The Atlantic Ocean’s surface temperature swings between warm and cold phases every few decades. Like its higher-frequency Pacific relative El Nino, this so-called “Atlantic Multidecadal Oscillation” can alter weather patterns throughout the world.

The warmer spell we’ve seen since the late 1990s has generally meant warmer conditions in Ireland and Britain, more North Atlantic hurricanes, and worse droughts in the US Midwest.

However a colder phase in the Atlantic could bring drought and consequent famine to the developing countries of Africa’s Sahel region. In the UK it would offer a brief respite from the rise of global temperatures, while less rainfall would mean more frequent summer barbecues. A cold Atlantic also means fewer hurricanes hitting the southern US.

In the world of online dating, nothing is as it seems. But that doesn’t stop many of us from leaping to the wrong conclusions about people. A recent paper presented at the Annual Conference of the International Communication Association and reported on in the press suggested that when evaluating photographs from online dating profiles, men and women judge enhanced and un-enhanced photos somewhat differently.

For most British people the Dunkirk evacuation between May 26 and June 4 1940 was the most significant early event of World War II.

And in the 75 years since those momentous events it has come to occupy, in Penny Summerfield’s words, “an iconic place in British culture”.

I was initially rather excited to see that one of my friends and collaborators, Professor Shri Kulkarni from Caltech, had his picture littering my Facebook feed recently.

Unfortunately for Shri, it was because in an interview with National Public Radio he had described many scientists as secretly being “boys with toys”. Worse, he had said “You’re not supposed to say that”, which indicated that although it might be controversial, he said it anyway – which is typical of Shri.

There are many ways to interpret Shri’s comment, one is that scientists are boys, but as it turns out that is not what Shri meant.

When people do terrible things, it seems reasonable to believe we should have taken steps to identify them beforehand. If we can do that, then surely we can prevent them from doing harm.

The crash of Germanwings Flight 9525 in March, which appears to have been an intentional act, is an example. It shocks us (and understandably so) when a trusted professional harms those who have entrusted their lives to him or her.

So why not identify pilots at risk and take steps to prevent similar events from ever occurring again?

Because it is likely impossible, and maybe even counterproductive.

A recent World Health Organization report points to depression as the leading cause of illness and disability worldwide in 10- to 19-year-olds. Suicide by teens is ranked as the third leading cause of death in this age group.

A question that comes up time and again is whether schools should be involved in screening adolescents. But many parents and students find schools' involvement in mental health to be a violation of their privacy.