Climate change is "the most severe problem that we are facing today--more serious even than the threat of terrorism".
So said the then UK Chief Scientific Adviser, David King back in 2004.
It's a view that's been echoed by, among others, President Obama in this year's State of the Union address.
Eleven years on, King's comment came to mind as the UK parliament debated and approved air strikes on Islamic State in Syria at the same time as delegates from more than 190 countries were meeting at the UN climate summit in Paris to try to agree a deal to prevent catastrophic climate change.
The Syria vote took up many more column inches than the goings on in Paris despite the presence of world leaders, including Obama and his Chinese counterpart, Xi Jinping, at the opening of the summit.
Polls in Britain about the most important issues facing the World, indicate terrorism is seen as a much greater threat than global warming. It also seems public concern about climate change has declined since the last disappointing key UN climate summit in Copenhagen in 2009.
Why should this be when the scientific consensus is that unless the world takes measures now global temperatures will rise by more than 2 degrees and cause catastrophic changes in the climate that will pose a grave threat to all of humanity?
Some climate scientists think it's partly their fault. They believe they gave people the impression climate change would be more dramatic and also that it may be too late to do much about it. But climate change is likely to be gradual and psychology suggests if people think they can't do much about something, they will most likely carry on as usual.
But political leaders and the media also bear some responsibility.
When there is a terrorist attack, there is frequent talk about terrorism as an existential threat.
Prime Minister, David Cameron, himself has said he believes IS is an "existential threat" to the UK.
According to the dictionary "existential" means "relating to existence". So an "existential threat" to the UK is something that threatens the very survival of the country.
Does the Prime Minister really believe IS poses a threat to Britain's national survival in the same way Nazi Germany did in 1940?
Surely not?
But he is not alone in using this language - other politicians and media commentators have also liberally used the cliché - and it is bound to have an impact on public perceptions.
Anecdotally, I know well-informed people who agree with this assessment of the scale of the IS threat and dismiss climate change as exaggerated - when it is precisely the other way round.
The frog in boiling water is the analogy that's used to explain the lack of urgency about taking action to combat global warming. Then there's the fact that because climate science is developing all the time, there is always an element of uncertainty about it, even if the broad trends are clear.
However, there is already evidence that climate change will disrupt our way of life and threaten the existence of states.
The Pentagon and other defence ministries now recognise climate change as a threat to national security and see it as a driver of conflict.
One of the causes of the unrest that led to Syria's devastating civil war that may well end in the permanent disintegration of the country was prolonged drought and it's very likely climate change was a cause of that drought. It's this research Prince Charles was referring to in a recent interview with Sky News when he grabbed headlines by suggesting a link between terrorism and climate change.
The conflict in Sudan's Darfur region, which the UN estimates has killed around 300,000 and displaced almost 3 million, has also been linked to drought caused by long-term changes in climate.
Another problem when it comes to public perceptions of the two is that while terrorist attacks are sudden and shocking - that is the whole point of them in the eyes of the people carrying them out - climate change is incremental.
We humans also seem to find it far easier to empathise with the relatively small numbers of victims of sudden random violence than we do the large numbers whose lives are threatened by an creeping menace like climate change.
I don't intend to diminish the impact terrorism has on its victims and their loved ones.
If you are unfortunate enough to be in the vicinity of a terrorist attack then it is an existential threat to you.
But, unless you live in a handful of countries like Iraq, Syria, Libya, Nigeria, Somalia or Afghanistan, terrorism is not a threat to the future of your country. It's also not a threat to human existence. Climate change, on the other hand, probably is.