Yep - I read earlier this week that when they did a life-cycle analysis for a Toyota Prius it's overall environmental footprint is twice the size of a similar "normal" car. A lot of this was down to the production and disposal of the battery-pack.

In terms of CO2 bikes with decent performance are pretty awful for their size. They aren't much better (and are often worse) than a small car and a high proportion of performance bike miles are done 'going for a blast' rather than going somewhere in particular.

In terms of regulated pollutants they're behind as well. Cars and trucks are at Euro 4 emissions level and Euro 5 is on the horizon.

In their benefit they cut congestion, so urban pollution is reduced.

There are rumblings about restricting bike size / power / number of cylinders but, because there's a lot less of them, the overall contribution to air quality improvement will be less, so governments are tackling higher priorities. My guess is that in about 5 years time (when Euro 6 is close for cars and trucks) bike emissions will be significant enough for more drastic measures to be introduced.

Cheers Keith

But then, bikes usually have ridiculously short life spans... Not to mention that putting a cat on a bike so it can get through emissions testing, knowing that the user will remove it immediately, is insane... All it does is move pollution to manufacture side instead of use side, and cats are very harmful to produce (not to mention the amount of useful resources going in skips)

I think the real reason motorbikes/scooters are exempt from the congestion charge is that the congestion charge cameras read the front number plate of cars.
Bikes don't have front number plates and were removed some years ago for safety reasons; I think its actually illegal to have a front number plate.

If the congestion cameras could read our plates we would have to pay the charge. Bikes causing less congestion than cars is not why we don't pay the congestion charge.

i'm in ur can, eating ur emissions

hehehe

I would think the reason bikes are exempt from the congestion charge is because they don't cause it.

Yes. This is true of a lot of environmental things. Solar panels generally do more harm than good (because of the large environmental impact of manufacturing and disposing them). Most recycling of plastics uses more energy than it saves, etc. I'm not saying all recycling is pointless- recycling glass bottles is good (ideally without smashing them first- more bottle reuse like milk bottles). Ripping up old newspapers and spreading them on your lawn is a good for the soil, etc.

I do get the impression that a lot of our green friends are more bothered about going through the motions of trying to make a difference, rather than the net end result for the planet. :roll:

I am afraid I am red and very noisily so at that! EC/PC my a*se! :D