Uploaded on 2015-12-14 by RebeccaCraig

Baltimore - up to 21C hotter than surrounding rural areas; on average, summers are 2.7C hotter in the city than in surrounding rural areas Boston - up to 15C hotter than surrounding rural areas; on average, summers are 1.3C hotter in the city than in rural areas Chicago - up to 21C hotter than surrounding rural areas; on average, summers are 2.2C hotter in the city than in surrounding rural areas Dallas - up to 19C hotter than surrounding rural areas; on average, summers are 3.8C hotter in the city than in surrounding rural areas Denver - up to 23C hotter than surrounding rural areas; on average, summers are 4.9C hotter in the city than in surrounding rural areas Indianapolis - up to 17C hotter than surrounding rural areas; on average, summers are 0.6C hotter in the city than in surrounding rural areas New Orleans - up to 16C hotter than surrounding rural areas; on average, summers are 2.2C hotter in the city than in surrounding rural areas San Diego - up to 23C hotter than surrounding rural areas; on average, summers are 0.6C cooler in the city than in surrounding rural areas Washington DC - up to 21C hotter than surrounding rural areas; on average, summers are 4.7C hotter in the city than in surrounding rural areas This information is very interesting. It could have been even better if the temperature difference information also had alongside an average population density. For non-US users of the website, it is hard to immediately imagine the differences in city and location that give the results. Q2. ![This is a photo of Bristol harbourisde, taken by Flickr user Andrew Gustar. ][1] ![A field about 40 minutes outside Bristol][2] [1]: https://edxuploads.s3.amazonaws.com/14501157779546897.jpg [2]: https://edxuploads.s3.amazonaws.com/14501160683002755.jpg The link to the Flickr account for the first photo is The link to his photo is https://www.flickr.com/photos/andrewgustar/11858749486/in/photolist-j4Vc53-cYqNaU-kggNb9-nnjf27-bx85b7-72mJ3q-nnfX6T-pKyTKr-obX3oc-xHZwhq-cv1in3-bezydt-kztuYv-9rLo2b-7hUgwU-pZxkkS-w5e1vZ-pZNugN-bezuTk-pKqpfX-aXVD4r-nfxztL-phpcgU-jDvaEx-p69yht-jMjizc-q7f8tc-qJMSEH-6LxGuU-rkHn4R-rB651p-jy3VsN-cbEgTG-kj1J3n-frLcBW-cRfHS5-dRHNFm-ehD25v-aLestn-hUKDcy-buRbsw-nhzdS9-q2EcBV-g3iC5H-pUZQAe-cWgyAJ-aaw5WW-nYyWM6-3gNMgh-aLRqtK I did not take the photo. It is quite difficult to find UHI data for the UK. At the time of posting, it was one degree warmer in Bristol than where the second photo was taken, on quite a cold night. Although the first city does not show Bristol's city centre, it is clear that there is substantial development, and many buildings in a relatively small area. A lot of these are multi-storey buildings, some of which are quite high. Bristol has mixed streets in the sense that some are wide and some are much narrower. It is also pretty green, with multiple park areas, and a lot of trees. However, it is a substantial city, the biggest in the south-west of the UK, and home to just under 430,000 people (2011 - likely considerably higher now). It is also a major transport nexus, with the M4, M5 and M32 all running close to, or into, the city. As such, there can be quite high levels of congestion although the city is relatively forward thinking in terms of sustainable transport options. In contrast, the second photo shows a very rural area, with just a few homes or farms spotted about the fields. The village where that photo was taken is home to fewer than 400 people. The main settlement is linear, with a wide road and low-level houses, with none greater than two storeys. Almost all the houses have gardens and there are fields spread amongst houses, and surrounding the entire village. In addition, while most households have at least one car, the number of people living in the village means congestion is very rare - unless people get stuck behind a tractor. From the village at night, you can see the lights of Bristol as an orange glow in the sky. These disparities in street canyons, population and population density, and car/bus etc numbers are all likely to account for the disparities in heat, as are the large number of trees and wooded areas near to the place shown in the second photo. Q3. As Bristol is a relatively small city, and the UHI difference does not appear to be great, there is not a significant amount of immediate need (in terms of thermal comfort) to address the UHI effect. The climate of south-west England is cool and often wet, with one degree making little difference to how comfortable people are. However, in terms of the effects on the environment and the planet, there is still a need to tackle emissions and energy use. I would recommend implementing at least one car free day a week in the city centre, and encouraging public transport use, including bikes, instead. I would also enact building controls to try to prevent areas of significant wind, and to think more carefully about how streets and buildings are designed, looking more coherently at urban design rather than simply isolated architectural design. Q4. I do not know of any policies designed to specifically mitigate the UHI effect, but the Mayor and Council of Bristol are making significant efforts to lessen the cities emissions and impact on the environment, among other areas, as the city of part of the Rockefeller Foundation's Resilient Cities project. Policies can be found here, with some documents available that go into greater detail. https://www.bristol.gov.uk/policies-plans-strategies/energy-and-environment