It is a world full of crises. Syria is entering its fifth year of war and its death toll is staggering - perhaps as many as 300,000 have died.

We have to unite. ISIL have committed unspeakable crimes, brutality ... I cannot describe the horror how a human being can be so cruel.... We have to mobilise all resources and the influence to stop this. 

Ban Ki-moon, UN secretary-general

The Islamic State of Iraq and the Levant (ISIL) is destabilising the wider region, using brutal tactics to control large parts of Iraq and Syria. 
And in the aftermath of the Arab Spring, countries like Libya and Yemen look close to becoming failed states.

Conflicts in Africa continue to rage and deaths from Ebola mount in the west of the continent.

In Europe, the Ukraine crisis continues, involving one of the world's superpowers, Russia.

And across the globe, governments are struggling to cope with more refugees on earth than at any time since the formation of the United Nations.

So, what are the vast challenges facing the world? And how should the UN and the international community respond?

With two years remaining on his decade-long term, Ban Ki-moon, the secretary-general of the UN, talks to Al Jazeera about the world's crises, his behind-the-scenes leadership style, and what it would take to defeat ISIL.

We also hear from Ban about whether the UN is long overdue for reform and why 2015 is a critical year for the UN's climate change and sustainable development goals.

Source: Al Jazeera