Nearly 20,000 of the world's leading innovators, planners and directors are en route to Barcelona for Smart City Expo World Congress (SCEWC). Three days of discussions and exhibitions, from Nov. 14 to 16, will highlight city governance, mobility, safety, economy and sustainability — all from Catalonia's cosmopolitan capital.

It will be no easy feat to follow every conversation or debate that is sparked at the show, therefore social media will be a key resource to stay up-to-the-minute on chatter and trends. There will be over 420 speakers at this year's event, and while that's too many leaders to compile into a list, Smart Cities Dive picked out eight key figures that we plan to track on Twitter this week.

Bettina Warburg — @BWarburg

Warburg, a blockchain researcher, entrepreneur and educator, is also the co-founder of the innovation agency Animal Ventures. Her keynote session will cover "the rise of the decentralized economy," however her Twitter feed is another resource for information on technology advancements and machine trust.

Joan Clos — @Joanclos

Clos is an award-winning smart city leader who served two terms as Mayor of Barcelona, a term as the President of Metropolis, a term as President of the World Association of Cities and Local Authorities, and is currently serving as the executive director of UN-Habitat. His expertise in governance is featured through both his tweets and those of the @UNHABITAT account, which he frequently retweets.

Jason E. Roberts — @mannytmoto

Roberts, who founded Better Block Project, will speak this week about increasing community engagement in a "funny, smart, energetic and breathless" discussion. For more on his viewpoints about building involved communities, keep an eye on his Twitter account.

Geoff Mulgan — @geoffmulgan

Mulgan, the CEO of innovation foundation Nesta, is a self-declared "policy geek" who is "infinitely curious about how the world works." His discussion on cities amplifying collective intelligence will highlight new ways of developing solutions through creative thinking.

Beth Noveck — @bethnoveck

​As the director of The GovLab and professor of technology, culture and society at NYU's Tandon School of Engineering, Noveck is in-the-know with innovation and policymaking. Her Twitter is a virtual library of articles on city development, however to catch some of her more personal insights, be sure to attend her discussion on building smart cities from the bottom up.

Danielle DuMerer — @CityChicagoCIO

As the Chief Information Officer for one of America's most populated metropolitan areas, DuMerer is tasked with educating Chicagoans and fellow industry leaders on tech advancements and government solutions. While her Twitter mainly focuses on the Windy City, followers can pick up some valuable insights on overall city development.

Peter Marland — @Pete__Marland

Marland, the mayor of Milton Keynes, Buckinghamshire in England, is bound to bring some unique perspectives to SCEWC. His town has been touted as having the fastest growing economy in the UK, which has likely sparked some interesting insights to be shared at the expo.

Dimitri Zenghelis — @DimitriZ

Zenghelis has a lot to say about climate change — both at events and on his social media. As the head of climate policy at the Grantham Research Institute on Climate Change and the Environment (GRI), he will share informative insights on the state of global climate change and what cities can do to stay resilient.