carbon accounting
... that laughing gas is serious stuff in carbon accounting?
...  that <a href="./Nitrous_oxide" id="mwNA" rel="mw:WikiLink" title="Nitrous oxide">laughing gas</a> is serious stuff in  <b id="mwNQ"><a href="./Carbon_accounting" id="mwNg" rel="mw:WikiLink" title="Carbon accounting">carbon accounting</a></b>?