Climate change is the biggest threat to humankind – moreso than war, weapons of mass destruction or nuclear power – according to Hans Blix, former UN senior weapons inspector and former foreign minister of Sweden.

He said less than a dozen governments in the world were in possession of nuclear arms – while the world’s 7bn people all wanted access to energy, of which currently 85% comes from fossil fuel, against a background of rising greenhouse gas (GHG) emissions.

Blix spoke with IPE ahead of this year’s IPE Awards in Noordwijk, the Netherlands.

“My response to counter CO2 and other GHG emissions is two-fold,” he said. ”The first is energy efficiency and the second is nuclear power.”

While not opposed to wind and solar power, he believes those sources of energy are consolations for a public that dislikes fossil fuel and finds it hard to accommodate nuclear power.

He also said solar and wind power were ”intermittent” sources that needed a back-up, making them costly and problematic.

He added that the prioritisation of subsidies to renewable sources had in turn made nuclear energy more expensive.

Following his keynote speech at the IPE Awards Seminar he said: “We have failed in persuading the public that the risks [of nuclear power] are relatively small.”

He likened nuclear power to the fear of flying – many people were scared of it, and while it was breaking with nature, the risks were very small, and humans could not do without it.

“Contrary to what is sometimes written,” Blix told IPE, “the world is not milling with would-be nuclear weapons – in fact, the world is becoming more peaceful.”

The only two important flashpoints that remain, he said, are Taiwan and Kashmir, which are “mostly handled prudently”.

In his keynote speech at the Awards Seminar, he said: “While some 50 years ago, US president John F Kennedy feared there could be dozens of nuclear weapon states, the number has only increased from five – the P5 – to nine, by the addition of India, Israel, Pakistan and North Korea. On the other hand, Belarus, Kazakhstan and Ukraine surrendered their nukes to Russia, South Africa dismantled theirs and Iraq and Libya were stopped in their quest for the weapons.

“For my part, I would be more tempted at this time to ask whether the current dominant Western assessment of Iran is as flawed as that which was acted upon in Iraq. In the case of Iraq, a main reason presented for the attack was to destroy weapons of mass destruction – that did not exist. In the case of Iran, all agree there are no nuclear weapons. Are we witnessing a threat of an attack on intentions that may not exist? And, if bombardment of targets in Iran were to be undertaken, as is urged by some, what would follow?”

He continued: “The world knows these weapons are capable of causing mass destruction, and it is thought that a nuclear Armageddon could even destroy human civilisation. Yet, we might do well to remember that the mass destruction caused in Tokyo by incendiary weapons was of the same dimension as that at Hiroshima and Nagasaki. It was the terror aspect that made the awesome difference. We can only hope the taboo on nuclear weapons will continue to prevent their use and lead to their eradication – the global zero.”

Blix pointed out that the real weapons of mass destruction in today’s world were the small-calibre weapons used by soldiers, child soldiers, terrorists and civilians and causing “innumerable” casualties.

He pointed out that the safety of nuclear power had improved substantially, with only three major accidents occurring in our lifetime.

He added: “If you look at unplanned stoppages, we had about 70% availability in the 1970s, which has risen to a 90% availability today. That shows that [nuclear power plants] are running more reliably and more economically than in the past.”

He stressed that he was less worried about a potential small leakage of nuclear waste in 1,000 years’ time than an increase in global temperatures.

Blix said: “The techniques they have worked out for the disposal of waste are very reassuring. On top of that, it is a very sustainable source of energy, covering our energy needs for thousands of years ahead. Moreover, while it is a mature technology, it is not at the end of its technological evolution. We see today a lot of design and research going into new types of fuel and new types of reactors.”

Blix was director general of the International Atomic Energy between 1981 and 1997.