<p><span><span><span><span><span><span><span><span><strong><span><span><span>Greenhouse gas (GHG):</span></span></span></strong></span></span><span><span><span><span><span><span> Any of various gaseous compounds (carbon dioxide for example) that trap heat or longwave radiation in the atmosphere and contribute to the greenhouse effect.</span></span></span></span></span></span></span></span></span></span></span></span></p>
