Spain, twice the area of the UK, with about three-quarters the population, is facing the challenge of the changing climate with some purpose, and with good reason.

In many ways, Spain is fortunate to be just outside the tropics, but not far enough north to be in our temperate zone, and traditionally that has meant borrowing from both zones.

This gives hot summers as the sub-tropical high pressure over the Sahara moves north, and then mild and wet winters as some of our depressions take a more southerly route in winter. Apparently, the rain in Spain falls mainly on the plain – or it did in the past.

However, that seems to be changing, as the boundary between the two climate zones is steadily moving north with the result that the temperatures on average have risen by 1.5 degC over the last century. Many of the coastal holiday resorts on the Costa del Sol have experienced record high temperatures in the last decade.

It’s not surprising that more than 90 per cent of the glacier ice in the Pyrenees has disappeared in the last 100 years, and this highlights water supply as one of the main problems facing Spain in the future.

This is particularly the case in the southern tourist and agricultural belt where water stress is the norm with competing demands from irrigation, for crops, golf courses, holiday housing and swimming pools.

Spain was allowed to increase its CO2 emissions by 15 per cent above the 1990 level under the Kyoto agreement to help development, but it has struggled and now emits 50 per cent more.

The country is now taking serious steps to rectify the problem. Recycling is reducing the amount of landfilled waste, as is energy from waste incineration, but the main problem is restricting the property boom.

Because Spain produces little coal, gas and oil, it now concentrates on renewable energy, particularly solar and wind, and by law all new properties and those renovated have to install solar panels. Rapid progress means that the northern Navarre region electricity will be 100 per cent renewable later this year.

As well as the normal photovoltaic cells on roofs which receive high feed-in tariffs from the National Grid, there are solar towers, surrounded by moveable mirrors that concentrate the sun, as well as plans to link into future Saharan electricity.

With more than 12,000 wind turbines, Spain is the third-largest developer globally, with even taller ones planned for offshore sites, such as near Cadiz, on the site of the Battle of Trafalgar.

Despite all this progress, Spain’s struggle with climate change could mean a million British ex-pats returning home.