Scots may be used to moaning about our dreich, drab weather, but the nation’s grim climate could soon be a major draw for migrants.

The effects of global climate change will send droves of refugees north of the border to escape the heat of the south, a panel of experts has warned.

John Thomson, director of strategy at Scottish Natural Heritage, told a conference at the Royal Society of Edinburgh that “mass migration is a real prospect with the sort of temperature increases we’re talking about now”.

Speaking in a debate on the future of Scotland’s cities, he said areas in the south of England could become uninhabitable within our lifetimes unless drastic action is taken to adapt them for a hotter future. Other areas of the globe are also expected to suffer, with millions of people likely to flee countries such as India and Bangladesh.

Mr Thomson said Scottish cities would undergo “transformations which it is difficult for us to conceive of”, and that mankind must now face up to the fact that “human history has taken us to a point where we do not want to be”.

The bleak vision of Scotland’s fate was presented at the conference Brave New City: Snapshots Of The Future, organised by the Sustainable Urban Environments branch of the Engineering and Physical Sciences Research Council.

Panellist Riccardo Marini, who led urban planning at Glasgow City Council before moving to head up the equivalent group in Edinburgh, said Scotland could weather the brewing storm only by making the right planning decisions well in advance.

“Unless we understand that we need to plan for all these things in a way that allows for cultural diversity and all the other things to happen, we’re going to get it wrong,” he said, in response to the panel’s suggestion that Scotland’s “sense of place” could be altered by unprecedented levels of migration.

Italian-born Mr Marini said: “I consider myself very lucky to have been born where I was, and to have had the experiences that I’ve had. I have four boys, and I like to think their grandchildren will have similar kinds of experience, but they won’t happen in the same places.

“In terms of climate change, we are insignificant. The Alps will turn into hills. Venice will disappear. We as a species have the resources and inventiveness still to be relevant on this planet, but I think the change over places will be incredibly dramatic.”

Notions of heritage would have to change, Mr Marini added, as the future cultural make-up of Scotland’s cities dictated new tastes and traditions.

Dr Mike Groves, a geographer specialising in aerial photography, said there was now no doubt that climate change was happening.

He suggested that the most immediate impact on Scotland would be on employment, with places like Aberdeen forced to shift focus away from oil and traditional industries and towards renewable technologies and clean energy use.

Professor Paul Jowitt, president-elect of the Institution of Civil Engineers, said the country had little choice about whether or not to decarbonise its economy and make the necessary shift to lower-emissions living.

He said: “If we sit around and carry on as we are, what will happen is that China will become so powerful economically that there will be a step-change in Britain anyway because we won’t be able to afford the oil and gas.

“So, either you wait for the step-change to happen or you anticipate it and try to do something about it – but that does require leadership, which is not a characteristic very prominent in politicians.”

Mr Thomson suggested that “we have to think pretty radically about government structures” in the face of the problems posed.

He added: “Clearly a lot of these challenges are operating at a global scale, but equally we’re saying that they have to be tackled at a local scale as well.”

While the panel was optimistic about the possibility of redesigning Scotland’s urban areas to cope with the demands of the future, they warned that this in itself

could not be considered a solution.

Mr Jowitt said: “It’s worthwhile remembering that Noah saved biodiversity by building an ark to save it from a flood – he didn’t kill biodiversity by causing a flood.

“Just remember that. We need to prevent this stuff happening, rather than just making escape routes for when it does happen through actions of our own making.”