One of the world's main producers of methane gas is not a factory or a machine, but rather the common dairy cow. When a cow ingests ordinary grass, microscopic flora in its stomachs convert some of the plant material into methane gas. This methane gas is expelled in two directions, but primarily through burping. The gas eventually reaches the upper layers of the atmosphere as one of several greenhouse gases, and the ultimate result is global warming as these gases become more concentrated.
To address this methane gas production issue, scientists in Australia and the UK have been working to develop a "burpless grass," a hybrid species of grass which is much easier for cattle to digest, thus reducing the amount of methane gas each head of cattle produces during an average day. Considering that some experts believe cattle are responsible for up to 14.7% of all greenhouse gas production, any reduction in methane gas production can only help the cause of environmental responsibility.
Burpless grass has another benefit besides higher digestibility. The strains of experimental burpless grass developed by Australian scientists have also proven to be more heat resistant than most standard grasses. This means that a field of burpless grass can be grown and maintained in harsher climates, allowing beef producers to continue raising cattle even if global warming affects their current fields in the future.
Burpless grass works by manipulation of the natural enzymes found in regular grass strains. One particular enzyme, O-methyltransferase, is effectively neutralized in burpless grass hybrids, which makes the grass more digestible and therefore less liable to produce excess methane gas. Methane gas production is not completely eliminated, however.
One criticism of burpless grass is that the total amount of methane produce could be even higher, since more of the digested grass will pass through the cow's digestive track and end up in the methane-producing manure. While this is a legitimate consideration, the scientists who developed the burpless grass argue that the increased milk production would offset any increases in total methane gas.
This would be the equivalent of putting a higher octane gasoline in a car's engine. There may be an overall increase in exhaust gas emissions, but the car benefits from increased mileage per gallon. Cows who ingest burpless grass may emit more total methane gas, but they also produce more milk per enriched portion of grass.