Uh, hold on.....
OK for the sake of the rest of this thread let me lay down what I know about emmission controls so we are somewhat on the same page.
Traditionally emmissions fall into 2 major categories: Hydrocarbons and oxides of nitrogen.
But since the mid '80s weve seen plenty, and I do mean plenty, of evidence that CO2 could do us a lot of hurt too, in the long run.
Hydrocarbons
Bikes dont have controls that assure complete combustion of fuel. Optimal combustion mixture for maximum power is slightly rich, meaning that the excess fuel is pumped into the atmosphere as partially combusted molecular hydrocarbon fragments. These things react with gasses in the atmosphere and the sun's rays to form smog
Hydrocarbons are controlled by careful mixture manipulation and by catalytic converters, which complete combustion on the surface of a honeycomb coated with special materials in the exhast pipe.
Oxides of Nitrogen
involving of nitrogen in the cumbustion process is unavoidable, it composes 70% of the atmosphere. N2 is the most comon form of atmospheric nitrogen and it's really stable, meaning it's really hard to oxidize. High combustion pressures and temperatures are enough to split N2 though, creating oxides of nitrogen NO2 and NO collectively known as NOx. NO2 is the real baddie. it reacts with the atmosphere to produce ozone (O3) which is a very reactive chemical that loves to oxidise just about anything, including say, lung tissue.
Lets not confuse this stuff with the O3 that is famously disappearing in the high atmosphere and is useful for shielding us all from UV rays which causes cancer and would sterilize the planet of all multicellular life if all the high atmosphere O3 goes away. No, the stuff we creater down here never makes it up there. It's highly reactive remember? the High altitude O3 has very little chance to react because the atmosphere is so thin.
Oxides also react to form nitric acid, which is a major contributor of acid rain, as well as toxic organic nitrates.
NOx can be limited by lowering combustion temperature, usually by admitting some spent exhaust gasses into the intake(EGR), not a great formula for maintaining max power. But EGR is usually only implemented during cruise modes so it is not noticed very much. It pisses me off when "Hot Rodders" disable their EGR thinking they are gaining a bunch of power. They don't but they do increase the chances that my kid will get asthma.
Now, a bike with no emmission controls, tuned for maximum power definately has the potential to release more of these pollutants than a car or truch with state of the art, or even last generation emmission controls.
Now, what Cheapskate could conclude using his line logic is that motorcycles are not going to release more CO2 which is directly related to how much fuel and air is used.
CO2 reduction is a *****, but the result is better fuel economy.