United Nations Secretary-General Ban Ki-moon is at the centre of some of the world's most intractable crises and conflicts.
Yet despite the suffering he witnesses, the diplomat has released a statement telling the human race to have faith in our achievements - and the future.
The message, released to co-incide with the International Day for the Preservation of the Ozone Layer, says:
Not so long ago, humanity stood on the brink of a self-inflicted catastrophe. Our use of ozone-depleting substances such as chlorofluorocarbons (CFCs) had torn a hole in the ozone layer that protects us from the sun's harmful ultraviolet radiation.
But we tackled this challenge. Thirty years ago, the international community signed the Vienna Convention for the Protection of the Ozone Layer. Under its Montreal Protocol, the world united to slash the production and consumption of CFCs and other ozone-depleting substances.
Together, we have succeeded in putting the stratospheric ozone layer on the road to recovery by the middle of this century.
Of course, there's still work to be done. Ban went on to say that the UN looks forward to adopting the 2030 Agenda for Sustainable Development and doing further good work for climate change at the UN's Climate Change Conference in Paris in December.
The Secretary-General warned that the Montreal Protocol's success on hydrofluorocarbons (CFC replacements) isn't finished yet, but the collective international effort to save the ozone layer should inspire us moving forward.
[The success of the Montreal Protocol] shows what we are capable of when nations act together on a global challenge.