Dummy "it and Usage of "as To

I do not think OP's example is an appropriate use of as to (which in such contexts can normally be directly replaced by regarding, concerning the matter of, in respect of, etc.).There's probably no clear-cut "grammatical rule" here, but I do not like #2 or #3 above, and I would like them even less if as to were replaced by any of my suggested alternatives.1It's hardly worth trying to identify an actual "thing" referenced by it - things might seem clearer if we recast #1 as "How this accident happened is unclear", but most native speakers probably just see the usage as akin to "It's raining", "There's a storm coming". As John Lawler points out in this ELU answer...Which to my mind means it (and there) in such constructions do not really have any "meaning" at all - they are simply forced on us by the rules of grammar/syntax. It has various names, including weather "it", existential "it", existential "it", anticipatory "it", but I would say the first of those is misleading because it applies in more contexts than just the weather; the last because often the "real" subject is never specified. 1 But see my comment below. I do not object to as to how in general, but that seems to change in constructions with only a "dummy" subject. Recasting #2 as above......I can "fix" the (to me) unacceptable #2a by re-introducing a dummy pronoun. But note that whereas the original #1 can appear as an initial utterance, #2b is only valid in an already ongoing "conversation". That's because as to means turning [now] to, and you can not do that unless the dialogue has already started (so it has a "focus" from which you can "turn away" to discuss how the accident happened).TL;DR: Syntactically, a wh-word (what, when, where, who, which, why and how) can serve as a "subject", but as to [how, why, etc.] can not

1. What are the current researches on environmental chemistry?

Go to the website of the Journal of Environmental Chemistry and Ecotoxicology. On the website, there is a "search" tool. When I search for "October 2011 environmental chemistry" I get the table of contents for this journal's Oct 2011 issue. It includes such articles as: "Kinetic and equilibrium studies of the adsorption of lead (II) ions from aqueous solution onto two Cameroon clays: kaolinite and smectite" "Ruditapes decussatus embryo-larval toxicity bioassay for assessment of Tunisian coastal water contamination" "Physicochemical dynamics of the impact of paper mill effluents on Owerrinta River, eastern Nigeria" I do not know if this particular journal is for some reason focused on Africa (all three of the above-mentioned countries are there)...you could find out by going to the site and searching for "September 2011 environmental chemistry," etc., back in time. Of course, not all problems in environmental chemistry are water-pollution problems. Try Journal of the Atmospheric Sciences and peruse their article titles to see some that are chemically-oriented (as opposed to dynamics, radiation, weather, etc.).

2. what is the normal weather in Ireland?

Cold in winter Warm in summer If you live by the sea then it will be windy Ireland is so lovely!!

3. Can you tan in this weather????

Just a waste of time and causes cancer later in life

4. What to wear in this weather?

honestly, any of those would really work in this weather, like i have people at school wearing flip flops and people wearing uggs. my personal favorite is flats so maybe get a pair that does not make your feet hurt, and also wearing tennis shoes always works in whatever weather

5. Atheists : What do you think about trans-humanism?

I think it's extremely interesting. Humans have always shown that once they have the ability to alter their bodies in some way, someone somewhere will push it as far as it can go and beyond. It happened with tattoos. It happened with hair dyes. It happened with piercings. Now we've got even more extreme methods of body modification, and we've already got untold numbers of people walking around with bifurcated tongues, coral horns, corset-pierced backs, fang-like incisors... not to mention the truly insane modifications like genital bifurcation... Trans-humanism at least has the potential to me far more than cosmetic. Enhancing the ability to cope with extremes of weather, opening up new pathways of communication, even simple things like personalising locking mechanisms to make home and property security more effective. Genetic transhumanism is interesting, but for some reason I find the technological aspect more fascinating. One great, relatively mainstream writer who deals with it is Warren Ellis. If you get the chance, have a look at his comic series "Doktor Sleepless". He has some interesting ideas about how social media may evolve alongside transhumanism. His short stories have even stranger concepts, such as a man who falls in love with his self-modifying smart car for some hilariously vulgar reasons...