No Sybil, it is not the corporations.
The government is well aware that the majority of countries that
produce the most CO2 will continue to do so.
However politics demands that they do something.
So 3% will have the smallest effect on the country consistent with
keeping the politics happy.

The greens have seen through this of course but they are prepared to
sacrifice the country on the alter of holy greendom despite that
Australia, Europe and the US will have no effect on CO2 levels.

The whole global warming politics is starting to be overtaken by the
reality of peak oil and depletion. It is producing economic tensions
even before shortages develop.
Oil and later coal depletion will reduce CO2 quicker than politics will.
See article by Kraus on the Oil Drum.