Absolutely; the combinatorics here are huge. The UN has 6 official languages [0], the EU has 24 [1]. There are ~25 languages in the world with more than 50 million native speakers [2]. Does anyone think that science would be more efficient (or effective) if it had to be continually translated between a similar number of languages?
[0] http://www.un.org/en/aboutun/languages.shtml
[1] http://ec.europa.eu/languages/policy/linguistic-diversity/of...
[2] http://en.wikipedia.org/wiki/List_of_languages_by_total_numb...
This. It's also one the feature I personally most love in English. In principle, you can invent new words in every language; in practice, not every language culture allows you to do that freely. I like thinking in English because of its flexibility. If I need so, I can e.g. verb a noun on the fly and everyone understands what's going on. Bending the language to better express your thoughts is easier in English than in, say, my native Polish.
So if German has some quality similar to English, that could still be part of what makes a language gain dominance in a field.
I gather that Egyptologists find it extremely convenient (bordering on necessary) to be able to read modern French and German, which are the languages of important Egyptology journals and books. After that Arabic wouldn't hurt, and I'd guess Russian would be nice (less certain on that one). That's in addition to the languages of their primary and contemporary secondary sources, mind you, which are very important but not used to write up new research :-)
Likewise those studying the history or politics of many other regions are aided by knowing French or German or both, plus local and historical languages obviously. In at least some sub-fields of philosophy I'd expect French, and maybe other languages, to be practically a requirement for keeping up with new work and developments.
Many native English-speaking economists and political scientists likely did benefit or could have benefited from being able to read French for Piketty's book, which didn't reach the English language until months later.
I don't know what effects, positive or negative, this has on the people who work in those fields.
This is false. If science were still conducted equally in German, Russian, French and English, up and coming scientists in China, Japan, etc. would have to learn four languages to keep up with their field instead of just English. Conversely, assuming such newcomers rise to the forefront of their field, they might choose to publish in their own language, foisting a new language on everyone else.
One aspect of English that the author overlooks completely is how welcoming it is of new words. French, for example, has the "Académie française", which is an institution charged with maintaining the purity of the French language. This means resisting change and controlling the vocabulary in use. There are dictionaries for English, but those who maintain them simply try to keep up with common usage, not control what becomes common usage. If a researcher finds that they need a term that does not exist in English, it's trivial to invent a new word or, more commonly, borrow one from another language.
The author of this article argues that English speaking countries exert undue influence on science because of scientific monolingualism. However, English has been extensively modified to suit those who wield it in print, and an increasing proportion of them are not native speakers of English. English is rapidly becoming the world's language. One could just as easily write an article bemoaning the plight of Anglophones, whose native tongue is no longer something they control!