By Alessandro R Demaio, Harvard University

There’s been a lot of discussion about obesity this week. Whether or not it’s a disease (as it is in the USA now) and how this label would positively or negatively influence action taken by society and governments in addressing this large and growing burden.

This conversation is important, but I have noticed very often it ends with confusion. Questions around why we begin talking about obesity - and end discussing mental health, cancer, heart disease or diabetes. To make things even more confusing, the term ‘Non-Communicable Diseases’ might even be mentioned.

By Willem Vervoort, University of Sydney

Some 27 irrigation and dam projects are highlighted in the green paper for agricultural competitiveness released this week by agriculture minister Barnaby Joyce.

By Richard Pancost, University of Bristol and Stephan Lewandowsky, University of Bristol

By Daina Ramey Berry, University of Texas

People think they know everything about slavery in the United States, but they don’t.

They think the majority of African slaves came to the American colonies, but they didn’t. They talk about 400 hundred years of slavery, but it wasn’t. They claim all Southerners owned slaves, but they didn’t. Some argue it was a long time ago, but it wasn’t.

By Naomi Oreskes, Professor of the History of Science at Harvard University.

The term NIMBY – “not in my back yard"– has long been used to criticize people who oppose commercial or industrial development in their communities. Invariably pejorative, it casts citizens as selfish individualists who care only for themselves, hypocrites who want the benefits of modernity without paying its costs.

By Alfred Hermida, University of British Columbia

Whatever you do, don’t turn to Twitter for news about Ebola.

The volume and tone of tweets and retweets about the disease will make you wish you were watching the zombie apocalypse of The Walking Dead instead. It is much less scary.