of lightning produce approximately the same amount of NOx per flash on average. But since most lightning is intracloud, this suggests a great deal more NOx is produced and remains higher in the atmosphere. Compounding this effect, the research also shows that strong updrafts within thunderstorms help transfer lower level NOx to higher altitudes in the atmosphere. . .

There's a possibility that lightning could produce a feedback cycle that accelerates global warming. "If a warming globe creates more thunderstorms," Pickering noted, "that could lead to more NOx production, which leads to more ozone, more radiative forcing, and more warming," Pickering emphasizes that this is a theory, and while some global modeling studies suggest this is indeed the case, it has not yet been borne out by field observations.

These folks were worried about ozone and climate change - the money subjects - and made no mention of the implications of increased nitrate production. That feedback model would be complicated by increased plant growth and greater carbon uptake by the biosphere. Out here in the toolies you may find two growers talking across the fence and watching the sky as storms approach. They not only pray for rain, they pray for lightning since that means that the rain will contain more nitrate and fertilize their pastures for them.