I'd like to comment on the contention (Weekend Sun, December 18) that increased emanations of methane from melting tundra would increase global warming.
Methane, or marsh gas, as it was one time called, is given off from decomposing organic matter when it has no oxygen available.

It verves out of ponds, marshes, bogs and comes from humus in soils, and city rubbish dumps.

It is highly inflammable and the gas bubbling out of marshes often burned with its characteristic value flame.
This flickering blue light,when seen at night, was called
‘Will o' the wisp'.

Methane has been pouring into the air for thousands of years, yet it does assimilate there although it is not soluble in water, and is not taken up by plants.

Where has it gone? The answer is simple. This very inflammable gas burns, being easily ignited by the thousands of lightning strikes that occur daily. Methane does not accumulate in the atmosphere.

J Mills, Mount Maunganui.