For example, the number one 'problem' with a space elevator is, as the author correctly states, producing a material with a sufficient strength to density ratio with which to construct the tether. Though his numbers on this are not entirely correct, it is true that material science is far from producing a substance rendering S.E. construction feasible. However, the argument that the project is a dud because construction cannot begin today is absurd. Over the past one hundred years, the field of material science has taken many leaps, each paving the way to new technologies. The space elevator is not the first technology that needed to patiently await a strong enough and light enough material, and it will not be the last.
Furthermore, I take issue, personally, with his 'problem #3', about climber excitation, which happens to be one area I have researched extensively. My research found the extent to which a climber excites the tether (it is proportional to lifted mass, distance climbed, and climber speed), and proposed some reasonable methods to mitigate such effects. With respect to all of the big challenges associated with the space elevator, this one has been shown to be minor.
In the paragraph about tether excitation via climbers, I (along with a McGill University engineering professor) am quoted. These comments were made back in 2008, and the quote, I can only assume, was lifted from another article that was published at that time. I still stand by those comments, and, as I did then, conclude that this particular challenge is a manageable one. Had the author sought a comment from me in 2013, I would have explained this to him. I also would have told him that I have not worked at MDA Space since 2009; according his article, I presently work there.
I could go on about how the author warns of the space debris challenge without even mentioning the major study that was recently conducted on it by ISEC (it concluded that the space debris challenge is a manageable one), but there is a far bigger oversight. Had the author spoken recently to an expert in the field, he would have known about the up to date feasibility study about the space elevator that has been conducted by a number of researchers over the past year or so. It is known as the Cosmic Study, and there is no mention of it in his posting.
I am one of the contributors to the Cosmic Study, which is currently being finalized. At this point, I believe that the space elevator project will be realized during my lifetime. If I had to pick a year, I'd say 2050, because it sounds good, but in truth, one cannot forecast so far into the future with a high degree of precision.
There are still a few areas of preliminary S.E. research that need to be conducted, such as tether twisting and the sun's gravitational effects on the structure. As for the material, I think a suitable one will be produced within a couple of decades. A decade later, the project could well become economically viable.
We tend to throw predictions around, and discuss timelines of decades when it comes to projects of the future. Of course, everyone is entitled to their opinion. On this matter, however, I felt compelled to throw my hat in. If one is to take on the difficult task of forecasting the future, one should at least have a solid understanding of the situation at present.