What if I told you there was a single intervention we could deliver in our cities that would cool them during heatwaves, reduce flooding, scrub pollutants from the air, boost biodiversity, improve public health, and even reduce crime? You wouldn't believe me. But it's true. Image
What if I told you one study in Manchester found that shade from street trees reduced surface temperatures by an average of 12°C and that concrete surfaces shaded permanently by a bank of trees were cooled by up to 20°C in the summer? You wouldn't believe me. But it's true. Image
What if I told you that a single young tree planted in a small pit over an impermeable asphalt surface can reduce rain runoff by around 60%, even during winter when not in leaf? You wouldn't believe me, but it's true. Image
What if I told you a line of young silver birch roadside trees resulted in over 50% reductions in PM levels within the row of terraced houses screened from the road? You wouldn't believe me, but it's true. Image
What if told you that urban trees support a rich and diverse range of wildlife; providing important connectivity between isolated pockets of fragmented habitats, mitigating the negative effects of urbanisation for species such as bats? You wouldn't believe me, but it's true. Image
What if I told you that a high number of street trees close to the home is related to lower numbers of local prescriptions for antidepressants, even when controlling for a wide range of factors, such as deprivation? You wouldn't believe me, but it's true. Image
What if I told you that research has shown that for every 10% increase urban canopy cover there is a 15% decrease in violent crime and a 14% decrease in property crime, controlled for a wide range of socioeconomic factors? You wouldn't believe me, but it's true. Image
@CamillaAllen - fancy just unrolling this and taking it as my chapter, instead? 😜

Tweet II - Armson, D., Rahman, M.A. & Ennos, A.R. (2013) A Comparison of the Shading Effectiveness of Five Different Street Tree Species in Manchester, UK. Arboriculture & Urban Forestry, 39, 157-164
Tweet III - Bartens, J., Day, S.D., Harris, J.R., Dove, J.E. & Wynn, T.M. (2008) Can urban tree roots improve infiltration through compacted subsoils for stormwater management? Journal of Environmental Quality, 37, 2048-2057
Tweet IV - Maher, B.A., Ahmed, I.A.M., Davison, B., Karloukovski, V. & Clarke, R. (2013) Impact of Roadside Tree Lines on Indoor Concentrations of Traffic-Derived Particulate Matter. Environmental Science & Technology, 47, 13737-13744
Tweet V - Hale, J. D., Fairbrass, A. J., Matthews, T. J., Sadler, J.P., 2012. Habitat Composition and Connectivity Predicts Bat Presence and Activity at Foraging Sites in a Large UK Conurbation. Plos One 7, doi:10.1371/journal.pone.0033300.
Tweet VI - Melissa R. Marselle, Diana E. Bowler, Jan Watzema, David Eichenberg, Toralf Kirsten & Aletta Bonn, Urban street tree biodiversity and antidepressant prescriptions, Scientific Reports volume 10, Article number: 22445 (2020)
Tweet VII - Kathryn Gilstad-Haydena et al, Greater tree canopy cover is associated with lower rates of both violent and property crime in New Haven, CT, Landscape and Urban Planning Volume 143, November 2015, Pages 248-253
You can find out more about the programme I delivered in Hackney, London, below. If every local authority in the U.K had have replicated it - & Hackney is one of the smallest - we'd have planted 15 million trees in our towns and cities in just three years.
You can also find out below about how street trees and green infrastructure more generally can be used to radically reimagine our rapidly-warming cities; improving the quality of life their citizens...
...and you can find out below how rebalancing our relationship with the motor vehicles dominate our cities - while still benefiting from them - can drastically improve quality of life while reducing surface transport emissions.
...and, remember this, if your elected representatives won't listen, your duty is to the future of our children. In the immortal words of the Lego Movie's Lucy 'all of you have the unique ability...to be a groundbreaker, and I mean literally--break the ground!" #tacticalurbanism Image

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More from @jonburkeUK

Nov 10, 2022
1/ Recently, I wrote about the harassment campaign conducted against me by anti-LTN Horrendous Hackney Road Closures.

