Legislating exhaust emissions a complex task

Almost any measure which will significantly reduce harmful vehicle exhaust emissions is a good thing.  So the simple answer to current talk of legislation to toughen up Kenya’s emission standards is:  Go for it!

However, exhaust emissions are not simple. Not in their contents. Not in their causes. And not in the best remedies to reduce them.

And, therefore, least simple of all in the design and enforcement of legislation to cut the crud, which must consider all sorts of factors other than just the “freshness” of the air we breathe.

The single most important thing is for policy makers, law makers, law enforcers, media, and by extension the public, to recognise how complex the subject is. There is no silver bullet even in theory; less still in practice. And there are dozens of interactive factors and side-effects that can turn the best intentions into a socio-economic (and even environmental) mess.

The best that any legislation, on any of these factors, can achieve is the “potential” or “possibility” of reduced exhaust pollution. Even that moderate ambition begs four rudimentary questions, none of which the public yet has an answer to.

 1 What form of pollution is most serious?2   How bad is it and why?3  What remedies will be most effective?4  Of these, which should have priority (vide cost, practicality etc) in our particular and especially complex context?

On the first question,  “motor vehicle exhaust fumes” might, or might not, be a significant contributor compared with many, many other sources of pollution, even if we consider only airborn toxins.

The rear ends of our motor vehicles are often far from pretty, but by global standards we have very few of them – either in total numbers (about 0.1 pc of the world population) or in air-space density.In the absence of robust data on Question 1, everything that follows must be prefaced with if, if, and if.

But presumably that data has been gathered (though not shared) as the very basis of the proposed legislation. So a paraphrase of Question 2 might be:  tell us what is in our air, how much of the bad stuff there is, and where it comes from.

And if, a significant proportion is coming from vehicle exhausts, why are our vehicle exhausts so toxic? For surely the answers to that are fundamental to designing the remedy.  Is it because too many of our vehicles are too old (in design or wear), or because they are poorly maintained, or badly driven, or because they spend most of their time in stop-start traffic instead of cruising at a moderate and steady speed (I would bet my shirt that the last option is the most causative of the most toxic outputs).

So, do we need newer vehicles, public education on service practices, better driving tuition, or roads, signs and user practices that let traffic flow? All of the above, of course. But which is the priority? Which would have greatest and surest effect at lowest cost? A glimpse in that direction…next week.