tax carbon emissions
... that Canada has enacted a cap and trade program to tax carbon emissions?
... that Canada has enacted a <a href="./Emissions_trading" id="mwBy8" rel="mw:WikiLink" title="Emissions trading">cap and trade</a> program to <b id="mwBzA"><a class="mw-redirect" href="./Carbon_price_(Canada)" id="mwBzE" rel="mw:WikiLink" title="Carbon price (Canada)">tax carbon emissions</a></b>?