what is this Font ?

Geograph  Suggested by rajailhamf 
ITC Stone Sans SemiBold  Suggested by frd 

According to this thread, it should be a custom font based on Stone Sans.

Name: Geograph
Designers: Kris Sowersby and Noe Blanco
Foundry: Klim
Release Date: Spring 2018

Back Story: Geograph is the official brand typeface of National Geographic, the cross-platform media company best known for its yellow-framed magazine. Two years ago, National Geographic announced it would be revamping its identity. As part of the overhaul, the company would be dropping “channel” from its TV programming, adding the tagline “further,” and rolling out a new visual identity courtesy of the studio Gretel that would live across the magazine, website, and TV channel. All this in addition to a massive redesign of its magazine. Geograph, a font family comprised of 24 styles, is the lynchpin to the brand’s fresh look.

Two years ago, National Geographic’s creative team got in touch with New Zealand-based Klim, asking if the foundry could design a custom font that would live as National Geographic’s main brand typeface across all of the company’s properties. At that time, National Geographic’s team had already been working with Gretel on the rebrand but was unhappy with the use of Verlag as the main display typeface and Neue Haas Grotesk as the main editorial font. They wanted an alternative for both without having to commission two different custom typefaces. In a lengthy explanation of the typeface, Klim founder Kris Sowersby recalls an email exchange between himself and National Geographic’s creative director, Emmett Smith: “Perhaps,” Smith wrote, “we could make something with a more neutral base with a ‘display’ version that ramps up its expressiveness.” Sowersby accepted the challenge.

OP posted this back in 2012.
There's no way this could be the 2018 font you're talking about.