Where are all the gay scientists? On one level the answer to this question is obvious: lesbian, gay, bisexual and transgender (LGBT) scientists are in their laboratories all over the world doing great research. But in some less obvious ways they are almost entirely absent.

With the anniversary of Alan Turing's death last year the question was being asked afresh, but LGBT History Month 2014 is here and the situation has not improved. Over the past year, hardly any scientists featured on lists of influential LGBT people, such as the Independent on Sunday's Pink List of 101 LGBT people who make a difference; and the Guardian's World Pride Power List of the 100 most influential LGBT people of 2013.

One explanation could be that the scientific environment has been a hostile one for LGBT people. The world was a very different place when I was starting my scientific career in the 1980s. Section 28 was on the statute books and LGBT discrimination in employment was commonplace and perfectly legal. Far fewer people were out at work, regardless of their profession, for fear that it could damage their career.

In science you are constantly judged on the quality of your last research paper, in what is often an aggressively competitive environment. You might have an arm growing out of your forehead, but when you walk into a room of scientists, the first thing they ask is "what research do you do?". This is not scientists being unfriendly. It's simply that your sexuality is not the most interesting piece of information about you, which I have always found liberating.

I should say that I don't think of myself as an out gay scientist; what I am is bloody obvious. For me, it has never been a question of whether to tell people that I am gay, but rather of whether I want to expend energy on pretending not to be. Yet as I look back over my 30-odd years as a scientist I really can't see any point at which being obviously gay has in any way limited my choices or chances.

Of course, I may have been particularly lucky, or sufficiently stroppy, that being gay has been such a small issue in my scientific career, and colleagues have always been welcoming to me and my partner. And I know I'm not alone. As I go about my business, I meet many other happy, out LGBT scientists.

So if the scientific world is at least no worse a place to be LGBT, then what other reasons are there for the apparent absence of LGBT scientists?

Sadly my experience of being "out" as a scientist in the LGBT community is quite different to what I describe above.

When I tell people I'm a scientist, they typically respond with the dismissive "I hated science at school" (in other words, please don't bore me by saying any more) or insulting "you don't look like a scientist" (I'm supposed to think of this as a compliment?).

I am also a chemist, so frequently find myself apparently personally responsible for the wholesale and wanton destruction of the environment. Or being told that it's only my closed mind and the evil pharmaceuticals industry that stops homeopathy curing cancer. This last one is the most annoying since I have been cured by a course of chemo-radiotherapy.

Instead I often find it easier to say "I'm a teacher".

If my experience is typical of others', then it is not difficult to see why scientists do not appear in these lists. Most scientists, medics and engineers know that unless they have a stethoscope around their neck they aren't valued and either don't get the opportunity, or simply don't bother, to talk about the positive contributions they make every day to society.

In 2014, the Guardian and Independent on Sunday could do a lot worse than appoint someone to their judging panels who can recognise the value of what scientists and engineers do and some of the fantastic LGBT scientists out there will get the credit that they deserve from their own community.

• Tom Welton is professor of sustainable chemistry at Imperial College London