Study Tries To Drive A Nail In The Coffin Of Diesel Vehicles - Claims Scientists Had No Idea How Bad They Really Are

Everytime one of these studies is published a peer reviewer scientist should ask how it was done, what assumptions were made, the source of the data, who paid for it, these days the politics behind it, etc etc. The Dilbert comics on Sunday 5/14/17 get at the issues. See it by a "cut and paste" of this net address.
http://dilbert.com/strip/2017-05-14

There is a lot of that going around on on all sides.

Agree - these studies are like the old adage - if you put one hand in a bucket of ice - and the other over a raging fire - somewhere in between you will be comfortable.

Again - while all cars emit more than they do during the EPA test cycle - because of the closed loop under controlled conditions are not a duplicate of real conditions. However - one must have a controlled environment for these tests - so that all cars will be tested under the same conditions. And - the fact is - when emissions are reduced in a test - they are also reduced in the real life - just the numbers are different.

Remember - the largest emitter of Hydrocarbon emissions into the air - are from Evergreen and PINE trees. And we could not enforce a law against Santa Trees!

I encourage people to differentiate between "scientists" who work for someone, such as an automotive manufacturer or Philip Morris, and ones who are independent and who are not aligned with a specific outcome.

For example, the linked article asserts "[diesel engines] produced 50 percent more nitrogen oxide than scientists previously thought..." Well, no, that's not the case. No scientist worth his weight in sand would believe that an in-lab-only test would accurately depict a vehicle's emissions when operating in the real world, and that's exactly the comparison we're making. Legitimate scientists did NOT believe the lab numbers were meaningful; that's an assertion made by the auto industry, and supported by legislator who made laws according to that understanding.

In fact, anybody who spends a little time investigating scientists' position on vehicle emissions will quickly learn that scientists have been telling U.S. authorities for well over a decade that actual emissions are much, much higher than those reported by the manufacturers' lab numbers, yet nothing was done about it.

The linked article also does a shoddy job in disclosing vehicle emissions as a problem, as it focuses only on diesels. In late 2015, shortly after Dieselgate exploded onto the scene, the UK government conducted their own real-world emissions tests, and they discovered virtually all vehicles tested (diesel and gasoline, multi-brand, multi-model) exceeded lab-legal emissions by far when operating in the real world, and VW's diesels weren't the worst overall polluters. And yet, to this day, the media continues to focus on "dirty diesel," and the masses gobble it up, hook line and sinker.

It isn't only scientists who work for a given industry who can be biased. Universities and various other institutions also are biased due to the where their funding comes from or things like a universities positions on things like fossil fuels etc. "You show me how you are measured or paid and I'll show you what you do"; David Packard many moons ago If I can get a grant to do certain research and the outcome will get me more grants, guess what.

Modeling leaves a LOT of room to shade things in different ways. So far a lot of the models on climate pushed ten years ago haven't proven to be totally accurate. One should expect that.

The sooner diesel is gone the better.

I do not support people who vilify or idolize a technology (e.g., diesel must die / gasoline-electric hybrids must rule).

I'm all for cleaner emissions, regardless of the technology[1] used. Burn cow paddies for all I care. If you meet emission laws, great!

_____
[1] Assumptions include:
- Legitimately cleaner, not just gaming the system
- Not making vehicles less safe than they are now
- NOT clean emissions at the cost of ethics
...and so on.