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What Shoreditch hipsters will tell you is confirmed by the environmentalists. It’s east London that makes west London cool.

And that perennial role – as temperature regulator rather than fashion barometer – will become increasingly important as the capital comes to terms with the impact of climate change.

More extreme weather is predicted over the next few decades and the city’s leaders are looking at the measures that are needed now to ensure the type and amount of building work in the capital does not make the problem worse.

Extreme rain storm events will create significant local flooding while any rises in temperature will be exacerbated by the “urban heat island” effect.

Greater London Authority adaptation manager Alex Nickson said: “We’re very keen to manage the overall urban heat island.

“Increasing the amount of green space in the city to bring down the temperature across the whole of the city can have a very marked effect.

“If we green the city substantially it may bring the overall temperature down by a degree but on an individual street it may bring it down by 8C.”

He cited the work of UCL’s Prof Mike Davies in modelling the potential impact of a fully urbanised east.

Using free space

Mr Nickson said: “If we were to build east London to the same density and availability of green spaces, what would that do to the rest of the city?

“His model shows we would raise temperatures significantly across the rest of the capital, particularly west London because, in hot weather, the prevailing winds are easterly.

“We need to make sure new east London is very green to keep west London cool, which is the reverse of how east London performed in the past.”

But the lack of free space in the capital is a bar to a number of greening programmes, including growing more trees (see panel) and developing pocket parks and rain gardens.

Prof David Balmforth, of the Institute of Civil Engineers, said: “What we are seeing in some cities is adaptation to the vertical – cascading rain gardens at different levels of high rise buildings.

“There is an opportunity to recreate some of the features we have been successful at implementing at ground level and turning that into something vertically.”

Other simple steps include putting a “lip” on entrances to the Tube. In Singapore, the metro system keeps operating despite significant floods because of the entrances are all raised by a metre, keeping the water out.

The London Assembly environment committee was told recently dual aspect apartments would help create natural air conditioning but there was little to stop developers building how they liked.

Mr Nickson said: “Single aspect buildings tend to be reliant on forced air movement for ventilation. But sometimes the constraints of the site mean you have no option.

“In a couple of places the residents have resorted to propping open their doors on the communal corridors which is clearly not what we really want.

“A lot of buildings that we see go up are highly glazed and entirely reliant on centralised ventilation plant for both heating and cooling.”

The wonder of trees

Trees are a one-stop solution to much of the impact of extreme weather, according to experts.

David Lofthouse, of the London Tree Officers Association, said Amsterdam didn’t have air conditioning – it had trees.

He said: “If you’re looking for a definition of a heat pump in reverse then you could use a tree.

“Or take cladding. If you have trees in your street, you have cladding of a sort. Trees slow down wind speeds so that’s going to save us from some of the effects of climate change.

“Flooding. Just the bio retention of a tree and its soil will help. Individually that’s a small advantage but if we’re talking about 30% of London being covered you have a major input.”

The 30% tree cover for London is a target for 2050. The figure currently stands at 20% and there is little optimism the extra 10% can be found.

Mr Lofthouse said: “We are not on course for that target. There are losses and new tree planting takes a long time to deliver.”

He added that people turning gardens into car parks and the loss of revenue budgets for local councils were added impediments.

Mr Lofthouse said: “It’s always thought the local authorities will be delivering this extra percentage of trees but, if 70% of London is under private ownership, we have to rethink that and to start looking at citizens helping us to deliver.”