According to the most recent UN climate report, published Monday by the IPCC expert panel, "roughly half of the world's population currently experience severe water scarcity for at least part of the year".
Mr Connor told reporters that "uncertainties are increasing" when it comes to global water supply.
"If we don't address it, there definitely will be a global crisis," he said.เว็บคาสิโนยอดนิยม
UN Under Secretary General Usha Rao Monari, who is the official host of the UN Water Conference, told the BBC that resources would need to be managed more carefully in the future.
"There is enough water on the planet if we manage it more effectively than we have managed it over the last few decades," she said.