Spending is a lot easier than taxing.<p>A country could just offer to buy a increasing amount of zero emission electricity and sell it on the free market until electricity was no longer generated from sources that yielded carbon.<p>The same approach could work for battery cells that could be used in cars until non-electric vehicles were no longer competitive.<p>This could be funded by that country&#x27;s current (probably) progressive tax system.<p>This doesn&#x27;t cover air, sea, heating and agriculture emissions.  But a carbon tax may not be an adequate incentive to develop electric aircraft or cargo vessels in any case.