These are the same people who undertook a failed judicial review against the LTNs I delivered and, by all accounts, still owe the taxpayers of Hackney £10,000. Image
2/ Yes, the same anti-LTN group who mocked me up as a slave master and encouraged their gormless acolytes to lodge complaints about my support for LTNs appear to have turned out to be the bunch of dishonest, malignant grifters I warned you about.
3/ But who are Horrendous Hackney Road Closures and, crucially, where has all the money they raised gone?

I understand that failed Judicial Reviews don't come cheap, but by my reckoning they raised (and are continuing to raise) around £24,000 from over 1000 donations. ImageImage
Read 12 tweets
Oct 25, 2022
1/ Yesterday, we were treated to another statistics masterclass from anti-Low Traffic Neighbourhood journalist Andrew Ellson, of @thetimes.

Since I'm mentioned in the piece - a weird fixation - which cherry-picks DfT data to falsely imply LTNs increase mileage, this is my reply.
2/ Firstly, let's deal with Andrew's statement that I delivered the U.K's largest number of LTNs "on the basis that sat-nav apps were increasing the traffic on local roads."

This claim is false, as my introduction to Hackney Emergency Transport Plan (2020) shows:
3/ That is not to say I don't believe sat-nav-assisted displacement of motor vehicles from an overloaded main road network isn't a major issue for our cities. Because it is, as the following paper demonstrates: researchgate.net/publication/32…
Read 19 tweets
Oct 6, 2022
1/ You may have seen @Telegraph's & @TimHarford's coverage of recent DfT changes to road traffic stats, showing that 20.3bn miles were driven in London in 2019, not 22.6bn.

Low Traffic Neighbourhood enemies claim this means we don't need LTNs.

They're wrong. And I'll prove it.
2/ Not rubbishing @transportgovuk's data, but 1993 👉2019 miles driven on the U.K's roads annually increased by 100 billion. 70% came from cars/taxis, yet the DfT have not explained why their new estimates show just a 200 million mile increase in London in the decade to 2019.
3/ The 'smoking gun' for increasingly desperate Low Traffic Neighbourhood opponents, who've lost the argument, lost in court, and lost at the ballot box is that LTNs that based on the DfT's original data should be scrapped.

There are a couple of massive problems with this idea.
Read 16 tweets
Aug 8, 2022
1/ What if I told you - with the continent suffering another #heatwave and England in severe #drought conditions - that increasing forest cover in Europe by 20% would result in 8% more summer rain, with negligible effects on winter rain?

You might not believe me, but it's true.
2/ What if I told you that photographs over a 54-year period since the reintroduction of beavers to Alberta, Canada, showed they were associated with a 900% increase in open water and a "damatic influence" on mitigating extreme #drought?

You might not believe me, but it's true.
3/ What if I told you that if every household in the U.K had a water meter, we would reduce household water waste by a billion litres a day within three months and two billion litres a day within two years?

You might not believe me, but it's true.
Read 14 tweets
Jul 19, 2022
1/ I talk a lot about the cooling effects of street trees and green infrastructure during heatwaves, but one of the best ways of mitigating against high daytime temperatures is reducing high nighttime temperatures.

Let's talk about that.
2/ Concrete, tarmac, and other hard and synthetic materials - think the astroturf pitch (car tyre dump) or plastic play surfacing your Council recently installed - accumulate heat throughout the day and do not begin to release it until the external temperature begins to fall.
3/ Hard, man-made surfaces therefore turn cities into giant storage heaters, and this has a magnifying effect on the follow day's temperatures. Many studies have explained this effect, which can alter local nighttime temps by 17-25% (Ibsen et al, 2022).
Read 10 tweets
Jul 18, 2022
1/ I forgot to mention a secondary - and very important - reason to keep your houseplants well watered during a heatwave.

It's a little bit magical, but it *only works* if you have terracotta pots like this...👇
2/ So, you fill your watering can with tap/grey water - provided it's colder than the room temperature (which is very likely) then you go around the house and water your plants *with terracotta pots* until the soil is thoroughly wet.

That's when the magic happens.
3/ The water inside the plant pot is then absorbed by the naturally porous terracotta and drawn to the outer surface, evaporation at then not only releases the already cooled water in its gaseous state, but cools it further via the transition from liquid to gas.
Read 4 tweets

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