Why are Spain and Portugal so unbelievably hot right now?

Wildfires in the Algarve, Portugal, last weekend. Image: Getty.

Wildfires, drought and extreme heat have been the talk of the town and country across Europe this summer. Attention has now turned to Portugal and Spain, where temperatures at the weekend reached more than 46℃ in some parts of both countries – close to the all-time European record of 48℃, set in Greece in 1977. Records aside, the obvious question is what is causing the current Iberian heatwave and whether this might be a harbinger of the future.

A number of factors can be identified. These include unusually warm sea surface temperatures in the North Atlantic, a wandering jet stream and associated “blocking” pattern of high pressure, a very dry land surface, and climate change.

The anomalous size and position of warm water areas in the North Atlantic this summer have shifted the so-called “polar front” northwards. This is the point where warm air from the south meets cold polar air, and any movement in the front will affect the distribution of high and low atmospheric pressure right across the Atlantic. This in turn influences the flow of westerly winds across the Atlantic and over Western and Southern Europe, especially the thin and fast “jet stream” in the upper atmosphere.

This summer, an area of persistent high pressure or “blocking” has become established over Western Europe and the eastern parts of the Atlantic. Such blocking causes the jet stream to appear “lazy” and wander much further north and south than its average position.

Maximum temperatures for 6 August, with large areas well into the 40s. Image: Agencia Estatal de Meteorología (AEMET).

The upshot of all of this is that atmospheric blocking and a very snake-like jet stream prevents low pressure systems, and the “bad” weather they bring, from heading eastwards across Western and Southern Europe. In such a situation, the usual fluctuations between good, and not so good, summer weather are largely put on hold. Instead, as Portugal, Spain and much of Europe have experienced, clear skies, lots of heat, and very dry surface conditions become the norm.

In certain circumstances, persistent blocking can even draw in very warm air from elsewhere. This is what happened in Portugal and Spain, after intense heat caused an area of low pressure to form over Iberia. This “heat low” created the conditions for the flow of hot dry air from the Saraha Desert. Currently life in Portugal and Spain is not just in an oven, but more like a convection oven.


A warmer baseline means hotter extremes

Heatwaves in Portugal and Spain are not uncommon because this type of extreme weather is characteristic of the hot and dry summers in the Mediterranean climate region. Yet there is convincing observational evidence that heatwaves are happening more frequently across the Iberian Peninsula. Logically the question arises as to what extent the current heat is associated with climate change.

Although answering this question thoroughly would involve undertaking some well-designed climate modelling experiments, it’s safe to say that there is indeed a fair chance the current heatwave is associated with climate change. That is because heatwaves are now happening on a background of rising global temperatures so the base level of background temperature on which extremes are occurring has lifted somewhat compared to pre-industrial levels.

And what of the question on everyone’s parched lips: are the current extremes the “new norm”? The short answer is no, not right now, as extremes of over 46℃ still constitute rare events. However, analyses of the pronounced 2003 European heat wave, which affected both Portugal and Spain, indicate that the very similar extremes of August 2003 could be fairly normal by the 2040s.

The ConversationThis of course raises questions as to the habitability of places that already possess harsh summer climates. Most likely their sustainability will depend on the extent to which traditional climate adaptation strategies related to building and lifestyles can be pushed to the limit to cope with a new climate future typified by summers with temperatures in and over the mid 40s - and how flexible people and businesses might be to the idea of going elsewhere or literally underground during summer.

Glenn McGregor, Professor of Climatology, Durham University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

To boost the high street, cities should invest in offices

Offices in Northampton. Image: Getty.

Access to cheap borrowing has encouraged local authorities to proactively invest in commercial property. These assets can be a valuable tool for cities looking to improve the built environment they offer businesses and residents.

Councils are estimated to have spent £3.8bn on property between 2013 and 2017, funded through the government’s Public Works Loan Board (PWLB) at very low interest rates. Offices accounted for half of this investment, and roughly a third (£1.2bn) has been spent on retail properties. And local authorities were the biggest investor group for UK shopping centres in the first quarter of 2018.

Why are cities investing? There are two major motivations.

First, at a time when cuts are squeezing council revenue budgets, property investments can provide a long-term revenue stream to keep quality public services up and running. Second, ownership of buildings in areas marked for redevelopment allows councils to assemble land more easily and gives them more influence over the changes taking place, allowing them to make sure the space evolves to meet their objectives.

But how exactly can cities turn property ownership into successful place-making? How should they adapt the buildings they invest in to improve the performance of the economies?

Cities need workers

When developing the city’s property offer, the aim should be to get jobs back into the city centre while reducing the dominance of retail space. For councils who have invested in existing retail space and shopping centres, in particular, the temptation may be to try and retain their existing use, with new retail strategies designed to reduce vacancies.

But as the Centre for Cities’ recent Building Blocks report illustrates, the evidence points to this being a dead-end. Instead, cities may need to convert the properties they own so they house a more diverse group of businesses.

Many city centres already have a lot of retail – and this has not offered significant economic benefit. Almost half (43 per cent) of city centre space in the weakest city economies is taken up by shops, while retail only accounts for 18 per cent of space in strong city centre economies. And many of these shops lie empty: in weaker city centres vacancy rates of high-street services (retail, food and leisure) are on average 16 per cent, compared with 9 per cent in stronger city economies. In Newport, nearly a quarter of these premises are empty, as the map below shows.

The big issue in these city centres is the lack of office jobs – which are an important contributor to footfall for retailers. This means that, in order to improve the fortunes of the high street, policy will need to tackle the barriers that deter those businesses from moving to their city centres.

One of these barriers is the quality of office space. In a number of struggling city centres, the quality of office space on offer is poor. But the low returns available for private investors mean that some form of public sector involvement will be required.


Ownership of buildings gives cities the opportunity to reshape the type of commercial space on offer. Some of this will involve improving the existing office stock available, some will involve converting retail to office, and some of will require demolishing part of the space without replacing it, in the short term at least. Without ownership of the land and buildings on it, this task becomes very difficult to do but will be a fundamental part of turning the fortunes of a city centre around.

Cheap borrowing has provided a way not only for local authorities to generate an income stream through property investment. but also opens up the opportunity to have greater control over the development of their city centres. For those choosing to invest, the focus must be on using ownership to make the city centre a more attractive place for all businesses to invest, rather than hoping to revive retail alone.

Rebecca McDonald is an analyst at the Centre for Cities, on whose blog this article first appeared.