| Topic: | Re:Putney High Street - disgraceful example for air quality inaction | |
| Posted by: | Richard Hodges | |
| Date/Time: | 29/01/13 14:41:00 |
| Why do you insist on posting this rubbish, when it has been repeatedly debunked on here and elsewhere. - We have known for a decade that buses are the primary automotive source of NOx in London. - NOx (and other) emissions from cars are massively down from their peak, by three-quarters and more. That's not per vehicle, that's total values, including the allowance for the increases in traffic over the same period. - Data from the introduction of congestion zone indicated even back then, cars were actually reducing NOx levels, by completing a second, more efficient combustion cycle of the exhausts from other vehicles. - Since then the LEZ was introduced, affecting heavy and light commercial vehicles, but exempting buses. - It's nearly three years since some of us explained this, backed actual research and experience with the design and installation of engines in motor vehicles. - Eighteen months ago data from the kerbside monitoring unit directly and absolutely confirmed all the above. Let's look at those numbers again. - Buses represent 10% of PHS traffic but are the cause of 66% of the NOx. - Heavy commercial vehicles (lorries, trucks, coaches & fie engines) account for another 10% of traffic, but produce much less than half the NOx. - Light commercials (vans, ambulances, taxis) account for another 25% of traffic. Most if not all are now at Euro V or better and produce a small fraction of the total NOx. - Cars and motorbikes represent the remaining 55% of traffic and produce a small fraction of the total. This is real-world data, not chamber tests. Your claim about those naughty auto makers fixing NOx results shows a complete lack of knowledge of both the production mechanism of nitrogen compounds in the ic engine, and the test methods used. And now this month, TfL have finally admitted that the buses that have been contracted for use on PHS have been producing up to EIGHT times what they could have been producing if TfL had acted responsibly and upgraded their emissions equipment. TfL made sure they were excluded from the LEZ controls, whilst almost all other modes have made great strides forward. They have persisted with running vehicles to long out-of-date emissions standards. The data has repeatedly shown that buses are far and away the worst culprits on PHS, and that's just considering the primary impact (ie what comes out the exhaust). The evidence further suggests that the planned replacement and upgrade programme (if fully and properly implemented) could reduce automotive NOx emissions on PHS by one third or more. I won't claim the meter readings will reduce accordingly, because there are several other significant, non-automotive sources affecting Putney, which people are unwilling to consider. The time to address those will come. But the bottom line is that in terms of automotive sources, there is only one game in town. Have you not considered that during the ten years in which "in many places NO2 levels have stayed pretty static for ten years", all vehicle types except one have had to meet dramatically enhanced standards? Some of us twigged that years ago. It's about time you caught up. This isn't the first time I've had to pull you up for talking rubbish, and I'll continue to do it. You're not helping. |